Mysteries of Earth Revealed | Earth Science & Mystery | Solar System | Universe Mystery

The Mysteries Of Camouflage And Mimicry

2008-08-30T07:42:00.000-07:00

In nature, any species is sought after by other predator or prey species, which detect it through their senses (sight, hearing, smell). Victims can defend through venoms, unpleasant smells, run, or by deceiving the sensory input of their predators. One method is camouflage and mimicry. It is a balance between prey and predator bypassing this defense.

To camouflage (homochromy) in order to escape predators or to surprise the possible preys is to melt into the hues and shapes of the environment. The method can be simple or elaborated (the inversed shadow), making the animal melt into its environment.

Polar animals, like the polar bear and polar owl, are white. In the savanna, lions employ camouflage. They remain for large periods of time immobile in the bush without anybody being aware they are there, due to their tawny color. This tactic is especially efficient during the dry season, when the prey is scarce and the lions cannot afford losing food for being detected early by their prey. The same camouflage color is used by the African ground squirrels or prairie dogs, which use the autumn hues in their coat for deceiving predators.

Many insects (like grasshopers), snakes and birds (like parrots) have a green color that makes them difficult to distinguish in the grass or in the forest. Movie makers spend a lot of time detecting a leopard in the wild, even if they are abundant in an area... Most bottom fishes, like rays and angelfish, cannot be distinguished from the substrate. Some animals have cryptic shadow: they are dark above and light below, like tuna and many other fishes.

Homochromy can change with the season, like the ptarmigan and arctic hare, which are brown in the summer and white during winter.

Homotypy goes further than camouflage: the animals copy natural elements or plant organs with an amazing precision. Stick insects really look like a stick (their name Phasmatodea comes from the Greek "phasma" "phantom") and even imitate during their movements the shaking of a stick blown by the wind. Some Thai stick insects even mimic dead branches covered by lichens. The same imitation is made by some caterpillars and beetles (like Petrognatha gigas of western Africa). Leaf insects not only imitate a green leaf with nerves, but also the attack of fungi on the imaginary leaf! The same patterns are achieved by some Brazilian locusts.

The leafy sea dragons, relatives of the sea horses, can be differentiated with difficulty from algae.

Orchid mantis (Hymenopus coronatus) from southeastern Asia mimics so well a pink flower, that pollinating insects go straight into the killing arms of this predator, while others praying mantis from the same are mimic tree bark. Many moths too mimic tree bark.

Some caterpillars replace a plant bud before turning into a cocoon and the cocoon looks exactly like the replaced bud.
The tiny black toads (Oreophrynella) from the Roraima tepui in Venezuela have the color and texture of the rocks on which they live and this is also the case with many butterflies and the tree bark or dead leaves.

Some butterflies from Costa Rica completely lack color, being completely transparent. The frogmouths from Australia and nightjars have a plumage that makes them difficult to distinguish from the tree bark.

The chameleons' ability to change color is well-known, depending in which environment they are found at a given moment. But they are amateurs compared to the ability of the octopuses, cuttlefish or flounders.

Some animals play dead as an active method of defense: many predators will only eat prey which is alive...The opossum is the most famous when it comes to playing dead, hence the term "playing possum". Many snakes, too, use this strategy, and besides the immobility, they expel through some anal glands a decomposing corpse scent... Besides discouraging animals that eat only living prey, playing possum also convinces some large animals that the individual is no threat to their young.
Many insects (like wasps or caterpillars), spiders, venomous fish and snakes (like kraits and coral snakes) and toxic amphibians (like salamanders, fire-bellied toads and poison dart frogs) warn about their toxicity through bright colors and elaborated patterns.

That's why many species have developed mimicry: imitating the colors and patterns of the real dangerous animals, so that their predators won't attack them, being deceived.

There are flies imitating the color of the wasps and many non-toxic butterflies imitating toxic species of butterflies. Over 15 genera of non-venomous snakes imitate in Americas the model of the highly venomous coral snakes... The Myrmecium spiders mimic nasty ants.

There are even non-toxic moths imitating the ultrasounds emitted by toxic moths, being avoided this way by the bats. Sometimes, the predator imitates the prey, to get closer easier, like in the case of some beetles. Some parasite flies imitate the bumble bees in whose nest they depose their eggs.
The caterpillar of a hawk moth, Hemeroplanes ornapus, from Central America, has a length of 8-10 cm (3.2-4 in). When menaced, the pseudopods of the rear part hold the body (using sucking cups), while the thorax dilates to maximum, and this coupled with two fake shiny eyes and the hanging of the fore part of the body, make the caterpillar resemble a small snake.

Cleopatra's Mystery Lives On

2008-07-19T09:26:00.000-07:00

A ROMAN BUST OF CLEOPATRA
Reports of Cleopatra's beauty are apparently exaggerated, according to articles published in the British media. On the occasion of her exhibition this month in the British Museum in London, some reports in the media would have us believe that Cleopatra was hook-nosed, dumpy and had bad teeth!
A report in a "quality" publication said that "Cleopatra, the queen of ancient Egypt who seduced Julius Caesar and Mark Anthony with her supposedly irresistible beauty, has been revealed as short, frumpish and in need of a good dentist.. eleven statues show the queen as plain looking with a streak of sterness, and (she) appears to be plump".
Yet, throughout the lengthy reports, no hard evidence was given for the ugly cartoons published supposedly depicting the legendary queen. Furthermore, no explanation has been given for her magical influence and ability to seduce the most powerful men of her time. Her charm was attributed only to strength of character and mental charisma.
Even the statues on display and the coins carrying Cleopatra's head show a royal looking image with firm features and wide eyes. There may be a slight exaggeration of the nose proportion in one of the statues, but the coin illustrates a fine pointed nose, in good proportion to the face. Cleopatra was certainly not ugly.
Unless it is a publicity stunt for the exhibition, no self-respecting Egyptologist would take such descriptions of Cleopatra seriously. Even the curators of the British Museum admit that very few portraits of the queen survived, and they are anything but consistent. The evidence of contemporary description of Cleopatra was discounted out of hand, in these reports, because the writers, such as Cicero, were born a few years after Cleopatra's death. There was mention of her irresistible charm, her seductive voice and eloquent speech. Cicero wrote in the first century BC:
"Her character, which pervaded her actions in an inexplicable way when meeting people, was utterly spellbinding. The sound of her voice was sweet when she talked".
The evidence given for being fat, is also flimsy. Her ancestors were believed to suffer from weight problems! There is also no evidence of Cleopatra being only 5 ft. tall, except a description in a recent catalogue that she was "petite". As for the alleged teeth problem, that was attributed to "…eating the awful Egyptian bread"! In the same report, the ancient queen was described as "…taking care of herself. Her diet, including plenty of fruit and vegetables as well as fish and meat, was healthily balanced". This apparent contradiction was not explained by the writer.
The issue of Cleopatra's beauty is beyond doubt. The love of two powerful men of her era testified to that. Caesar went as far as putting up a golden statue of Cleopatra in the Temple of Venus in Rome, making her the first living human to share a temple with a Roman God - a frank recognition of her divinity and beauty by Caesar himself.

Humans Became Humans Just 4 Million Years Ago

2008-07-18T08:55:00.001-07:00

In a common evolutionary trunk, it is known that the orangutan is our cousin thrice removed, the gorilla is our cousin twice removed and the chimp is our first cousin (with which we share 96 % of our genetic information). A new research led by an international team from North Carolina State University, University of Aarhus in Denmark and the University of Oxford in Britain found that chimpanzees and humans split off
from a common ancestor just 4 million years ago, much later than the current hypotheses, that state for 5 to 7 million years ago.The research team compared DNA patches of humans and all big apes, man's closest relatives: the chimpanzee, the gorilla, and the orangutan.The researchers employed for the first time in this type of study a well-known type of statistical calculation, named the hidden Markov model which was developed in the 1960s and till now used only to speech recognition, reaching this different result about human differentiation. "Assuming orangutan divergence 18 million years ago, speciation time of human and chimpanzee is consistently around 4 million years ago. Primate evolution is a central topic in biology, and much information can be obtained from DNA sequence data," said Dr. Asger Hobolth of North Carolina State University.Each species has a molecular clock recording the speed at which DNA mutations occur. The speed may not be constant, but over large periods of time it evens, so in millennia the average is constant. The team focused on four DNA zones of the human, chimpanzee and gorilla.The results disagree with other investigations, showing that in just 400,000 years the human lineage split off from the common chimp-human ancestor.In May 2006, David Reich of the Broad Institute at the Massachusetts Institute of Technology and Harvard Medical School’s Department of Genetics got similar results for the splitting age (4 million years), but his team finally chose a 5.4 million years old for the divergence.Reich’s genetic analysis research rose the hypothesis that the early human ancestors and the chimp's ancestors could have interbred freely long after their separation. Another 2006 research made at the Georgia Institute of Technology discovered genetic evidence that, in fact, chimpanzees are closer to humans than to gorillas and orangutans.The molecular clock revealed that humans evolved one unique feature just a million years ago: our longer lifespan and our longer childhood, humans maturing sexually extremely late compared to apes.

The World's Oldest Known Child Mystery

2008-07-17T08:56:00.000-07:00

The remains of a 3-years old female of Australopithecus afarensis in the arid badlands of Afar (Ethiopia) at the Dikika site sandstones are those of the world oldest known child. The area is perhaps best known for turning up "Lucy," the 3.2 million-year-old skeleton of an adult female of the same species. The child, named Selam, lived 3.3 million years ago.The skull - of a monkey skull size - was spotted from a dusty slope in December 2000. The smooth brow and short canine teeth were typical for a hominid. Selam's discovery is reported in Nature by Zeresenay Alemseged, paleontologist at Max-Planck-Institute for Evolutionary Research in Leipzig, Germany; Fred Spoor, professor of evolutionary anatomy at University College London, and others.Researchers have spent five painstaking years removing the bones from sandstone, and to finish removing the sandstone from the child's bones will take several more years. Because it is very well preserved, the body may have been buried by sand and gravel in a flood. "It was buried just after it died," Zeresenay said. "That's why we found an almost complete skeleton, so maybe [drowning] could be the cause of its demise." Researchers hope this skeleton, because of its completeness, can provide much more information on details that Lucy and similar fossils couldn't. "Selam includes the complete skull, including an impression of the brain and the lower jaw, all the vertebrae from the
neck to just below the torso, all the ribs, both shoulder blades and both collarbones, the right elbow and part of a hand, both knees and much of both shin and thigh bones. One foot is almost complete, providing the first time scientists have found an afarensis foot with the bones still positioned as they were in life".The age of death makes the find especially useful, scientists say, providing insights into the growth and development of human ancestors. "It will teach us how our early ancestors grew up," Spoor said. "The only way you can evolve from one type of species into another is by growing up in a different way, because that's how you change." For instance, a prolonged, dependent childhood allowed later human species to grow larger brains, which need more time to develop after birth. While the adult A. afarensis had a brain slightly larger than a chimpanzee's, Selam's brain appears to have been smaller than a chimp's of the same age. This raises the possibility that A. afarensis experienced a more human-like pattern of brain growth. "For the first time we have insights that they may have grown their brains a little bit slower than your average chimp," Spoor said. "If you take more time to form your brain, it may well be that you make more intricate connections inside," the researcher added. "Or it may not be a positive thing—perhaps you live on poorer food or are a bit behind." Spoor favors the latter explanation in the case of these early hominids. "They haven't progressed over great apes at all, they've just changed their locomotion for whatever reason, but they were not necessarily any more clever than chimps were." "Selam also revealed just the second hyoid bone to be recovered from any human ancestor. This tiny bone, which attaches to the tongue muscles, is very chimp-like in the new specimen", Spoor said.While that doesn't directly reveal anything about language, it does suggest that whatever sounds afarensis made "would appeal more to a chimpanzee mother than a human mother," Spoor said.Selam already possessed the characteristics of her species. Scientists are especially interested in traits linked to locomotion. Selam supports the theory that A. afarensis walked upright on two legs, but also that early humans hadn't completely left the trees by that time. Scientists are excited to see how will Selam's foot look when fully excavated: human-like or chimp-like ?Scholars agree that A. afarensis was a creature that got around capably on two legs. But in the 1980s started the debate over whether the species was also adapted for life in the trees. Whereas A. afarensis has clear adaptations to bipedal walking in its lower body, its upper body exhibits a number of ape-like features, as Selam revealed. One camp held that A. afarensis had transitioned fully to terrestrial life, and that the tree-friendly features of the upper body were just evolutionary baggage handed down from an arboreal ancestor. The other side contended that if A. afarensis had retained those traits for hundreds of thousands of years, then tree-climbing must have still formed an important part of its locomotion. Like adult A. afarensis, Selam had long, curved fingers. But the shoulder blades, previously unknown for this species, are more like those of a gorilla, even if they present some human traits. The balance part of the inner ear is similar to that of the apes. This could indicate that A. afarensis was not as fast and agile on two legs as we modern humans are. The neck seems short and thick - like a great ape's - rather than the more slender human type. This limited the ability to decouple its head and torso, which play a key role in endurance running in our own species, keeping the head stable while running. "It's not out of the realm of possibility that they were still exploiting some of the arboreal habitats for getting off the ground at night and sleeping up there, or going back to familiar food sources." said Donald C. Johanson, Lucy's discoverer. C. Owen Lovejoy of Kent State University disputes the assertion that the scapula looks like that of a gorilla. "It's primitive, but it's really more humanlike than gorillalike" says Lovejoy, a leading proponent of the idea that A. afarensis was a dedicated biped.The discovery of the famed Laetoli footprints in 1978 closed the debate, he states. That trail showed that A. afarensis did not have a grasping big toe. Lacking that prehensile toe, Lovejoy says, A. afarensis could not move about effectively in the trees. Selam is a " good example of mosaic evolution". " It looks like natural selection is selecting for bipedalism in the lower limb and pelvis first, and things that are not really used in bipedal locomotion, such as arms and shoulders, change at a later stage", says Johanson. The skull also shows a mixture of traits, with its primitive hyoid bone, and human pattern of brain growth. Once, the region where afarensis lived was much wetter, with lush woods and grasslands with a savanna fauna, as nearby excavated fossils showed.

The Mystery Of Earliest Human Settlements In Russia

2008-07-15T08:42:00.000-07:00

The discoveries made at an archaeological site on the banks of the River Don in southern Russia revealed for scientists the earliest known settlement of modern humans in Europe, dated 45,000 years ago.The artifacts were covered by sediments including a layer of volcanic ash from an eruption in Italy dated to about 40,000 years ago, thus the site must have been inhabited a few millennia earlier.

"The team, led by the Russian Academy of Sciences and the University of Colorado at Boulder, founs stone, bone and ivory tools under ancient volcanic ash on the Don river in Russia 400 km (250 miles) south of Moscow, " said John Hoffecker , a fellow of the school's Institute of Arctic and Alpine Research.

The site also contained perforated shell ornaments, which must have been achieved from the Black Sea coast, some 300 miles (500 km) south, and a carved piece of mammoth ivory apparently the head of a small human figurine. "It could represent the earliest known piece of figurative art in the world," said Hoffecker. "The big surprise here is the very early presence of modern humans in one of the coldest, driest places in Europe," Hoffecker said. "It is one of the last places we would have expected people from Africa to occupy first." Neanderthal people were known to have inhabited Europe for 300,000 years, before the arrival of modern humans, but - undoubtedly - the Kostenki site was inhabited by Homo sapiens. "Although human skeletal remains in the earliest level of the excavation are confined to isolated teeth, which are notoriously difficult to assign to specific human types, the artifacts are unmistakably the work of modern humans," Hoffecker added. "Unlike the Neanderthals, modern humans had the ability to devise new technologies for coping with cold climates and less than abundant food resources," he said. "The Neanderthals, who had occupied Europe for more than 200,000 years, seem to have left the back door open for modern humans," he added.At Kostenki a group of 20 sites was excavated for decades. In the past, Kostenki "yielded anatomically modern human bones and artifacts dating between 30,000 and 40,000 years old, including the oldest firmly dated bone and ivory needles with eyelets that indicate the early inhabitants were tailoring animal furs to help them survive the harsh climate," the researchers said. Other artifacts discovered included simple tools such as drills and awls, and a spade made from antlers, but the site also harbored bones of prehistoric animals such as woolly rhinoceros, bison, mammoth and moose. Worldwide, the oldest proof of modern humans outside of Africa comes from Australia and dates 50,000 years back.This discovery from Russia pleads for a relative early migration out of Africa, earlier than 50,000 years ago.

The Mysterious Protein That Revolutionized Insect Sight

2008-07-02T09:54:00.001-07:00

A compound eye is a visual organ found in insects and some crustaceans.Such an eye has 12 to 1,000 ommatidia. These are tiny sensors that distinguish between brightness and darkness, and sometimes can detect color, and structurally correspond to the ocular globe of the vertebrates. The image perceived by the arthropod
is a combination of inputs from the numerous ommatidia, which are oriented to point in slightly different directions. Unlike other types of eyes, a compound eye does not have a central lens or retina, resulting in poor image resolution; however, it can detect fast movement (flies) and, in some cases, the polarization of light (bees). Each ommatidium consists of a lens and several visual receptor cells parallel to each other or slightly twisted. Recently, a team of biologists at the University of California, San Diego have discovered that the presence of a protein in the compound eyes of the fruit fly (photo)(which glow at center due to a fluorescent protein) enables the formation of distinct light gathering units in each of its 800 ommatidia. This evolutionary "open system" enabled insects to make significant improvements in visual acuity and angular sensitivity. Most insects, like beetles, bees and mosquitoes (which are in fact primitive flies) species have the light-gathering units fused together into a "closed system."One of three proteins needed to form these light gathering units is present in the visual system of fruit flies, house flies and other insects with open eye systems, but conspicuously absent in species with closed systems. The loss of this protein, called "spacemaker," can convert the eyes of fruitflies—which normally have open eye systems—into a closed one. In contrast, the introduction of spacemaker into eyes with a closed system transformed them into an open one. "These results help illustrate the beauty and power of evolution and show how ‘little steps’—like the presence of a single structural protein—can so spectacularly account for major changes in form and function," said Charles Zuker, a professor of biology and neurosciences at UCSD.

The Mystery Of First Human Embryo Clones

2008-06-27T02:01:00.000-07:00

A cloned Scarlet Johanson may be the dream of any man and a Californian company has just made the first step toward this purpose: for the first time, scientists have achieved cloned human embryos using DNA extracted from adult skin cells, as reported in the Stem Cells journal. "That's an important first step toward generating embryonic stem (ES) cell lines from such embryos, which can be used to study and treat diseases such as diabetes and Parkinson's," stem cell researcher George Daley of Harvard Medical School in Boston said.By achieving cloned human embryos starting with cells from patients with various diseases, researchers hope to come with new treatments using the transplant of cloned tissues and even organs.
In 2007, a team managed to turn skin cells into ES-like cells, but the real embryonic cells are more pluripotent cells that can turn into any cell type, generating any type of tissue. The team at Stemagen, a biotech company based in San Diego, operated with skin cells donated by two men and 25 eggs (oocytes) donated by women at a fertility center. The nuclei (comprising DNA) from the eggs were removed and replaced with DNA from the male skin. "Two of the eggs became 5-day-old embryos, or blastocysts, that were clones of the male donors. That's an "unexpectedly high" success rate," the company said in a statement. "The key to the team's success was utilizing fresh, mature oocytes from females of proven fertility," lead researcher Andrew French said. Double DNA analysis showed that two of the blastocysts possessed the DNA of the male donor cells. The mitochondrial DNA was clearly from the oocyte while the nuclear DNA from the male skin. The goal of the researches is to extract ES cells from the inner cell mass of cloned blastocysts and create a new cell line from them; this will eliminate any doubt concerning the method's effectiveness. Those ES cells could be used in treatments. Some doubt that this could be so easily achieved, pointing to the presence of chromosomal abnormalities in the achieved embryos. "The blastocysts in the paper look very unhealthy. I would guess these clones are abnormal, too." said Robert Lanza of Advanced Cell Technology in Worcester, Massachusetts. Andrew French responded that the donor clinic "has got pregnancies from IVF [in vitro fertilization] embryos that look similar." Two months ago, another team achieved ES cells from cloned monkey blastocysts, a first in the case of primates.

The Mystery of River Nile

2008-06-03T09:23:00.000-07:00

This river is the maker of the oldest civilization recorded by the historical sources: 5,000 years ago, the Egyptian state emerged on its banks. It is best known as the longest river on the planet. Nile is consensually considered so as it has 6,695 km in length, even if some say that Amazon is longer (6,800 km). The problem is that nobody could tell where Amazon ends, due to its huge mouth. Anyway, while Amazon is the mightiest river on the planet (with a debit of 200,000 cubic meters/second, 20 % of the freshwater volume penetrating the oceans), Nile has a 60 times lower debit, as it does not receive any affluent on its last 2.400 km (1.500 mi). Moreover, the Nile's debits fluctuate a lot, as it receives the most abundant waters during the rainfall on the Ethiopian Plateau. But the role played by the Nile in human life and history is much more important. The Nile starts from molten snow and rainfall, which make torrents like Mobuku and Semliki in the Ruwenzori Mountain (a glacier-covered equatorial mountain, with a maximum height of 5,119 m / 17,633 ft). Semliki enters Lake Albert. Another southern source is located in Burundi, at a height of 2,050 m (6,830 ft): Kasumo. Then, from the large Lake Victoria, the Nile starts under the name Kagera for emptying itself into the Mediterranean, on the place where 2,300 years ago Alexander the Great founded the famous city of Alexandria. The river crosses Burundi, Uganda, Sudan and Ethiopia before entering Egypt. From Lake Victoria, the Nile starts through cascades that are 4 m (13 ft) tall and 150 m (500 ft) wide. The Nile enters Lake Kyoga, which acts like
a sponge. Further, two granite bars make a strait, just 6 m (20 ft) wide, making the Nile fall from 40 m (133 ft), forming the Murchinson Falls. Further on, the Nile enters Lake Albert and from this lake, it heads northward. The Nile is swift in this portion, being called Bahr-el-Gebel (the river of the mountains). Then, the Nile crosses a huge area of swamps, called "Sadd" (halt) by the Arabs. This is a world dominated by papyrus twice the height of a man. The area is as large as the Sargasso Sea and is difficult for navigation.After 750 km (480 mi), with the No Lake, the world of the swamps has ended. Until the confluence with the Blue Nile, the proper Nile is called the White Nile (Bahr-el-Abiad). The river has lost much of its forces in the swamps as much of its waters evaporate here. But it is strengthened by Sobat River, an affluent coming from Ethiopia. It is so large now that the Arabs call it "Bahr" (sea). The river has crossed 2,600 km (1,650 mi) and the landscape along its banks turns gradually from steppes to desert, while "Black Africa" turns into the world of the Islam. After the dam Gebel Aulia, the Nile approaches Khartoum, where it will be joined by the Blue Nile. There are more 3,000 km (1,900 mi) to the Mediterranean. The Blue Nile has 1,500 km (900 mi) and its source is in Sakala (Ethiopia), a sacred place for the Ethiopian Christians. After emerging at the height of 2,900 m (9,660 ft), it crosses Lake Tana (at 1,760 m (5,860 ft). From Lake Tana, the river crosses various cascades. In Sudan it is called Bahr-elAzrak (ashy river). The two Niles join after the second bridge of Khartoum. The Blue Nile comes with a daily debit of 141 million cubic meters of water, representing 80 % of the total debit of the Nile. The river is called after the confluence Bahr-el-Nil. In Karthoum, Nile receives also its last affluent: Atbara River, coming filled with mud (varying from red to green) from the Ethiopian Plateau. Now the Nile is 2-4 km (1.2-2.4 mi) wide and is spotted with islands. Through the desert crossed by the Nile, vegetation growth is restricted at a fringe of about 1.5 km (1 mi) along the river's banks and life is concentrated on a strip few km wide alongside the banks. From Khartoum, the Sudanese capital, to Assouan, 6 cataracts are found on the Nile. The first cataract is located 200 km (125 mi) north of Khartoum. On the fifth cataracts, papyrus beds, gone from Egypt since the time of the pharaohs, can still be seen.
This portion in northern Sudan is the area were the ancient kingdom of Nubia flourished. For a while, even Egypt was ruled by Black Nubian pharaohs. One of the longest reservoirs on Earth was built at Assouan on the Nile from 1958 to 1970: Lake Nasser, which is 550 km (344 mi) long and with a maximum width of 35 km (22 mi). The reservoirs lay between Egypt (mostly) and Sudan, and required the removal of the temples of Abu Simbel to a 64 m (213 ft) higher place. The Nile made possible the development of the oldest state known, Egypt, in the middle of the Sahara desert, one of the toughest on Earth. But the Egyptian civilization thrived on its banks 10,000 years ago, while the Egyptian empire rose 5,000 years ago. 12,000 years ago the Nile was much stronger, crossing a savanna, where nowadays we see only dry desert, and receiving numerous strong affluents on its course. But 10,000 years ago the drought was already felt. 6,000 years ago, two cultures were known in Egypt: the Merimde Culture in the north, around Nile's Delta and Badarian Culture in the middle Egypt, around the city of Asyut. From the union of these two cultures, the first great nation-state in the history rose, flourishing for three millennia and leaving us awesome monuments, like the monumental pyramids at the Abu Simbel, Karnak, Philae. The agriculture in the Nile Valley was strictly connected to the annual flooding, which occurred between July and September, covering huge areas. The inundations meant the Egyptian agriculture did not require irrigations. Still, some crops required stocking water and irrigation. Of course, the Nile was for the Egyptians the backbone of their unity and the main transport route. The Nile allowed a centralization of the political, military and economical power that permitted the emergence of a huge trained work power necessary for the building of the huge monuments, priceless values of the human civilization. Due to the steady food supply provided by the fertilizing Nile, Egypt was one of the most stable ancient states till its conquest by the Romans led by Julius Caesar in 30 B.C. Even today, Egypt is the most populous country in the Middle East and North Africa, due to Nile that can provide the food (directly and indirectly) for such a large population. At Cairo, the Nile is just 800 m (0.5 mi) wide. Its meanders are hidden by the high buildings. Many changes have occurred in the last decades: new canals, dams and bridges. Nile Delta, made by the two mouth of the river, Rosette and Damiette, is a triangle with the side of 200 km (125 mi). 20 million people inhabit this "agricultural lung". The delta is crossed by a network of smaller arms, canals and ditches. From its forking point, the Nile still has to make 500 km (310 mi). The Eastern Nile heads northwards after Zifta dam, avoiding Tantah, a quite contaminated industrial center, but crossing Mansurah, a 200,000 inhabitants city, joining Lake Menzaleh, and then reaching Damiette, a furniture center, before entering the Mediterranean. The western Nile, after Sa el-Hagar (built over the ancient Sais) encounters the Edfina dam, which protects the fields from the invasion of the sea waters. Still, in the last decades, the salinity of the irrigation waters has risen. Through the palm oases, the branch reaches Rosette, a town turned famous because here the famous hieroglyph basalt stone, used by Champollion to decode the ancient Egyptian hieroglyphs was discovered. Here, at Rosette, the Nile is as wide as in Cairo, with banks invaded by palm trees.

A Mystery -The Petrified Forest

2008-05-30T11:27:00.000-07:00

One of the wonders of the American southwest is found in northeastern Arizona: an enormous petrified forest, a real geological treasure the scientists learned about to the end of the 19th century.
Petrified Forest National Park from Arizona comprises a surface of 218,533 acres (341.5 sq mi; 885 km²) of petrified wood, mostly of the coniferous species Araucarioxylon arizonicum, 170 million years old, since the Jurassic epoch. In some moment, whole forests were flooded. These conditions made the wood to get mineralized, turning into quartz, jasper and agate. Normally, the wood would have turned into coal. After that, the forest was covered by red and yellow sediments, which later were removed by wind and water. This explains the preservation of the fossil wood and the large variety of colors some specimens exhibit. The red and yellow hues are the result of large particulate forms of iron oxide, the yellow being limonite and the red being hematite. The purple hue is caused by extremely fine spherules of hematite distributed throughout the quartz matrix.The trunks did not grow there, but were carried by waters, which piled them, making deposits up to 50 m (160 ft) thick. But in this case, it was mineralized. For its exceptional beauty, the petrified wood was early exploited for making furniture, jewels and art objects. Large surfaces of the petrified forest were even dynamited. In 1906, the area was declared National Monument (protected by law) and in 1962 its status was turned into National Park. With all the protective measures, the stealing of the fossil wood continued, the statistic confirming that annually 12 tonnes of the petrified wood are extracted illegally. Araucarioxylon were trees 60 m (200 ft) high that measured more than 60 cm (2 ft) in diameter. Fossils frequently show boreholes of insects, as well as fossilized hives of prehistoric bees.The genus Araucarioxylon is close or even synonymous to the modern genus Araucaria, which today is restricted to southern South America, Australia, New Caledonia, New Zealand and Norfolk Island.

Females are Tougher Than Males

2008-05-29T11:13:00.000-07:00

Are men really tougher than women? Girls learn to read before boys do, get better marks in college, and even their brain contains more gray matter. Come to think of it, as early as in fetal state, males are medically weaker than females. The sex ratio at birth is slightly in favor of the boys. But in the womb, boys are more vulnerable to maternal stress and the male fetus is more predisposed to premature birth, congenital malformations and cerebral paralysis. After birth, boys are four times more likely to experience disorders of development and learning (autism, stuttering, dyslexia), ten times more likely to develop some type of attention
condition with hyperactivity.The animal world is no different from our own, as showed by a new study carried out by Maria Bogdanova and Ruedi Nager from the University of Glasgow, and published in the Behavioral Ecology and Sociobiology journal. Male seagulls were found to be more vulnerable to their environment during embryonic development when compared to females. In many bird species, siblings hatch in an echeloned manner, and that's why chicks in a brood can have different ages, the younger ones being often outcompeted and displaying decreased survival ability. Birds have a well-developed auditory system during the last stage of incubation and embryos communicate with each other via sounds. These calls seem to be a signal for later-developing embryos about forthcoming brood competition; they can even react to them by speeding up their hatching time to diminish their age odds. In this new research, the social environment of herring gull embryos was manipulated to see how sibling contact during embryonic stage impacted the developmental rate in males and females. The researchers took the last-laid eggs (gulls lay 3 eggs) and incubated them either alone or together with other eggs (receiving information about the presence of older embryos). The hatchlings were raised together with nest mates or alone. These situations impacted hatching duration and fledging (when the young have feathers developed enough for flight) condition. Male eggs incubated in isolation hatched more rapidly than females but both genders had equal, relatively good condition by the time of fledging. Oppositely, in common clutches, males hatched more slowly and fledged in much poorer conditions when compared to females, no matter if cared singly or in a brood. It seems that females have a better resistance to the challenges of echeloned hatching.

Deep Mystery : How Can French Clay Kill Flesh-eating Bacteria?

2008-04-24T10:49:00.000-07:00

When the Buruli ulcer, nasty flesh-eating eruptions of Mycobacterium ulcerans, broke out in Ivory Coast a decade ago, two French green clays worked best, removing the specter of surgery or amputation. One clay induced excruciating pain, but in several days it induced skin tissue regeneration on the open wound. A second variety, mixed with shea butter (a plant oil), induced no pain and cured the oozing ulcer in several months. In France, these iron-rich clays have been used for centuries.Now a team led by mineralogist Lynda Williams of Arizona State University (A.S.U.) in Tempe has been attempting to explain the healing powers of the French clays."This clay was unique in that they were very small particle size, 200 nanometers, or 1/400 the width of a human hair," said Williams. The producer companies (Agriletz and Agricur) did not expose the source of the clays, but French mineralogists guess they are made of volcanic ash deposits from the French Massif Central. First tests were made on Escherichia coli, the all-over present food infecting bacteria, but after that on all kinds of bacteria, from Salmonella to antibiotic-resistant Staphylococcus aureus. "That's when we first discovered that the first clay promoted bacterial growth and the second killed it," said Wiliams. "The strains that we are using are the same ones that pharmaceutical companies use to test their antibiotics. All of the gram-negative pathogenic bacteria to humans that we've tested, we can kill completely." said co-author Shelley Haydel, A.S.U. microbiologist. Like many antibiotics, the clay stopped the reproduction of those bacteria it could not kill. "The number of cells we start with is 107 Staphylococcus aureus. After 24 hours, that level reduces tenfold." said Haydel. But the tests have not solved the puzzle: how do they do it? Chemical analysis found no particular minerals or metals in the clay explaining the antibacterial powers and added water did not affect this effect.
The killing powers were preserved even when the clays were heated to over 1,000o F (550o C), but lost over 1,650o F (900o C), when the clay's structure was affected, leaving behind only the heaviest elements, like radioactive cesium, selenium and toxic arsenic. "E. coli can tolerate 200 parts per million and we're talking about 50 ppm. The clay's antibacterial effect appears to be chemical rather than physical, because its strength diminishes as it loses positively charged molecules and it does not smother the bacteria or cause its cell walls to burst. After six hours, you can see a [bacterial cell] surface that is kind of wormy or grainy. It doesn't look like something is precipitating at the surface. Maybe something is going into the cell and damaging it that way." said Williams. The clay could combine the antibacterial powers of its many various elements. "I think these clays are buffering water to keep whatever's toxic to bacteria in there. If we remove the clay from water, I think it's not going to work." said Williams.
The age also affects the clays' power. "We went back and got some from the same batch and it didn't kill. This clay has been sitting outside in a pile for 10 years. It could have oxidized and maybe the oxidation state has affected the antibacterial properties." said Williams. Two other clays with similar antibacterial powers have been detected. "They're all different mineralogically, though they have a general structure in common. We're trying to compare the properties of these antibacterial clays and see what's going on." said Williams. Researchers do not neglect the variant that clays could boost the human immune system reaction to the infection, which M. ulcerans can inhibit. "Even if you removed the antibacterial properties, do the clays have any effect on wound healing? What is the body's response? Are you stimulating tissue regeneration? We already use maggots and leeches in hospitals. Why don't we use clays?" said Haydel.

The Mysterious Crickets of Hawaii

2008-04-20T01:58:00.000-07:00

A new study by UC Riverside evolutionary biologists revealed that in only a few generations, cricket (Teleogryllus oceanicus) (photo) males in Kauai island (Hawaii) experienced a mutation that left them incapable of using sexual signal songs to attract females. The new male crickets - even if they lacked the singing apparatus - are able to mate successfully with females. They changed their behavior, surpassing what seemed a harmful mutation increase. More
than 90 percent of male crickets on Kauai changed in less than 20 generations from normal to non singing. The mutation protects male crickets from a deadly parasitic fly (Ormia ochracea) that locates them by using their song. The fly deposits larvae onto crickets; these enter into the cricket, eat it from inside, and subsequently kill the cricket, after that emerge from its body. Of three Hawaiian Islands (Oahu, the Big Island of Hawaii, and Kauai) where both the cricket and fly are found, Kauai has the highest prevalence of the parasitic fly, but also of non singing male crickets. "With each visit we made to Kauai since 1991, we observed fewer crickets," said Marlene Zuk, professor of biology."In 2001, we heard only one calling male. But then in 2003, although we heard none of the male crickets calling, we found they were not only in high abundance but nearly all of them also had female-like wings, lacking the fine structures needed to produce song."Male cricket populations in Oahu and the Big Island - as well as descendants from eggs collected on Kauai before 2003 - continued to show normal wings. Only Kauai displayed mutant male crickets in 2003. "Loss of calling clearly seems to be protecting the male crickets from the deadly fly," Zuk said. "But this protection has a heavy price: the loss of its sexual signal. This is obviously a huge loss for the cricket, akin to, say, finding that all peacocks in a forest have lost their tails. One might ask how then do female crickets locate silent males?"It seems that mutant males behave as 'satellites' to the few remaining male crickets that can call, by congregating near the singing males, and so females find and mate them, as field experiments suggested. "While we were surprised by the extraordinary speed at which the mutation spread, what is more interesting is that, ordinarily, you would expect such a change in wing morphology to quickly disappear, because males couldn't attract mates," Zuk said. "Instead, the behavior of the flatwings allows them to capitalize on the few callers that remain, and thus escape the fly and still reproduce. This is seeing evolution at work."

The Mysteries of Chinese Writing

2008-04-16T02:28:00.000-07:00

Chinese writing is thought to have resisted for 4,500 years. And the greatest danger for it was the attempt of replacing it with the Latin script. But this did not work due to ethno-political reasons: while those from the Han ethnic group regard themselves as Chinese proper, they speak 13 different languages (not dialects!), even if amongst them, Mandarin is the most spoken and official. The phonetic Latin writing revealed they cannot understand one another by speech but by their common writing, which makes use of about 5,000 morphemes. Combinations of characters create Chinese words.
From the time of Qin Dynasty (which give the western name of China) onwards, a standard written language has filled the gaps between the various Chinese languages.But now Chinese archaeologists investigating ancient rock carvings claim that they have discovered proofs that modern Chinese script is thousands of years older than people believed. Scientists have detected over 2,000 pictorial symbols, as old as 8,000 years, on cliff faces in the north-west of China. The ancient symbols display a strong similarity to later morphs of ancient Chinese characters. Scholars had thought Chinese symbols came into use about 4,500 years ago. Based on the Damaidi carvings, found in the 1980s, covering 15 sq km (5.8 square miles) and depicting over 8,000 individual figures like the sun, moon, stars, gods and scenes of hunting or grazing, it was believed that the Chinese writing is about 4,500 years old and pottery inscriptions from Henan province (central China) were of similar age . "We have found some symbols shaped like both pictures and characters," Li Xiangshi, a cliff carving expert at the North University of Nationalities in Ningxia Hui autonomous region, told Xinhua news agency. "The pictographs are similar to the ancient hieroglyphs of Chinese characters and many can be identified as ancient characters." To make a comparison, the Greek script is about 3,000 years old. The Latin script, based on the Greek, is even younger, about 2,500 years old. The Arab script is younger, almost 1,500 years old.

The Mysterious Colours Of Autumn Leaves

2008-04-12T01:53:00.001-07:00

Every autumn we look in melancholy at the falling leaves. But before falling, the leaves get yellow and orange with shades of red. But why this diversity in the color of the fallen leaves? The undergraduate research project of Emily Habinck at the University of North Carolina at Charlotte, revealed that the color of the autumn leaf was connected to the amount of nutrients in the soil. She found that on a North Carolina
floodplain with a soil abundant in nitrate (a nutrient that delivers nitrogen to the plants), yellow was the dominant color in the autumn "carpet", while the hillside, with poorer soils, were dominated by red during the fall. Even trees with typical red autumn leaves had even redder hues on poorer soils. A 2006 research led by William Hoch, a plant physiologist at Montana State University, connected the synthesis of anthocyanin red pigments in leaves to fall sunlight. "It wasn't until I read his paper that it became a full story," Habinck said. Leaves change color in the fall when trees stop the photosynthesis while withdrawing their nutrients from the leaves to be stored into their roots. "[The tree] pulls as many of these in as it can, then tries to drop just a skeleton of a leaf when it's done", Hoch told National Geographic. But the food withdrawal is not a rapid process, and in the meantime, leaves are left vulnerable to harmful light waves. "Anthocyanins protect leaves by "shading" them from excessive sunlight during the plant's relatively vulnerable autumn season," Hoch explained.Plants genetically engineered not to synthesize anthocyanins could not withdraw as many nutrients from their leaves. "So the bottom line is that the plants that were able to produce red pigments were able to squeeze more of the nutrients out of their leaves than the ones that couldn't. Thus, plants living in nutrient-poor soils benefit more from anthocyanin than those living on better soils.", said Hoch. "Scientists only recently made these connections, because when most other leaf-peepers are taking their fall-color tours, biologists are busy with academics. Most people's field season is in the summer," said Habinck.

The Mysterious Language Of Fish

2008-04-04T09:54:00.000-07:00

Fish don’t think/’Cause fish know everything." If we make scuba diving, the sea seems a world of silence. But it’s a deceptive view. Fish are not that smart and …they do speak. In fact, water transmits sounds better than the air and while light penetrates just to 300 m (1,000 ft), below this depth there’s total darkness and the inhabitants of the depths use sounds to ..."keep in touch". Abyssal fish employ sounds for echolocation, in order to detect the relief of the bottom. Amongst the sea dwellers, people are familiar with the song of the whales, that can be "heard" to 80 km (50 mi) away and the humpback
whales for example can sing at intervals of 20 minutes for hours. Cetaceans (whales and dolphins) are also known for their ultrasound echolocation: they emit sounds at 150 kHz that propagate till 3 km (1.6 mi) away, but which cannot be heard by the human ear. In fact, ultra-sensitive submarine microphones can record, in the sea water, rustles, cracks, gasps, gnashes, bangs, sizzles, drumming sounds, ship whistles, croaks, snores. Researches revealed how fishes produce sounds. By gnashing the front teeth emit sounds the seabreams (Sparidae), pufferfishes (Tetraodontidae), porcupinefishes (Diodontidae), sunfishes (Molidae); mackerels (Scombridae) employ the pharyngeal teeth.
Triggerfishes (Balistes), sticklebacks (Gasterosteus), and surgeonfishes (Acanthurus) emit sounds by rubbing their spines. Clownfihes use their jawbones to emit their clacking sounds. Some fishes have muscles that produce vibrations by their contractions. These muscles can be found on the walls of the swim bladder, like in gurnards (Trigla), dories (Zeus), toadfishes (Batrachoididae), shark catfishes (Pangasiidae) or armored catfishes (Callichthyidae) (which emit chirp like sounds). Fish calls can have a social meaning (like in herrings) of "gathering", "danger", or "change direction", or can be territorial, like in clownfishes (Amphiprion).
Seahorses (Hippocampus) emit mating calls. Croaker males (Sciaena) make drumming-like calls to chase away rival males during the mating season. Similar drummings are emitted by the toadfishes (Opsanus). Gurnards scare off predators with their grumbling calls. Pisara (Moenkhausia) – a fish of just 12 cm (5 inch) from the Amazon – emits elephant-like roars, while curbinatas (Plagioscion), also from Amazon, produce shots-like sounds.

The Mystery Of Dolphin's Language

2008-04-01T01:51:00.000-07:00

It has already been known that each dolphin population has its own dialect or even "language", which cannot be understood by a "foreigner" dolphin, as it is learned. But a new research made by PhD candidate Liz Hawkins, from Southern Cross University's Whale Research Centre, in Lismore, revealed that the dolphin "speech" is much more sophisticated than previously believed.The three years research was made on bottlenose dolphins off the coast of Byron Bay, NSW (Australia). Focusing on the starting and final frequency of the sound and its length, Hawkins encountered 186 different
whistle types out of 1650 recorded, of which 20 were common. The whistles could be assigned into five classes based on tone, and they were all connected to certain behavior.Socializing dolphins mostly emitted flat-toned or rising-toned whistles. Traveling groups made "sine" whistles: "These could be advertising their pod to other pods. They could be talking to another pod and saying, 'We are over here ... do you want to join?'," said Hawkins.Resting dolphins emitted "concave" whistles, sounds that failed in pitch and get up again, while downward-toned whistles could not be linked to any particular behavior. One class of whistles was connected to feeding."They could be advertising they have found food, they could be advertising to other animals there is food there, or it could be referred to a particular type of feeding or a particular type of food", said Hawkins.Dolphins riding the waves of a boat often emitted a particular sound, while in early investigation made by Hawkins, on a dolphin population of Queensland's Moreton Island, encountered a particular whistle emitted by lone dolphins."That whistle could definitely mean: 'I'm here, where is everyone?'," said Hawkins. She warned that dolphins transmit "context-specific information"."A specialist in linguistics would not call this a language. They are wild animals and generally wild animals only make sounds or transmit information that is essential to their survival. It basically suggests their communication is a lot more complex than what was generally thought."

The Mystery Of The Tallest People In The World

2008-03-29T02:35:00.000-07:00

Africa is a continent of the extremes. And the cradle of humankind. This is where the shortest people, the pygmies, appeared and still live. Amongst those of pure blood, men have an average height of just 1.45 m (4.34 ft) and women of 1.33 m (4 ft)! But pygmies are not a dwarf variant of the Black Africans. Their heads look large compared to the rest of the body. But otherwise, they are perfectly proportioned (the dwarfs are deformed). They represent an ancient race and only the Khoi-San people (bushmen), now restricted to South Africa, are more ancient amongst current Homo sapiens races, who 50,000 years ago left Africa and reached New Guinea and Philippines, where nowadays pygmies
still live. But a biological law says that on tropics animals tend to have longer limbs than their counterparts living in areas with temperate/cold climate. Humans do not follow strictly biological rules, as they can shape their environment, but still, in Africa the tallest human race, with the longest limbs evolved. This is the so-called Sudan type of the typical African Blacks. Today, this African race in its more or less pure form lives mainly in the southern Sudan and surrounding areas, while in central/western Africa they are heavily mixed with Congo type (the common typical Black Africans, like Bantu tribes). In Ethiopia and Somalia, this race mixed intensively with a White one coming from southwestern Asia thousands of years ago. In the case of some Sudanese tribes, males can have an average height of 1.9 m (6 ft, 4in) (!), while women of 1.8 m (6 ft) (!). These people have slim but strong bodies, and their heads are more elongated than in the case of the typical African Blacks. In case of a mixed race, these huge heights may not be generally attained by the population. The most famous group and more racially preserved of the Sudanese race are the Nilotic tribes (they all originated on the Upper Nile area). The most famous are Maasai, Turkana, Samburu and Dinka, whose main occupation is animal husbandry. Ancient (and modern) Nubians, the Black Pharaohs, were also of Sudanese race. When the French met this race of giants (in Chad tribes), they called them "the beautiful race". The Surma tribe from southwestern Ethiopia is famous due to their women's habit of wearing lipplates. On the marshes of the White Nile the Dinka live, tribes of nomad shepherds, whose main occupation is cattle/goat husbandry. That's why they are constantly in search of rich pastures. Dinka people do not eat during daytime. In the evening, the family gathers around the fire to eat milk, fish, cooked water tubers, vegetables and rarely goat meat. Cattle are never sacrificed. The community is led by a chief who chooses the grazing places. Each family detains a great number of cattle and some goats. Because they move so much, people do not keep too many belongings: just some clay pots, mats, headkerchiefs employed by the women to cover their heads and spear employed by men for hunting. Children grow in groups and nobody is allowed to punish them. At the age of 6, boys start to accompany their father for learning husbandry and milking. For protection against the mosquito bites (that can spread malaria in these areas), Dinkas anoint their bodies with ash.

Mystery Revealed: Ulysees' Real Ithaca Has Been Found

2008-03-25T11:13:00.000-07:00

The story of the ancient Greek hero Ulysses (or Odysseus) inspired many books, theatrical plays and movies. His adventures in the ten years way back home, from the Trojan war to his queen, Penelope, even sparked a term: "odyssey". His proverbial cunning gave birth to the Trojan Horse (image), which defeated the Trojans after ten years of war. Over the centuries, scholars believed the lost kingdom of this Greek hero was the current island of Ithaki, as Homer, in the Iliad, attributes to Ulysses in the island of Ithaca.

But British researchers have proven that Ulysses’ realm was in fact on the peninsula of Kefalonia, not Ithaki. People were caught in a trap: Homer asserts that the island was the westernmost of the Ionian archipelago, and the westernmost island is really Kefalonia, which is also much bigger than Ithaca described by Homer. The research team compassed British businessman Robert Bittlestone, an amateur archaeologist, Cambridge classicist James Diggle, and University of Edinburgh geologist John Underhill. Based on core samples, sea depth surveys and satellite imaging, the team found that the Paliki peninsula, found on western Kefalonia, may have been an island 3,000 years ago, and the seismic activity may have filled a sea channel, binding it to Kefalonia. "Three millennia ago, in Homer’s Iron Age, this peninsula was an island. Landslides and rockfalls from earthquakes later filled in the gap between the two islands", commented the researchers. The team made extensive geological and geophysical investigations on the southern end of the isthmus between Kefalonia and Paliki where they drilled a 122-meter borehole. The geological tests were carried on based on geographic considerations. "The drill never hit bedrock but instead plunged through loose sediments, rockfall and landslide material, reaching well below sea level," they said.Landslides and rockfalls from earthquakes filled in the valley between Kefalonia and Paliki, thus disguising the ancient channel described by Homer in the Odyssey. The absence of bedrock and the presence of very young marine fossils in the reworked borehole sediments confirm that rockfalls and landslides could have filled in the ancient sea channel to create the isthmus between the once separate islands. In this case, Paliki matches Homer's description of Ithaca. "Unlike many historical speculations, our answer to the age-old mystery of Ithaca's location makes a prediction that can be tested by geological techniques," Bittlestone said. The team now hopes to find the city and palace of Odysseus.

Mysterious Human Sacrifices In China

2008-03-22T00:55:00.000-07:00

Human sacrifices have been made in almost any human civilization. China is no exception. Chinese archaeologists have unearthed two human skeletons from a tomb in Fengyang, China. The tomb dates from the Qin dynasty period (221 to 206 B.C.). This dynasty is the first to have unified China and this is where the western name of China (Chinese people call themselves Han) comes from. The tomb contained nine people thought to have been buried alive together with the corpses of the dead.
Digging also exposed bronze cooking vessels and chimes. The Qin dynasty is also famous for the army of terracotta warriors and horses. Fengyang is more known as the hometown of Emperor Zhu Yuanzhang (1328-1398), the Ming-dynasty founder who chased away the Mongols from China in 1368. The Mongols, nomadic steppe warriors from the north, had ruled China as the Yuan dynasty since the conquest of China by Genghis Kahn in 1271. Another tomb, even older, has been excavated in northwest China's Shaanxi Province, close to the Yellow River, dated to the Zhou Dynasty (1046 BC-221 BC).The archaeologists found four colored wooden tomb figures, about 80 centimeters tall, which can be 500 years older than the famous terracotta army. The figures were placed at the four corners of the tomb. The wooden tomb figures have rotted and turned into clay tomb figures and the researchers are now planning to recast them with plaster and reagent.Tomb figures had a human shape and were made of wood, earth, terracotta or stone, being buried with the dead in ancient times. When the human sacrifice was made people were buried alive together with the dead ones. The excavation work started in April 2005 on the tombs in the Liangdai village. The diggings have revealed a lot of precious cultural relics, including gold, copper and jade and iron wares.

Mystery Revealed: How Can Sea Mammals Hold Their Breath for Hours

2008-03-18T17:07:00.000-07:00

Try to hold your breath for more than 2-3 minutes, and those around you will have to call the ambulance. But the sperm whale can dive for more than one hour to depths greater than 1,200 meters (roughly 4,000 feet), with average dives of 45 minutes, to depths of 600-1,000 meters (1,968 to 3,280 feet). Elephant seals can spend up to two hours in depths over 1,500 meters (nearly 5,000 feet), but average dives last only 25-30 minutes, to depths of about 500 meters (1,640 feet). Cuvier's beaked whales dive to maximum depths of nearly 1,900 meters (about 6,230 feet) with a maximum duration of 85 minutes. The average foraging dive for Cuvier's beaked whale is to a depth of 1,070 meters (about 3,500 feet) with a duration of 58 minutes. And all these seals and whales do it without passing out because of the lack of oxygen. A new research, published in the journal "Proceedings of the Royal Society B", shows that the secret is found in the amounts of special oxygen-carrying proteins encountered in their brains. It has been thought for long that hypoxia (low oxygen) tolerance in sea mammals was due to their adaptations to increase oxygen transport to the brain. But, many researches showed that the oxygen amounts in their blood vessels dropped within minutes of diving.
"The kinds of level we were seeing in arterial blood would have caused us to black out under water", said lead author Terrie Williams , professor of ecology and evolutionary biology at the University of California, Santa Cruz.
The team investigated two newly found proteins, called neuroglobin and cytoglobin. They resemble hemoglobin, blood's iron-containing protein that transports oxygen, but these globins are encountered only in the brain. The researchers investigated levels of hemoglobin and brain globins in 16 mammal species, from land mammals (like bobcat and mountain lion) to shallow swimmers (like the bottlenose dolphin and California sea lion) and deep divers (like the pilot whale and Risso's dolphin). Generally, the brains of sea mammals had higher amounts of hemoglobin and brain globins than those of terrestrial mammals, pointing that these proteins were involved in diving. The shallow-swimming and highly energetic bottle-nose dolphins, sea lions and sea otters presented larger levels of brain globins than the deep-diving whales. "The agile swimmers need to shuttle oxygen quickly to the brain and so they rely on the brain globins rather than the hemoglobin. The more hemoglobin in the blood, the more viscous the blood becomes, making transport to the brain slower", said Williams. But the researchers were surprised to find that the bobcat, opposite to dog-related species like foxes and coyotes, presented high levels of the brain globins in their tissues. "Maybe it's not just breath-holding that stimulates these globins, but high levels of activity, such as sprinting", said Williams. The discovery could explain strokes and aging in humans; by increasing globin synthesis in humans, the brain could be protected from negative effects of disease and aging. "[The diving mammals] might be the group to look toward, because evolution and selective pressures would push them toward better protection", said Williams. It has recently been proved that bowhead whales could live up to 200 years and more. "What if you could do something that would keep your brain active for twice as long?" asked Williams.

The Mysterious Ancient Egyptian Civilization

2008-03-16T01:26:00.000-07:00

The fertile banks of the Nile River offered several annual crops, as many floodings the river produced. The farmers would eagerly wait for the flooding, because after the water's retreat, the fields remained covered with a thick layer of mud on which the crops grew rapidly. This condition boosted the existence of various independent agricultural settlements. But around 5,200 BC, the first pharaoh, Menes, unified by war all the populations inhabiting the lower valley of the Nile River. Menes founded the first Egyptian dynasty and, like all the succeeding pharaohs, he was considered a god. 2. The kings of the first Egyptian empire, called the Ancient Empire, built gigantic pyramid-shaped tombs. In its interior, the construction had a chamber where the mummified cadaver of the pharaoh was deposited, with a plethora of offerings: food, clothes, jewels, dishes, and other. To avoid the theft of these treasures and tomb's profanation, inside the pyramid the architects built a real labyrinth of false passages to confuse the thieves. It was calculated that for the building the pyramid of Kheops,the largest ever, 110.000 workers labored for 25 years.
It is the only one of the Seven Wonders of the Ancient World still standing, 138.8 m (455.2 ft) tall. 3. Accommodated Egyptian families lived in beautiful mansions built of adobe or stone, close to canals or the Nile itself. Each dwelling had one level and an inner courtyard with a pool with papyrus and lotus. Against the hot climate, the houses had small external openings, just some very small windows which, with the serene sky of Sahara, delivered enough light for the houses during the day. The entrance to the house had porches sustained by columns, reunion places for men at the sunset. But if the tombs were richly decorated with wall paintings and bas-reliefs, the houses were not.4. The tombs were the place were Egyptian art (painting, sculpture and jewelry) reached its highest. Tombs varied along the time. The first type were pyramids and mastabas (small buildings made of mud brick, rectangular in plan with sloping sides and a flat roof, leading to a well carved in the ground leading to the funerary chamber), then speos (rock cut chapels in rocky cliffs).The tombs were richly adorned with art works: sculptures in painted wood, stone or ceramic dishes, coffins with the dead person's effigy, wall paintings in vivid colors and stone reliefs. Still, Egyptian art varied very little along the centuries.5.The main Egyptian god was Amon Re, the king of all gods. The god Ra Harakti was represented with human body and falcon head. His daughter was Maat, the goddess of truth and justice. One important Egyptian symbol was that of the solar disk surrounded by the sacred snake. Crocodiles were sacred in the ancient Egypt, and they were even embalmed; large embalmed crocodiles were found in many tombs and sacred edifices. A sacred bird was the ibis.Egyptians used to embalm baboons, cats, dogs, falcons, mice (representing the hearts of the sinners, offered to Osiris, the god of death). Human mummies show that Egyptians used prostheses 3,000 years ago.6.Ancient Egyptians were physically very similar to the modern Egyptian peasants, called fellahs. Nobles, priests, and the pharaohs shaved their heads and wore various types of caps and wigs. Oppositely, villagers or artisans wore long hair and shaved their beards. Against the hot sun, Egyptians wore linen clothes. In time, linen use turned exclusive for some social classes and served as cast distinction.The Egyptian attire consisted generally from a short fabric skirt and a tunic reaching to the ankles. The costume was completed with various adornments. Egyptian women were famous for their make up: they used khol, a black dye for outlining the eyes, ocher powder to give a healthy color to the cheeks, and a vegetal red liquid, called hena, for smearing their hands. Their toiletries included very refined tools: depilating pincers, palettes for mixing the beauty products and ivory sticks for applying them over the skin. They used wigs too, adhered to the head with gold and gemstone diadems and from which bead strings and fine metal plates hung. Noble women possessed luxury jewelry, like wide pearl collars, lapis lazuli, or glass beads. 7. The Egyptians were feared for their war chariots. The Egyptian war chariot was driven by two horses and provided a very rapid deadly advance. The horse and chariot were introduced into Egypt during the 17th century BC during the invasion of the Hyksos, a Semitic tribe coming from Syria and Palestine. Along their history, Egyptians made long conquest or punishment expeditions into Palestine, Phoenicia, Minor Asia, and Black Africa (like Nubia), this way maintaining the border of the empire. Egyptian archers were very skilled also. Chariots were used by the pharaohs for hunting as well, like in the lion hunt. The hunt of the lion was reserved to pharaohs and nobles (today, lion is extinct in Egypt). 8. The Nile was the main communication route in Egypt. Egyptian ships had a large rectangular or square sail and, despite their size, they were of low draft, which allowed them to avoid sandbanks, and were controlled through rudders of large reed astern. In that place, the highest part of the ship, an awning, was raised for storing the transported goods and make shelter during the voyage. Fishing boats were made like bundles of entwined woody vines and their curved stern somehow resembled a lotus flower. They were driven with poles, and fish were usually harpooned in shallow waters. 9. Egypt was an agricultural state; all classes were involved in it. The pharaohs made norms and laws, nobles surveyed the field work, while the slaves made the seeding and harvesting. The Egyptians turned desert patches into croplands, irrigating them with the Nile’s water. This was realized through a complicated network of irrigation ditches and canals.

The Mystery Of Modern Acoustic in Ancient Greek Theatre Solved

2008-03-14T23:29:00.000-07:00

The ancient Greeks were placing the last few stones on the magnificent theater at Epidaurus in the fourth century B.C. In the ancient Greece, it was one of the wonders of its time.

Unwittingly, the ancient builders made a sophisticated acoustic filter that enabled audiences in the back row to hear music and voices with amazing clarity, thousands of years before modern acoustic could do this.

The ancient Greeks tried to replicate the Epidaurus’ design, but without much success.A team at the Georgia Institute of Technology have found the factor missed by the ancients while looking for reproducing of this acoustic marvel: its seats, not its slope, or the wind. The rows of limestone seats at Epidaurus made an efficient acoustics filter that eliminated low-frequency background noises like the murmur of the public and reflected the high-frequency noises of the actors off the seats and back toward the seated spectators. This way, the performer's voice was reaching the back rows of the theater. Some theories assumed that site’s wind, which blows primarily from the stage to the audience, would have been the cause, while others thought that masks could have acted as primitive loudspeakers or that the rhythm of Greek speech had something to do with it. There were also assumptions that the slope of the seat rows could have been implied in the acoustic. But acoustician and ultrasonics expert Nico Declercq suspected that the theater’s corrugated limestone structure was filtering the sound waves at certain frequencies. "When I first tackled this problem, I thought that the effect of the splendid acoustics was due to surface waves climbing the theater with almost no damping," Declercq said. "While the voices of the performers were being carried, I didn’t anticipate that the low frequencies of speech were also filtered out to some extent."But when his team tested with ultrasonic waves and numerical simulations of the theater’s acoustics, the researchers discovered that frequencies up to 500 Hz were retained while frequencies above 500 Hz were reflected, a similar effect to the ridged acoustics padding on walls of a parking garage."So, how did the audience hear the lower frequencies of an actor’s voice if they were being suppressed with other background low frequencies? There’s a simple answer," said Declercq. The human brain can figure out the missing frequencies through a phenomenon called virtual pitch which enables us to appreciate the incomplete sound coming from small loudspeakers (in a laptop or a telephone), even if the low (bass) frequencies are not emitted by a small speaker."The Greeks’ misunderstanding about the role the limestone seats played in Epidaurus’ acoustics likely kept them from being able to duplicate the effect. Later theaters included different bench and seat materials, including wood, which may have played a large role in the gradual abandonment of Epidaurus’ design over the years by the Greeks and Romans," said Declercq.

Which Are The Earth's Eras? From Precambrian To Holocene

2008-03-12T03:32:00.001-07:00

In the 19th century, scientists discovered that the rocks with fossils are deposited in a defined stratigraphical order, an this is how Paleontology emerged. Already in 1761, Giovanni Arduino saw that the rocks could be assigned to ages: Primary, Secondary, and Tertiary. In 1829, J. Desnoyers added the Quaternary.Today, this is the classification of the geological epochs: A. Precambrian is the oldest eon, stretching from the Earth's emergence (4.5 billion years ago) till Cambrian (542 million of years ago). This is the epoch when life appeared, and the oldest traces of organic carbon seem to be 3.8 billion years old. During the Proterozoic eon (1 billion years ago-542 million years ago) the oxygen starts to accumulate in the atmosphere at the levels we know today. When the first fossils of complex animals appeared, the Cambrian started. B. Phanerozoic. Everything that followed the Precambrian till today is called the Phanerozoic, when complex life exploded on Earth. I. The Paleozoic Era (The Primary Era) ("ancient life") lasted from 541 to 251 million years ago.1. Cambrian (542-488 million years ago) takes its name from old mountains found in Wales, which formed during this period. Most phyla of current animals appeared in this period, but the fauna of the Cambrian was a heavy shelled and also very static one, dominated by trilobites, worms, shelled mollusks and echinoderms.2. Ordovician (490-440 million years ago) – named after the Welsh tribe of Ordovices. The climate was warm and there was a huge southern continent, Gondwana. The first coral reefs appeared in this period. The fauna was dominated by trilobites, brachiopods, sponges, sea lilies, shelled cephalopods. A mass extinction occurred at the end of this age, when 60 % of the species disappeared. 3. Silurian (440-416 million years ago) – named after the Silures, an ancient Welsh tribe. The climate was warm. The fist jawed fish appeared, and seas were dominated by giant sea scorpions, now extinct. Leeches, too, appeared in this period, but also the first terrestrial animals ever, primitive spiders and millipedes. The first vascular plants started the conquest of the ground .Fungi grew as big as trees.
4. Devonian (416-359 million years ago) takes its name from Devon, England. This is when fish developed legs and evolved to land tetrapods around 365 Ma; the first insects also appeared and real spiders colonized terrestrial habitats.The first seed-bearing plants formed huge forests. Primitive sharks started to dominate the ocean. The first ammonites, shelled mollusks that later evolved in squids and octopuses, appeared in this period. The land was made by Gondwana to the south, the continent of Siberia to the north, and the Euramerica in the middle. A mass extinction occurred at the end of this era. 5. Carboniferous (359-300 Ma) means "carrying carbon" as huge deposits of high quality carbon formed in this period, revealing a wet, hot climate that favored the forests' expansion. Oxygen in the air was at a higher level than it is now, 36 %, and there were huge insects, such as 3 ft (1m) wingspan dragonflies. Most primitive insect groups still living emerged in that period. Snails too went to the ground. The amphibians' diversity boomed and the first reptiles appeared. 6. Permian (300 to 250 Ma) takes its name from Perm, a Russian region close to the Ural mountains. The Earth experienced an Ice Age. Ferns were highly diversified, and gymnosperm trees, like ginkgos and cycads appeared in this period. Beetles and flies appeared. The land was dominated by mammal-like reptiles. A huge mass extinction occurred at the end of the Permian, when up to 95 % of the species went extinct. II. Mezozoic ("middle life", Secondary era) era spanned from 250 to 65 Ma. 1. Triassic (250-200 Ma) is named so because there are three specific stratigraphical layers coming from this era. Triassic was hot and dry, with no Ice Ages. Many types of huge marine reptiles evolved now. The flora was dominated by gymnosperms and seed-ferns. Mammals, turtles, crocodiles and the first dinosaurs appeared now. The first flying reptiles, pterosaurs, emerged in Triassic. Triassic ended with a mass extinction. 2. Jurassic (200-145 Ma) takes its name from Jura mountains (Germany). This is when Teleostei, the modern bony fish appeared (they form now most of the fish species, from trout to tuna). The land fauna was dominated by the huge herbivorous dinosaurs named sauropods, the largest beasts that ever roamed the Earth (the typical long-necked, long-tailed, small-headed, elephant-footed dinosaurs). Huge carnivorous dinosaurs preyed on them. There are also stegosaurs (plated dinosaurs). Birds appeared in this period from carnivorous dinosaurs. 3. Cretaceous (145-65 Ma), the "chalk era", named so because of the huge chalk deposits formed in this period. It was wetter but cooler than the Jurassic period. The continents started to split towards their current configuration. Angiosperms appeared and spread rapidly, co-evolving with the bees. Insects and fish were mainly the same as they are today. First marsupials and placentals were found. Birds were toothed. The main herbivorous dinosaurs were the horned, duck-billed and armored ones. The carnivorous ones were highly diversified and evolved. At the end of the Cretaceous a mass event wiped out the dinosaurs and most reptiles. 50% of the species and 25 % of the known families disappeared. III. Cenozoic started with the demise of the dinosaurs and it still continues today. 1. Paleogene (65-23 Ma) when small mammals evolved to the high diversity we know today. Many groups died without descendants. Birds and snakes, too, diversified greatly. The clime was somehow cooler. The Paleogene period was made of three epochs: Paleocene, Eocene, Oligocene. 2. Neogene (23-2 Ma) was dominated by megafauna. Most families, genera and even species we know today appeared in this period. The dawn of the human evolution can be traced now. There are two epochs: Miocene and Pliocene. 3. Quaternary started about 1.8 Ma. It’s the era of the last Ice Ages. There were alternations between cold Ice Ages and warm inter-glacials. It has two epochs: Pleistocene and Holocene. At the beginning of the Holocene (the last interglacial in which we still are today), 10-8,000 years ago, many species of the megafauna disappeared worldwide (giant sloths, mastodons, mammoths, saber-toothed cats, glyptodonts, woolly rhinos) while other locally (like horses and camels in North America).

How Do Tornadoes Appear On Earth?

2008-03-09T23:52:00.001-07:00

The tornadoes are short and small storms, but the most violent of all types. They emerge and evolve over the inland continental areas. The best conditions of tornado formation appear when a cold air current chokes with a mass of wet warm air, giving birth to enormous dark clouds (called "cumulonimbus"). These clouds generate a thunder storm, in which the warmer air ascends, creating a powerful current. In the upper part of the storm, the strong winds starts rotating increasingly rapidly, forming a vortex. In the US, tornadoes are also called twisters, due to the funnel-shaped air whirls. The wind in the "funnels" has a speed of over 300 km per hour. The rapidest speed recorded inside a tornado was of 450 km (280 mi) per hour; it was measured in Wichita Falls, Texas, in 1958. The vortex rotates in increasingly tight spirals, raising speed and ascending to the clouds. Then, the tornado descends from the clouds, reaching the ground with great violence. The tornadoes last just about one hour, advancing on the ground with 10 km (6 mi) to 560 km (350 mi) per hour. The winds destroy anything on their way and raise also cars, trains, roofs and people in the air, with the dust that makes the tornado visible. The objects are "aspired" in the vortex and transformed into deadly projectiles and thrown back to the ground. The air pressure inside the tornado is low; the low pressure of the tornadoes and the high pressure of the building make the latter simply explode. In 1989, a tornado killed this way 1,300 people in Bangladesh. A tornado touches the ground on an area with a diameter of a few meters up to 1 km (0.6 mi) and it can move over a short distance or several kilometers. A tornado lasts usually several minutes, but stronger ones can last over one hour. A storm lasting several hours can generate more tornadoes over an extended area. The tornadoes rotate clockwise in the Southern Hemisphere and oppositely in the Northern Hemisphere, but some do not obey these rules. In tropical waters, water spouts appear. Even if included in the category of weak tornadoes, these water columns, with diameters up to 30 m (100 ft), represent a great danger for the vessels found on their way. Tornadoes produce enormous damages and the most powerful and frequent occur in temperate areas of US, western Europe, Japan, India, South Africa, Argentina and Australia. In the center of US, about 500-600 powerful tornadoes occur every year at the beginning of the spring, most of them concentrated in the Tornado Alley in Texas, Oklahoma, Kansas and Iowa. Tornadoes are hard to predict, but the largest tornadoes are detected using radars based on the Doppler effect. This is a top 10 deadliest tornadoes in the US history:1. March 1925 in Missouri, Illinois, Indiana 689 dead2. 9-19 February 1884 southern US 600 dead3. 2-6 April 1936 Mississippi, Georgia, South Carolina, Arkansas 419 dead, 1,800 wounded4. 3-4 April 1974 Alabama, Georgia, Ohio, Michigan, Wisconsin 350 dead5. 21-22 March 1952 Arkansas, Missouri, Alabama, Tennessee 343 dead, 1,400 wounded6. June 1953 Texas, Michigan, Ohio, New England 321 dead7. 7 May 1840 Natchez, Mississippi over 300 dead8. 11 April 1965 Indiana, Illinois, Ohio, Michigan, Wisconsin 271 dead, 5,000 wounded9. 21 March 1932 Alabama 268 dead, 1,000 wounded 10. May 1987 Texas the destruction of the city Saragosa .

The Mystery Of Sun's Corona Deepens Even Further

2008-03-08T00:21:00.000-08:00

While being the most massive object in the solar system, the Sun may also hide one of the biggest mysteries in the solar system. The Sun is an average-sized main sequence star about 5 billion years old, currently in its mid-life, with a surface temperature approximated at about 6,000 degrees Celsius. Much of the light coming from the Sun is actually not emitted by the surface, but by the Corona, its outer gaseous layer dominated by powerful magnetic fields.
Something extremely strange is taking place within the Sun's corona. While the surface temperature reaches only 6,000 degrees, the Corona can experience more than 1,8 million degrees Celsius, 200 to 300 times hotter. This particular observation has been subject of great debate during the last few decades, strongly questioning our capabilities of predicting solar weather and the knowledge behind the nuclear fusion reactors.In an eager attempt to solve the mystery, American astrophysicists proposed that the super-heated Corona is generated by interactions with high-energy Alfén waves, and claimed to have detected these waves in the high atmosphere of the Sun. Alfvén waves have a corkscrew motion along the magnetic fields occurring in the Corona, while exceeding supersonic velocities.But, skeptics think otherwise. In a study previously proposed by researchers from the University of Warwick, they have revealed that the Corona contains magneto-acoustic Kink waves, a type of complex magnetic fields that usually occur in the outer layers of the Sun.Dr. Tom Van Doorsselaere, one of the participants in the study conducted by the University of Warwick, argues that the mistake made by the American team is understandable, however the data clearly shows that there are certain differences between Alfvén waves and Kink waves. Although they think that they are viewing Alfvén waves, they are in fact observing Kink waves.Doorsselaere describes Kink waves as a slight bend in the magnetic field of the Sun, such as those of a stressed string. This means that the study conducted by the Boulder Colorado last year has no validity, thus all calculations are wrong and astrophysicists still have no idea what makes the Sun's Corona such a hot structure.

Scientists Present New Theory For Earth's Iron Core

2008-03-05T08:24:00.001-08:00

Earth, like all planets in the solar system, has an inner most core, in the shape of a sphere measuring about 1,200 kilometers, consisting of a solid mass of iron, responsible for generating our planet's powerful magnetic field. Nonetheless, while implying measurements of its structure with the help of seismic waves, scientists have proven that they travel with great speeds in certain directions. For example, seismic waves seem to have greater speeds in a direction parallel to the plane of Earth rotation axis, rather than in a direction parallel to the Equator, as previously thought.It is mostly believed that while considering the extreme temperature of the Earth's
inner core, seismic waves should in fact travel at the same speed, regardless of the direction. A new theory presented in 2003, explaining what really happens in the Earth's core, in order to determine such behavior, has just been confirmed today through the use of computer simulations.Swedish researchers, from the Uppsala University, argue that the difference between direction-dependent speed rates, equal to about 12 percent, is determined by a body-centered cubic crystal structure which experiences high degrees of symmetry and elastic anisotropy, properties that depend on direction, even though it experiences extremely high temperatures. At the time of the publication, nearly five years ago, the theory was extremely hard to comprehend, mainly due to the fact that it was coming in direct contradiction with a series of crystalline structure theories.Nonetheless, no other crystalline structure could be modeled to account for the observed effect. Professor of condensed-matter, Börje Johansson, says that similar to the Earth's magnetic field is the heat balance that is in direct relation to the energy stored in the inner iron core, which in turn is dependent of the crystalline structure of the iron mass.By deriving models from the hexagonal structure of the iron core, scientist found that the most likely form of the iron crystal is a body-centered cubic crystal, with an inner atom right in the middle, and the long diagonal parallel to the planet's axis of rotation. The new theory also brings new insight in the stability of the magnetic field and the cooling rate of the planet's inner regions. The computer simulations used a density-functional theory, developed by Walter Kohn, Nobel Prize winner in 1999.

The Mystery Of The Maya Blue Solved

2008-03-02T01:08:00.001-08:00

A mysterious thick layer of blue pigment was often found at the bottom of many Maya sacrificial sinkholes, called cenotes. The Maya blue was employed for coloring offerings, pottery,
murals, and even the victims of ritual sacrifices. The chemical composition of the pigment has been known for long; also its resistance to age, acid, weathering and chemical solvents. "Unlike a lot of natural pigments that may fade, [Maya blue] is very stable," said Gary Feinman, curator of Mesoamerican anthropology at the Field Museum in Chicago, Illinois. But how the Maya got the pigment was not known. A new research published on the journal Antiquity and led by Feinman's team explains this. Lead author Dean Arnold of Wheaton College in Illinois noticed, on a pottery bowl from the Maya collection at the Field Museum, a wedge of incense with white flecks and the blue pigment. The bowl had been recovered at the beginning of the 20th century at the bottom of the Sacred Cenote at the ancient Mayan city of Chichén Itzá. That Cenote was dedicated to the rain god Chaak, and over 100 human sacrifices to that god were encountered in the sinkhole. The incense was copal, a tree sap commonly employed in Mesoamerica and whose smoke was thought to feed the gods. The white flecks were of a white clay mineral named palygorskite. Previous studies had shown that Maya blue was achieved through the fusion of palygorskite with pigments coming from the leaves of the indigo plant. But how, as the two ingredients do not readily react? Now, it appears that the copal was the secret. "Our study suggests that heat and copal incense likely were key elements used to fuse the two components together," Feinman said. Indigo, palygorskite, and copal (all connected to healing) were individually employed as drugs by the Mayans. "The offering of three healing elements thus fed Chaak and symbolically brought him into the ritual in the form a bright blue color that hopefully would bring rainfall and allow the corn to grow again," said Arnold. A 14-foot (4-m) layer of blue silt covered the bottom of the Sacred Cenote when first explored in 1904.

Earth's Identical Twin Only 4 Light-Years Away

2008-02-29T23:23:00.001-08:00

There are possibly millions of Earth-like planets lying out there in the immensity of the universe, each bearing just the proper conditions for the appearance and evolution of life, we just have to find them. Only a decade ago or so, the human race wasn't even capable of telling whether nearby stars, or any star in the universe for that matter ,bared any planet. The fact is that the first ever exoplanet was discovered in 1985, around a main sequence star ,however its detection wasn't confirmed until 1996.
Since then, more than 276 exoplanets have been discovered and confirmed, but none seems to have the characteristics of our planet. Gas giants, rocky planets ten times larger than the Earth. The problem is that the effects produced on a star by small planets such as our own are simply too low to be observed from great distances. Now astronomers claim to have evidence that there may be an Earth-like planet, or more, around the closest star to us, Alpha Centauri, a triple system about 4 light years away from Earth.Although on the night sky Alpha Centauri looks like a single bright star, as I said earlier, it is in fact a triple system formed of two Sun-like stars orbiting each other from a distance of about 23 astronomical units, part of the Population I of stars, meaning they have extremely high metallicity, a property shared by most stars that form in clouds of matter consisting of high amounts of dust, which is also a proper environment for the birth of protoplanetary disks and, possibly, planets.The usual technique for detecting the presence of a planet orbiting a star involves measuring the wobble of the star, induced by the gravitational pull of the planet. University of California researcher Javiera Guedes say that computer simulations have already shown in the past that there is a good chance that planets might have formed around one or both of the stars in the Alpha Centauri triple system. Her colleague, Greg Laughlin, from the University of California Santa Cruz, argues that, if the theory about planetary formation is correct, than there should definitely be at least a planet in that system.Even more intriguing is the fact that these planets have a high chance that they have conditions proper for the appearance of life. The simulations conducted by Guedes were mostly related to the smaller star, Alpha Centauri B, where Earth-like planets may form in the habitable zone of the system, and thus bear liquid water. There is no need for creating new detection methods, however the time required for such processes may span over the period of a few years.Most of the exoplanets found so far are gas giants, easy to understand why. Stellar wobble favors the detection of massive planets, as it depends on the gravitational field generated by the planet. Thus, greater gravitational pull basically means a greater chance to discover a new planet. Alpha Centauri B, on the other hand, is not just any star. It is the closest star to us, thus very bright. Further still, the detection of an Earth-like planet by measuring the wobble of the star is favored, because Alpha Centauri B is a relatively calm star, which would not interfere too much with the effects determined by the presence of a small planet.Its enhanced brightness can provide some of the most essential information related to the planet: whether it has or not an atmosphere, its chemical composition and many other characteristics.The study of the Alpha Centauri B star will be conducted by using the 1.5 meter telescope from the Cerro Tololo Inter-American Observatory in Chile, and will also include an evaluation of the natural oscillation of the star in order to create an image of their internal structure. Alpha Centauri B skeptic researcher Sara Seager for the Massachusetts Institute of Technology, is not so convinced about the validity of the findings of the UC team, but she recognizes that the simulations related to the detection of the planet are quite impressive.

The Largest Biological Structure On Earth

2008-02-26T23:14:00.001-08:00

The coral reefs form the largest biological structures on Earth. And the largest coral structure in the world is the Great Coral Barrier off the shore of northeastern Australia (parallel to the Queensland's shore),
located in the Coral Sea: it is 2,010 km (1,200 mi) long and 2 to 150 km (1.2-92 mi) wide, which would cover the surface of Norway. This is a tropical paradise with sunny islands, turquoise seas and gorgeous coral gardens. It is also the most biologically diverse reef and marine ecosystem in the world. Only in an islet, researchers found 100 species of corals, 700 of fish (imagine this is five times more than the number of fish species encountered in the European rivers!), 25 species of sea cucumbers, 34 species of cone-shelled snails. This without mentioning the sea turtles and sea birds. Overall, the Great Barrier Reef has 1,464 fish species (this means 10 % of the fish species found in the oceans), 405 species of reef forming corals (50 % of all known species), 1,000 species of sponges (20 % of the known species), 4,000 species of mollusks, 500 species of birds and 150 species of echinoderms. The Great Barrier is a succession of about 2,500 individual reefs of various type: platform, external and coastal, all forming a protective shield for the shore against the oceanic waves. Not all the islands of the barrier are coral-made. Some have a continental origin, being hill tops isolated from the mainland because of the rise of the sea level or the descend of the coast by about 100 m (330 ft). The Murray Islands represents the tops of three inactive volcanoes. The system of reefs and islands stretches from the Gulf of Papua (New Guinea) to the Lady Elliot island, south of the Capricorn Tropic. The continental platform in the barrier's area is 30-250 km (19-150 mi) wide and only 30-60 m (100-200 ft) deep, favoring the development of the reefs. The Great Coral Barrier is very young: it emerged about 15,000 years ago, at the end of the last glaciation, when the sea level rose, the water flooded what was then dry land. Australian Aborigines inhabited Australia before the existence of the Great Coral Barrier. Asian traders could have visited the area before the Europeans, in search of trepang (a highly sought sea cucumber). Today, the Great Coral Barrier is exploited for tourism, sea shells, corals and exotic fish. Resorts are found on the Gold Coast and Sunshine Coast. Over 500,000 tourists visit the area annually, mainly from May to December (during the dry season), avoiding the wet summers when the monsoons trigger cyclones.In 1983, the whole area of 350,000 square km (140,000 square mi) was declared National Park. Still, the Great Coral Barrier is menaced by global warming and contamination, being exposed to coral bleaching in the next 50 years.

The Mystery Of The Universal Deluge

2008-02-24T14:12:00.001-08:00

The Bible tells us about the universal deluge, whose unique survivors were Noah and his arch in which he had loaded a pair of each animal species of the Earth. After 150 years of drifting, Noah landed on the Mount Ararat and life turned back to normal. The echoes of catastrophic deluges were found in many civilizations. The ancient Greeks described three deluges: one during the time of Ogyges, other one during the time of Deukalion and the last during Dardanus, an ancestor of the Troy.
Curiously, the latter two kings may have really witnessed deluges. Oceanologists
found evidences that, 10,000 years ago, the Black Sea may had really experienced a catastrophic deluge. 18,000 years ago, during the last glaciation, the Black Sea was not a brackish sea, but an enormous freshwater lake. But at the end of the last Ice Age, 9,500 years ago, the melting of the glaciers raised the ocean level by around 100 m (330 ft) and with this the level of the Mediterranean Sea as well. At that time, the lake of the Black Sea had its level 150 m (500 ft) below the Mediterranean. The two seas were separated just by a weak barrier, and when this one gave up, the water of the Mediterranean gushed into the basin of the Black Sea in a flow four times greater than that of the Niagara, flooding 100,000 square km (40,000 square mi). The catastrophic event could be heard on a range of 100 km (62 mi). Of course, the rumor of this phenomenon spread from Asia Minor (Turkey today) to the whole Middle East, including to the ancient Hebrews. The first evidence of the deluge was found 15 years ago on the Ukrainian shores of the Black Sea. 140 m (480 ft) layers of clay and gravel presented traces of erosion, thus the place had once been the mouth of a river. In the same place, the researchers found fossils of freshwater snails and terrestrial plant roots, confirming the hypothesis of a freshwater lake. Drills made between 50-120 m (160-400 ft) revealed the presence of a large amount of cockle fossils (Cardium edule), bivalves common in the Mediterranean. If the Mediterranean had slowly flowed into the Black Sea, as previously thought, the sediments would slowly have deposited, so the mollusks from deeper depths should have been older than those of the upper layers. But the C14 analysis showed that they all had the same age, pointing to the hypothesis of a rapid and violent flood. The researchers believe the deluge had positive effects: it chased away the Neolithic farmers and shepherds from the shores of a freshwater lake and the survivors had to relocate, spreading agriculture – emerged into the Middle East – into the European and Caucasus areas: Romania and Georgia-Armenia. From Romania, along the Danube and its tributaries, agriculture could have spread into Austria, Germany, Czech area and Poland.

The Mysterious Polar Aurorae

2008-02-23T01:01:00.000-08:00

Polar lights (aurorae) have been described since Antiquity. Aristotle and Pliny wrote about the fear triggered by the arctic aurora, which people thought to forecast great adversities. Often,
these red lights were taken as coming from a large fire. During the Roman emperor Tiberius, Roman cohorts run to save the Ostia fortress, believing it was burning. During the 18th century, Danish guards of Copenhagen took an Arctic Aurora as the sign the city was in flames and triggered the alarm. The polar aurorae are produced by the impact of electrons emitted by the Sun with the atmosphere of the Earth, rarefied at high latitudes. Colliding with the atoms in the atmosphere, the solar electrons emit energy translated through polar lights. The phenomenon occurs at the two poles because the magnetism of the Earth deviates the flow of the electrons came from the Sun, attracting them along the terrestrial magnetic field towards a pole or another. The polar lights appear mostly in two forms. One type appears like wide rainbow arches, that last at the horizon for hours and even days. The second type is much more spectacular through the variety of shapes and color intensities. The most frequent of these aurorae appear like curtains floating in the atmosphere. They look crumbled on the edges but their colors are extremely beautiful.
They appear like drags of brown light, over which raises a curtain of violet clouds, thin enough for the stars to be seen through it. The center is always a bright yellowish, which grows continuously, like a rainbow. The edges appear like reddish and greenish stripes. They unfold like multicolor flags, fluttering like blown by the wind. The bunches of colors move from one place to another until they resemble large pyrotechnic fires. The colors are extremely varied and change at the same time. Various hues of red, orange, yellow and green mix. The sky appears like a fire cupola whose lights agitate like sea waves. The color intensities change like in a sunset. When the aurora starts to shut off, the red color remains the last, blooding the sky.

The Mysteries Of Weather

2008-02-21T23:37:00.001-08:00

Meteorological systems are continuously moving air masses, with diameters of 150-4,000 km (92-2,500 mi). Some are 12-15 km (7.5-9.2 mi) deep, located in the troposphere (the lower layer of the atmosphere). Those that are 1-3 km (0.6-1.8 mi) deep are faster. The meteorological systems are defined by their variations in atmospheric pressure and surrounding winds. The main meteorological systems are anticyclones (regions of high pressure, in which the air movement is oriented downward) and cyclones (areas of low pressure, where the air masses rise). Clouds form where the air rises. That's why low pressure areas are connected to cloudy, rainy or stormy weather. Anticyclones have instable weather that lasts for several days. In the Northern Hemisphere, anticyclone winds blow in the direction of the clock hands, and in the Southern Hemisphere they have the opposite direction. On meteorological maps, anticyclones are marked through a series of concentric isobars (lines uniting regions with the same atmosphere pressures). In anticyclone area, a weak wind blows and the sky is serene. Without the clouds, the heat emanated by Earth's surface rises in the cosmic space, that's why the soil and the air above cool rapidly during the night. During the winter, this often brings the freezing or, in wet air, fog. The weak winds favor these phenomena. A stronger wind would mix the air, and the cooling at the ground level would rise higher. Anticyclones can form in cold areas inclusively. In these places the air is heavier, that's why the pressure close to the ground is higher. This type of anticyclones form during the winter in Central Canada and Siberia.They are usually narrow, no more than 3 km (1.9 mi). Around the tropics (20-30o N and S), huge anticyclones form. These air masses are deeper and more stable. Here, the air risen because of the hot tropical sun descends to the surface of the Earth because of the high atmospheric pressure. In these areas the hot deserts of the world, like Sahara, are located. From the tropical anticyclones, the trade winds blow to the Equator, and the western warm winds blow towards the Poles. West winds encounter the east winds blowing from the cold polar areas in a frontal area. Along these fronts the cyclones form. The cyclones bring unstable weather and storms over the central latitudes. The frontal zone is not a right line. Along the front, sinuosities can appear due to the cold winds blowing towards the Equator and hot winds blowing towards the Poles. These movements cause turbulences (twirling movements), whose effect is accentuated by the strong jet streams, winds blowing at the upper limit of the atmosphere. In depression areas, winds blow in opposite direction to the anticyclone winds: counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. On meteorological maps, depression zones are represented as concentric isobars, the atmosphere pressure being lower in the center. Warm air and cold air do not mix easily. Warm air advances as waves in a front and does not mix with the cold, dense air, but it raises over it. The warm air is replaced by cold air, forming the depression zone. The depression zone has two fronts: the warm front delimits the approaching warm air masses from the masses of cold air on the surface. Here, the warm air rises over the cold air. The water vapors in the rising air cool gradually, condensate and form clouds. Immediately after the warm front, the cold front is found. Along the cold front, the cold air penetrates under the warm air, making it rise. That's why the cold front is cloudy and rainy. The cold front moves more rapidly than the warm front, and when a cold front meets a warm front, the warm air is pushed above the cold air. The phenomenon is called occlusion. When the occlusion takes place, the decrease of the atmosphere pressure ceases soon. The emergence of a hazy cirrus cloud at high altitude usually forecasts a pressure drop. Subsequently, a thicker cloud will emerge at an average altitude; this is an altostratus cloud. At a lower altitude, a rain cloud (nimbostratus) appears. These clouds bring a persistent rain, of several hours, before the passing of a warm front. Following a hot front, the warmth comes in a cloudy, humid zone. They are followed by the cold front, bringing showers, because of the ascend of the air masses. Along a cold front, abundant rains are frequent, but they do not last much, like those from the warm front. After the passing of the cold front, weather is serene and cool. Except the polar areas, storms can be found everywhere in the world. Annually, about 2,000 storms occur around the Globe. Many storms form along the cold fronts, on the whirls of the rapidly ascending warm and wet air, forming dark storm clouds (cumulonimbus) that rise over the cold front and move with 30 km (19 mi) per hour. Because of the heat of the soil and of the inferior air layers, tropical storms are the most violent ones. In these areas, in just one day, 600 mm of water can fall. Storms caused by the heated soil can also form in the temperate areas during the hot summer days, especially in the later afternoon. Along the Equator, turbulent groups of clouds form when the heat and humidity rise in the upper layers. Sometimes, groups can join one another, getting away of the Equator and produce violent tropical cyclones, called hurricanes, typhoons or willy-willy, depending on the area. Hurricanes are much larger than normal storms. In fact, storms can be parts of the hurricanes. Their diameter can vary from 200 to 500 km (125-312 mi). The center is a quiet hotbed, with an ascendant atmospheric movement. In this area, the sky is serene and the air is calm. But around the hotbed, the air rises rapidly, aspiring humidity, and forming the extremely violent systems of clouds and whirls. The wind speed overcomes 119 km (75 mi) per hour, even reaching 300 km (190 mi) per hour. In 1970, a hurricane killed about 1 million people in Bangladesh and India (West Bengal). The tornadoes are smaller storms (their diameter is of several hundreds of meters) but the most destructive of all types of storms. In US, tornadoes are called also twisters, being funnel-shaped air whirls. The wind in the "funnels" has a speed of over 300 km per hour. The rapidest speed inside a tornado was of 450 km (280 mi) per hour; it was measured in Wichita Falls, Texas, in 1958. The tornadoes last just about one hour, advancing on the ground with a speed of 10 km (6 mi) to 560 km (350 mi) per hour. They produce enormous damages and are frequent in US and Australia. In the center of US, about 500-600 tornadoes occur annually.

The origin of the tornadoes is unknown. They are often accompanied by storms. The air pressure inside the tornado is low; the low pressure of the tornadoes and the high pressure of the building make the latter simply explode. In 1989, a tornado killed 1,300 people in Bangladesh. Air whirls are much rarer than tornadoes and can emerge even on sunny weather. The air rises and starts spinning around. Sometimes, it takes with it dust, straw, garbage which make it visible. In hot deserts, the air whirls raise sand. The most famous rain bringing wind is the monsoon. It is encountered in places where there are significant differences between the summer pressure and winter pressure, like in India. During the winter, an enormous anticyclone forms above the Asia. From this anticyclone, an east wind blows, determining a dry and relatively cool weather in India. During the spring, the land starts to heat and a huge air mass with low pressure develops over the Tibetan Plateau and Afghanistan. From the Indian Ocean, a wet air mass will enter this system of low pressure. These air currents will produce the southwest winds, which cause powerful rains in India each summer.

The Mysterious Lost World of Roraima

2008-02-20T02:16:00.000-08:00

The name Tepui ("house of gods") comes from the language of the Pemon Indians and refers to the table-top mountain encountered only in the Guayana highlands of northern South America. Tepuis are isolated mountains, rising abruptly from the rain forest or savanna,
and not forming chains, things that makes them have of a unique variety of endemic plant and animal species. Angel Falls, the world's tallest waterfall, originates in a tepui.Mount Roraima is the highest and most famous of the tepuis. It is found at the border between Venezuela, Brazil and Guyana (80% in Venezuela). It is the highest peak in Guyana, and it is located at 5°12'08N, 60°44'07W. Its highest point is at 2,810 m (8986 ft).The plateau of Roraima has 50 square km (20 square mi), a real natural labyrinth made of canyons and amphitheaters. The soil of the tepui is made mainly of quartzite, a tough, compact grindstone, deposed 1.7 billion years ago, in Precambrian, being one of the Earth's oldest rocks. Along the years, water dissolved sand particles, modeling stone blocks, like ruined castles or small towers blackened by likens. The Guyana shield has never been covered by waters. In the tepui, plants and animals had to adapt to extreme conditions and unfertile soil. During the rainy season, between January to March, large amounts of rainfall strip the rocks, increasing the volume of the waters of the Orinoco River. Even if placed in Equator, the temperature is relatively cold, with an annual average value of only 8 degrees C. Because of the poor soil, some plants are carnivorous, getting the required nitrogen and phosphorus this way. Many grow on a very acid pit. Generally, the tepui have an endemic array of species adapted to these conditions. During the Ice Ages, the tepui vegetation descended to the base of the tepui, while during the warm interglacial ascended back on the top of the tepui. The most typical flowers of the tepui are the yellow Stegolepis. In the caves of the tepui nests the Oilbird (Steatornis caripensis), also called guácharo, the only bird known to use echolocation (like bats), only that they do not use ultrasounds, but audible sounds. The tepui have a fauna of 1 m (3.3 ft) long earthworms, frog-eating shrews and caecilians (limbless worm-resembling amphibians). Caecilians are blind and use their large teeth for consuming insect larvae. The Pemon Indians live at the base of Roraima, in the Gran Sabana. The population of 12,000 lives from farming, hunting and little cattle raising, but also from tourism, being carriers and guides for those intending to discover Roraima.Arthur Conan Doyle was inspired for his "The Lost World" by Roraima to place his world of Iguanodons and pterosaurs.

The Mystery Of Stonehenge

2008-02-19T01:25:00.000-08:00

Stonehenge represents one of the most beautiful prehistoric places worldwide, located on the plain of Salisbury, about 130 km (80 mi) off London. Why was it raised there? The assembly was not formed just of the megaliths we see today, but it also comprised a circular fortification and an odd ring made of filled holes. The vertical and horizontal stones of Stonehenge look like having been made by a carpenter. The oldest stage of the Stonehenge assembly is represented by
a wooden large and rounded construction, surrounded by a circular groove. The remains of this fortification, built between 3,200-2,700 BC are still visible, despite erosion. The mound was about 2 m (6.6 ft) in height, 6 m (20 ft) in width and had a diameter of 98 m (327 ft). The central wood construction is hard to describe, as very little is left of it. The holes of the pylons suggest it could have had 30 m (100 ft) in diagonal and a straw roof. The main entrance was oriented southward. Stonehenge of those times had less an astronomical purpose and it was rather used for burials. The central building could have been a funerary chapel, depositing the corpses before incineration or before being put into the tombs. Between 2,700-2,200 BC, the 56 "Aubrey holes", placed in a circle, were dug. Many contain human remains, but they were caved before the ash resulting from incinerations was buried there. Thus, the holes could initially have had another purpose. One theory says the holes were used fro predicting moon eclipses. The date of the eclipses could be forecast, if 6 of the stones were placed in a certain manner on 6 of the holes, then moved around the circle in a hole annually. The most significant thing is the astronomical alignment of Stonehenge, confirmed by the fact that in a summer day the sun rises over the stone called Heel Stone. Others believe that the holes were used for ritual ceremonies of libations, consisting in tasting and then pouring full cups of wine, milk and other beverages, as a homage brought to the deities or the dead. The holes were after that sealed with the limestone of the area, to mark the place where a homage occurred. The stones were blue dolerite rocks, up to 80 tonnes, extracted from Preeli Hills, Pembrokshire, located 200 km (120 mi) away in Wales. 81 boulders, each with a weight of 50 tonnes, made of tough granite, were taken from Malborough, 35 km (22 mi) away. 30 were raised vertically, the others were used as floor. Today, only half of the stones have remained erected. The enigma is how the Neolithic people, living in small communities engaged in animal husbandry, gathering and hunting, had such handwork for raising such a large construction? The work would have necessitated hundreds of powerful men...A 2006 theory about the role played by the Stonehenge complex in ancient times was brought by Professor Timothy Darvill, Head of the Archaeology Group at Bournemouth University: he believes that the ancient monument was a source for healing and not a mortuary place, as previously thought. In December, during the winter solstice, ancient British people thought that the henge was ‘occupied’ by a prehistoric god similar to the Roman and Greek god of healing, medicine and disease, Apollo. Many ancient tombs around Stonehenge revealed that a good proportion of those buried presented illness, with many bone injuries. In 2007, archaeologists discovered, near Stonehenge, the largest Neolithic village ever found in Britain, over 25 house sites, at the Durrington Walls, less than two miles (3 km) from Stonehenge. The square huts, with flanks of 16 feet (5m) length, were situated in a small valley north of Stonehenge, leading down to the Avon River. You should retain that Stonehenge was not built by Celts! Celts entered Britain during the 8th century BC. Druids, a modern pagan religious order getting back to the tradition of British Celts' priests, gather at Stonehenge, exactly during the summer solstice, as they regard it as a spiritualism center. Ancient druids too used to gather at Stonehenge to make sacrifices and offerings.

The Mystery Of Zombie Venom Injection

2008-02-17T07:28:00.001-08:00

There's no Voodoo or tetrodoxin neurotoxin from pufferfish involved in this case. And these Zombies will surely die eaten alive. In a new research published in the "Journal of Experimental Biology", Israeli researchers have found how the parasitic jewel wasp manages, through a venom injected directly into a cockroach's brain, to eliminate the prey's free will. The wasp's toxins appeared to shut down octopamine, a chemical controlling the motivation for walking in the cockroach's brain.Devoid of control, the "zombie" roach can be herded by the parasitoid wasp into its subterranean nest, where a wasp egg is injected into its abdomen. The hatching larva will start to eat its living "meat can", which cannot react, from the inside out. "The whole thing takes about seven to eight days, during which the meat has to be fresh. If you kill a cockroach, it rots within a day." said
co-author and neurobiologist Frederic Libersat, of Ben-Gurion University of the Negev, in Be'ér Sheva, Israel. One month later a mature wasp emerges from the roach's mummy. Octopamine is a brain chemical that turns insects alert, making them move and accomplish demanding physical activities. "It serves the same functions as noradrenaline, which is involved in the fight-or-flight reaction ... in the vertebrate brain," said Libersat. The wasps were found to insert their venom into the roach's protocerebrum, the brain nucleus containing octopamine-secreting neurons. The team could reverse the venom's action: by injecting an octopamine-like chemical directly into the protocerebrum of the zombie roaches, the free will of the insects was significantly restored. "This helps us understand how movement is initiated in animals," said Libersat. There are many parasites changing the behavior of their hosts, but only these parasitoid wasps directly target the host's brain using toxins. For example, snails and ants parasited by worms start standing on the top of the leaves of grass. This way, the snails are eaten by birds continuing the life cycle of the worm, while the ants are swollen by cows, for their parasite life cycle. Also, fishes parasited by tapeworms swim to the water surface, so that they can be eaten by water birds, which also get infected, and so on.

New Aztec Pyramid Explains Many Mysteries

2008-02-15T00:20:00.000-08:00

The Aztecs founded their bloody empire around A.D. 1200, and their civilization lasted only 300 years, while their empire dominated the area only 100 years before falling under the sword of the conquistadors. Still, at its peak, the empire spread from central Mexico to Guatemala, and it was one of the most advanced civilizations of America, with cities as larger as those of contemporaneous Europe. An 800-year-old Aztec pyramid has recently been found in the middle of Mexico City, inside the larger Aztec pyramid called the Grand Temple, at the location of the Aztec city of Tlatelolco."If the age of the edifice is confirmed, the discovery could push back the age of Tlatelolco – as well as that of its nearby 'twin city' Tenochtitlán – by a century or more", said lead researcher Salvador Guilliem, of Mexico's National Institute of Anthropology and History. "The structure's construction suggests it could have been built as early as A.D. 1100 or 1200, at least a century earlier than historical accounts suggest the city was founded", he added.The work of his team is trying to solve many mysteries of the Grand Temple. "Until now we thought Tlatelolco's Grand Temple had seven phases of construction. Now we know that there are eight", Guilliem told National Geographic News. Ground-penetrating radar allowed the discovery of human remains and grave offerings, near the Grand Temple."We dug 2 meters [6.5 feet] and found an offering of green stones and five
skulls. The remains—belonging to four adults and a child—appear to have been positioned with heads turned toward the north and bodies to the south. We think this building corresponds to the military elite", he said. Aztec legends suggest that Tlatelolco was constructed around A.D. 1358, at the same time with Tenochtitlán, but recent researches have questioned this. "If true, the date of this pyramid fits with many other archaeological finds that reveal evidence of Aztec occupation earlier than the traditional dates", said Susan Gillespie, an anthropologist at the University of Florida. Archaeologists know little about the relationship between Tlatelolco, a large market province, and the Aztec capital, Tenochtitlán. "The new discovery could challenge the notion that Tenochtitlán was the dominant twin during the early, entangled development of the two Aztec provinces. There are vague traces in the historical sources that Tlatelolco may have been more powerful than Tenochtitlán in its early decades. If there was indeed a large pyramid in Tlatelolco in the Early Aztec period, given that no such find exists in Tenochtitlán, it may suggest that Tlatelolco was indeed the dominant city in their early years", said Michael Smith, an Aztec expert at Arizona State University. Guilliem's team is convinced that the newly found pyramid was a temple dedicated to Tezcatlipoca Black, the Aztec god of commerce. "Workers intentionally broke into the smaller pyramid in 1368 while building a subsequent phase. When they broke it, it is very probable that they deposited a deity that's likely to be Tezcatlipoca. They most likely deposited an offering to the deity [Tezcatlipoca Black], conducted a ceremony, [and] then closed it again", said Guilliem.

The Mystery Of The Great Sphinx

2008-02-12T23:37:00.001-08:00

The Great Sphinx of Giza is the largest monolith statue in the world. It is 73.5 m (241 ft) long, 6 m (20 ft) wide, and 20 m (65 ft) high and represent the oldest known monumental sculpture.
But its origins are still a subject of debate, as the statue seems to be much older than the Egyptian civilization. In the famous Egyptian Giza Valley, three pyramids captured the attention of the Egyptologists. They were built at close distance one from another, being placed on a line, but not on a straight one, as the third pyramid is deviated from the line determined by the other two. Looking on a sky map from around 10,500 BC, made on computer, researchers discovered the missing cue: the three pyramids and the Nile were the perfect mirror image of the Lion's Constellation. The three pyramids represented the three stars, placed in the same position, of which the third was less shiny, determining the Egyptians to build a third smaller pyramid, close to the Nile, representing the Milky Way. The Sphynx could have been built at Giza by a pre-Egyptian civilization around 10,500 BC, and the Egyptians could have taken from that civilization the map of the sky to raise the Giza pyramids around 2,000 BC. Initially, the Sphynx could have been built in a savanna and represented a lion, the figure of the constellation. Around 9,000 BC, the clime changed and the savanna turned gradually into the current desert. The lion's body was covered by sand and protected this way against the action of external agents, erosion being experienced only by the upper part of the monument. Thousands of years later, a pharaoh ordered the recarving of the head, this time representing not a lion head, bur his. This would explain the disproportion between the huge made body and the restored head, which dwindled and did not experience as much erosion as the body. Common theory says the Sphinx would have been built (or at least the face was of) by King Khafra, somewhere between 2520 BC and 2494 BC, or Khufu, his father and the builder of the largest pyramid ever. Still, much more puzzles are triggered by the Sphynx. Robert M. Schoch, making a facial analysis, showed the sphinx has a distinctive "African," "Nubian," or "Negroid" aspect (the face is one of a Black man), not real with Khafra's face. Some data points that during Khafra's rule, the Sphinx was already buried in sand.

The Mystery Of The Shiny Mayan Temples Revealed!

2008-02-12T01:01:00.000-08:00

Among the three great civilizations in America before its discovery by Columbus (Aztec, Inca and Maya), the Mayans from Central America were by far the most advanced, culturally and artistically. The Mayans were the sole people of the pre-Hispanic America who created a complex hieroglyphic writing, a counting system, and a calendar forecasting the minimal fixings, their astronomical knowledge overpassing that of the contemporaneous Europeans. The Mayans were also famous for their pyramidal temples,
up to 60 m (200 ft) tall. A new research published in the "Journal of Raman Spectroscopy" shows that the Mayans painted some of their temples with mica in order to make them shine in the sunlight. Mica traces have been found in paint samples coming from the Rosalila temple in Copán, Honduras. The temple was constructed in the 6th century A.D., and it was later "swallowed" by a giant pyramid built around it. "The covering of sparkling paint likely gave the sacred site a dazzling appearance. The mica pigment would have had a lustrous effect. Mica is used today in paints for that very purpose—to create a shimmering finish to the paint," lead author, Rosemary Goodall, a doctoral student in physical sciences at Australia's Queensland University of Technology, told National Geographic News. "The gleaming paint also appears to have been applied periodically, perhaps in honor of important anniversaries or ceremonial events," she added. The researchers investigated the red, green, and gray dyes painted over the stucco masks on the outer walls of the temple, using a new infrared analysis technique."The mica used in the paint likely came from beyond the Maya realm. It appears that mica was available in what is now Guatemala. [The Maya] would have had to trade for something like that. (This) gives us an insight into how people in the southern periphery [of the Maya realm] interacted with people in the more northern regions," said Goodall. The team believes that the mica was applied based on a religious schedule. "Mica has only been found on the Rosalila temple so far. The building was in use for one hundred years—we know that because [the Maya] dated the opening ceremony of the building, and they dated the closing ceremony. It was repainted somewhere between 15 and 20 times, but mica was only used, I estimate, in every fourth or fifth repainting. It's not on every layer. More than likely there was something very significant about when they used it, if it was only used infrequently," said Goodall. "The Maya had very regular calendar periods, so the next step is to look at the core [of the paint layers] and see if we can find out the frequency of [mica's] use, which may give us an indication of whether or not it was applied to celebrate one of these period endings, or to mark some significant date," she added. "I think that's a very interesting idea, because the Maya numerical system is a base-20 system, so their calendar is based on a 20-year period called a katun. We know from hieroglyphs that these katun endings, or these 20-year periods, were important times of ceremony in the life of the king. Obviously Rosalila would have been a very important place for Copán's royalty," Cynthia Robin, an anthropologist and Maya expert at Northwestern University in Illinois, told National Geographic News.

How To Study A Brain

2008-02-10T01:16:00.000-08:00

The human brain is composed of billions of cells, each a separate entity that communicates with others. The chemical interaction of those cells determines personality, controls behavior and encodes memory; but much remains to be understood. Researchers at the University of Illinois at Urbana-Champaign have developed tools for studying the chemistry of the brain, neuron by neuron. The analytical techniques can probe the spatial and temporal distribution of biologically important molecules, such as
vitamin E, and explore the chemical messengers behind thought, memory and emotion. By dismantling a slice of brain tissue into millions of single cell-size pieces, each of which can be interrogated by mass spectrometric imaging techniques, Sweedler's research group can perform cellular profiling, examine intercellular signaling, map the distribution of new neuropeptides, and follow the release of chemicals in an activity-dependent manner. Sweedler will describe the techniques and present new results at the 230th American Chemical Society national meeting in Washington, D.C. Using these techniques, Sweedler's group has already discovered multiple novel neuropeptides in a range of neuronal models from mollusks to mammals. "We work with sea slugs, whose simple brains contain 10,000 neurons; we work with insects possessing one million neurons; and we work with mice having 100 million neurons," said Sweedler, who also is a researcher at the Beckman Institute for Advanced Science and Technology. "Working with these model organisms allows us to examine the functioning of such basic operations as the neuronal control of behavior and long-term memory." Sweedler's group also developed an approach for looking at the distribution of smaller molecules in brain cells. In a paper accepted for publication in the Journal of the American Chemical Society, and posted on its Web site, they report the subcellular imaging of vitamin E in the sea slug Aplysia californica. The researchers utilized novel sampling protocols and single cell time-of-flight secondary ion mass spectrometry to identify and map the presence of vitamin E in the membranes of isolated neurons. "To our surprise, we found that vitamin E was not distributed uniformly in the neuronal membrane," Sweedler said. "Instead, vitamin E was concentrated in the neuron right where it extends to connect with other neurons." The subcellular localization of vitamin E, which had been impossible to obtain in the past, supports other work that suggested vitamin E performed an active role in transport mechanisms and cellular signaling of neurons. Co-authors of the paper are Sweedler, research scientists Jinju Lee and Stanislav Rubakhin, postdoctoral research associate John Jurchen and graduate student Eric Monroe.

Children With Three Biological Parents?

2008-02-08T00:33:00.000-08:00

Common knowledge says that a child has two parents. But what about three biological parents? A team at the Newcastle University has created human embryos containing DNA from two women and a man,
a technology that one day could be a therapy for couples, for getting kids free of genetic diseases. Still, these embryos are primarily produced by one man and one woman."We are not trying to alter genes, we're just trying to swap a small proportion of the bad ones for some good ones," co-author Patrick Chinnery, a professor of neurogenetics at Newcastle University, told National Geographic News. The skipped bad genes are those encountered in the mitochondria, organelles producing cell's energy, and encountered outside the nucleus in any cell, including the female egg. DNA is encountered only in the nucleus and mithocondria, but while nuclear DNA comes 50 % from the mother and 50 % from the mother, mithocondrial DNA comes 100 % from the mother as all mitochondria come from the mother. Mutations in the mitochondrial DNA cause severe conditions like muscular dystrophy, epilepsy, strokes, and mental retardation. The research team took the nucleus of embryos carrying defective mitochondria in the woman's egg and transplanted it into an nucleus-emptied egg donated from a second woman with healthy mitochondria. "Most of the genes that make you who you are are inside the nucleus. We're not going anywhere near that," said Chinnery, pointing that in fact the child had only 2 parents. 10 such embryos have been achieved, but they were allowed to develop only 5 days. "If successful, this research could give families who might otherwise have a bleak future a chance to avoid some very grave diseases," said Francoise Shenfield, a fertility expert with the European Society of Human Reproduction and Embryology. Such tests carried on mice in Japan led to healthy mice offspring, with corrected mitochondria genes. "Further tests to assess the safety and efficacy of the process are necessary before it can be offered as a potential treatment," said Shenfield.

Magnetic Reconnection Reveal Its Secrets

2008-02-04T17:06:00.001-08:00

Because plasma is mostly composed of charged particles, such as electrons and ions, which have a global neutral charge, it is able to generate powerful magnetic fields, a very important feature if you ask a nuclear physicist working on the design of a nuclear fusion reactor. However, all good things must also have bad aspects as well, and when it comes to plasma magnetic reconnection there are. Magnetic reconnection represents a phenomenon in which magnetic fields originating from different sources break up and connect to each other, while high amounts of energy are released.Magnetic reconnection can be routinely observed on the surface of the Sun,
during the release of energy in the form of solar flares, and on Earth during intense aurora activity. Magnetic reconnection is also one of the factors that prevents physicists from creating nuclear fusion reactors that have high-efficiency electric energy production capabilities. As you probably already known, nuclear fusion reactors use powerful magnetic fields to confine a hot plasma gas. In order to produce the magnetic fields, one must provide high quantities of electric energy. But, due to magnetic reconnection, usually a nuclear fusion reactor drains more power to generate the magnetic fields than it produces by nuclear fusion, mostly meaning its operation is useless. On the other hand, the ESA Cluster mission studying the magnetic reconnection phenomenon has recently revealed that the regions required to determine a magnetic reconnection must be much larger than predicted. The area where the magnetic reconnection process is initiated is called the 'electron diffusion region', which can span in an area measuring 2 to 10 kilometers, thus the chance that we may be able to study these regions in the near future is rather remote.Nonetheless, computer simulations may provide a partial explanation on the processes that take place during a magnetic reconnection event, in the electron diffusion regions. Five years ago, the satellites from the ESA Cluster program detected what seemed to be a turbulent plasma region in the Earth's magnetosheath, measuring a massive 3,000 kilometers in length. Although it is 300 times longer than previously predicted by theory and at least four times bigger that seen in computer simulations, the new simulations seem to correlate perfectly with the observations.ESA satellites are capable of making high-resolution images of magnetic and electric fields, however higher resolution observations on the electron diffusion regions are required, in order to make precise measurements. NASA will complement ESA's fleet of magnetic imaging satellites with a number of four other satellites in the year 2014, which will be able to conduct simultaneous measurements on the effects determined by the magnetic reconnection phenomenon.

The Mystery Of Blue Eyes

2008-02-01T00:37:00.001-08:00

Nature played with one of our ancestors, and it caused the blue eye color to appear; and now, women are in love with the blue eyes of Leonardo DiCaprio and men with those of Kristanna Loken. And that ancestor lived 6,000-10,000 years ago, as found by a research carried out at the University of Copenhagen. "Originally, we all had brown eyes. But a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a 'switch', which literally 'turned off' the ability to produce brown eyes ", said Professor Eiberg from the Department of Cellular and Molecular Medicine. The OCA2 gene encodes the P protein, which controls the synthesis of
melanin, the pigment protein that gives the color of our hair, eyes and skin. The mutation is found in the gene adjacent to OCA2 that controls the activity of OCA2 and does not turn off completely the OCA2. It just decreases its action of spurring melanin synthesis in the iris, so that the low amount of melanin in the iris appears as blue, and not brown. If the OCA2 gene had been silenced completely, the result would have been a total lack of melanin in hair, eyes or skin, a disease called albinism. In this case, the eyes would have been red, due to the blood vessels of the iris. Eye color variation from brown to green is caused by the variable amount of iris melanin, but blue eyes are correlated with a very low level of variation in the melanin levels of the eyes, strictly linked to one genetic variation. "From this we can conclude that all blue-eyed individuals are linked to the same ancestor. They have all inherited the same switch at exactly the same spot in their DNA," said Eiberg. Oppositely, brown eyes can be the result of a large variation in the DNA sector controlling the melanin synthesis. The team investigated mitochondrial DNA (coming always from the maternal line) from blue-eyed individuals coming from countries far from one another, such as Jordan, Denmark and Turkey. In 1996, the same team had detected that OCA2 was involved in the eye color. The mutation from brown eyes to blue eyes is another example of neuter mutation; like hair color or baldness, it does not impact the individual’s survival ability.

Telepathy Found In DNA!

2008-01-28T10:01:00.000-08:00

Telepathy sounds like something out of the freak show, or SF stories. But, this trait has been found to be displayed by the DNA molecules. DNA double helixes can recognize fitting sequences from a distance and then join together, without the implication of enzymes or other molecules. Researchers had not suspected that the DNA double helixes could sort themselves.The DNA helixes are chains of 4 joined nucleotide bases (A, T, C and G). But A binds
chemically only to T, and C to G. The DNA helixes have been tagged with fluorescent chemicals and placed in saltwater with no proteins or other chemicals that could influence the DNA behavior. The researchers noticed that DNA molecules with identical sequences of bases were twice more likely to gather together, than in the case of DNA molecules of different sequences. But what attracted the DNA stretches together were not the same factors keeping the double helixes together, as the nucleotide bases of the DNA double helixes are located inside the helix. The outer helix is made by highly electrically charged chains of sugars and phosphates, which have the same chemically structure in any DNA molecule. The telepathic DNA recognition works under laws of physics. The DNA double helixes work like corkscrews, and the bases that form a DNA strand make the corkscrew bend one way or the other. DNA with identical sequences form corkscrews "whose ridges and grooves match up," said researcher Sergey Leikin, a physical biochemist at the National Institute of Child Health and Human Development in Bethesda, Md. "The electrically charged chains of sugars and phosphates of double helixes of DNA cause the molecules to repel each other. However, identical DNA double helixes have matching curves, meaning they repel each other the least. This could help avoid errors in how DNA combines, errors that underpin cancer, aging and other health problems. Also, the proper shuffling of DNA is essential to sexual reproduction, as it helps ensure genetic diversity among offspring," explained Leikin.

The Youngest Planet Around Sun-Like Star

2008-01-25T01:48:00.000-08:00

Compared to the age of our own planet, the Earth, which is about 4.5 billion years old, the newly discovered exoplanet is a baby,
estimated to be somewhere between 8 to 10 million years old and orbiting a star very similar to the Sun. Expect no further resemblance to our solar system however, as the new exoplanet has a mass at least ten times that of the planet Jupiter, circling its sun once every 3.56 days.Located at a distance of about 180 light years away from Earth in the Hydrae constellation, TW Hydrae b has a orbit radius of only 4 percent of that of the Earth around the Sun. This it the youngest planet ever discovered, since the observation of the first exoplanet nearly twelve years ago, that revealed planets at least 100 million years old.TW Hydrae b is indeed extremely young, so young in fact that the protoplanetary disk circling the star hasn't been cleared up by forming planets yet, proving the predictions of the current theory regarding the planetary formation models that states that planets must be able to form in a period as short as 10 million years, before the stellar radiation and solar wind has time to dissipate the protoplanetary disk in order to inhibit the planet formation process.Furthermore, though evidence of young planets forming around young stars has been previously found, astronomers were not able to view the actual planet but only the trails of its passing through the massive gas and dust cloud, left behind as it scoops part of the material in its path around the star, such as clear lanes inside the protoplanetary disks.The new exoplanet was discovered by Johny Setiawan from the Max-Plank Institute for Astronomy in Germany, through a traditional method which involved detecting the wobble of the mother star, produced by the gravitational pull of the planet. Nevertheless, though it is a widely used detection method, sometimes it can lead to false discoveries suggesting that a planet is present in the near vicinity of the star, when, in fact, the effect in produced by another class of objects or phenomena.For example, in such a young solar system, the newly born star is incredibly active causing matter fluctuations in its atmosphere, that contributes to the appearance of parasite signals, which are greatly amplified further if the star is spinning around its axis.Young solar systems are especially important in astrophysics studies, as not all of the processes taking place during planetary formation are well known. Planets are thought to form in the protoplanetary disks spinning around new-born stars, thus, finding such planets inside such structures can provide with important information about how they actually form.

Mysterious Westerlund 2 Star Cluster

2008-01-24T14:34:00.000-08:00

Westerlund 2 is believed to be the youngest star cluster in the Milky Way, with an estimated age of about one to two million years. Is is located about 20,000 light years away from Earth in the general
direction of the Carina constellation. However, not much is known about this cluster due to the fact that it is surrounded by a massive thick dust and gas cloud that prevents optical observations. NASA's Chandra X-ray Observatory will have the mission to penetrate the heavy cloud to reveal the mysteries related to Westerlund 2.As you might expect, the large amount of material in the respective area of space gave birth to some of the heaviest and brightest stars ever observed. Except that, however, little is known about the system. On the other hand, infrared and X-ray wavelengths can penetrate through the most massive dust clouds, and could even create an image of the galaxy all the way to the galactic central core.Chandra recently produced one of the best pictures of the Westerlund 2 star cluster. You can see how the low energy X-ray emissions are represented in the optical spectrum by the color red, the medium energy X-ray in green and the high energy emissions in blue, revealing a high density population of stars shinning bright in the X-ray wavelength.The most massive of these stars is the binary system WR20a with an approximated mass of about 82, respectively 83 times that of the Sun and can be viewed in the image provided by Chandra, to the right, just under the core of the star cluster. The two stars are relatively young, absolutely massive and extremely unstable, ejecting high quantities of matter in the form of stellar winds which collide with each other and determine the emission of powerful X-ray radiation. Most of these emissions can be viewed from different perspectives due to the fast rotation of the binary system, which completes an orbit around each other every 3.7 days.

Is The Universe Really Expanding?

2008-01-19T01:15:00.001-08:00

Geza Dyuk, the director of Astronomy at the Adler Planetarium, says that the universe is indeed expanding. Incredibly, even the great German physicist Albert Einstein didn't know for
certain if the universe was expanding or contracting, at the time when he published his Theory of Relativity back in 1905. So, while working at the General Theory of Relativity, he considered the universe to be static, only to find out later that his own theory pointed towards a dynamic universe.Not that a static universe would not be stable, but such a state would be possible only for short periods of time before it would either expand or contract. The breakthrough came in 1929 when the famous American astronomer Edwin Hubble concluded, while observing a series of galaxies, that the universe is inflating. Not only that, but its expansion speed is growing exponentially. Ever since, all other observations confirmed that, except for a few galaxies in the Local Group, all other distant galaxies are receding away from us. The further a galaxy, the faster the speed. This is exactly what Einstein predicted in the Theory of General Relativity, the universe is continuously expanding, stretching matter, so that, in a distant future, there will be more space in relation to the matter in the universe. Over time, other observations piled the evidence that the universe is expanding. However, what determines such a process is currently unknown, whether there is not enough matter to keep the universe together or dark matter exerts a repulsion force towards the normal matter. The inability to understand the exact nature of inflation is affecting our view of the whole universe. Astrophysicists are still struggling into comprehending the Big Bang, the nature of space-time, and the ultimate fate of the universe, whether that will be a Big Rip or a Big Crunch.

The Mystery Of Snowflakes

2008-01-18T01:13:00.001-08:00

The different shapes and sizes of snowflakes have been eluding scientists and mathematicians ever since the 17th century. Though they exist in multiple shapes, one of the most mysterious aspects of the natural snowflake growing process is why don't they produce an even wider range of crystal types. For the first time a mathematician and computer scientist from UC Davis in collaboration with colleagues from the University of Wisconsin-Madison have developed a program in which a snowflake is being modeled by a computer desktop.
In 1611, Johannes Kepler during a study of the snowflake shape, that of the dendritic type, suggested that structure actually reflects the image of an underlying crystal. The new mathematical model constructed and implemented by Janko Grayner shows that though no two crystals are identical, they share many similar features.Usually, snowflakes developing in the Earth's atmosphere require a starting structure on which the nucleation process to take place. Water vapors floating through the air meet dust particles and condense on them. If the temperature is low enough than it will form a base crystal which will grow, as other water molecules are attached and detached from the base crystal. The computer simulation had to be able to point out that newly attached molecules to crystal take preferential places, such as the concavities in the crystal base.The same mathematical model provided an explanation related to the crystal variety. It seems that the basic crystal shape is greatly affected by multiple atmospheric factors, such as temperature and pressure, but water vapor density as well.A mathematical model of a snowflake crystal constructed molecule by molecule is basically impossible with the current computing power available. Grayner estimates that even with the final configuration of the computer program, it would still take about one full day for a typical desktop computer to process all the data and accurately recreate the three-dimensional image of a dendritic snowflake.The computer model is able to reproduce all the known snowflake shapes. However, as in nature, dendritic snowflake are relatively rare. Another snowflake type extremely rare and unstable in nature is that of the butterfly shape that appears in the form of three butterflies stuck together along a single central body. It seems that snowflakes involve extremely complex spacial structures, which usually form between two plates, features observed with the help of electron telescopes.

The Brain Area of Speech Understanding Located!!

2008-01-14T01:39:00.000-08:00

The complex human speech is perhaps the main trait that puts us apart from apes. For example, chimps have the same mental addition ability like humans, while speech allows humans counting and advanced calculations.Human speech have been linked to two brain nuclei controlling the language (articulating control, data storing and integration of the grammar rules), located in the left hemisphere of the cortex. What we want to say is initiated in an area of the left cortex called "Wernicke zone". This communicates
with "Broca zone", involved in grammatical rules. Impulses go from these areas to the muscles involved in speech. These zones are connected with the visual system (so we can read), auditory system (so we can hear what others say, understand and answer) and also have a memory bank for recalling valuable phrases. The left hemisphere is also the center of analytical thinking, linked to logical abilities. Now, a study published in the journal "Neuron" has detected the brain nuclei where speech sounds got their abstract meaning, rather than being perceived as a stream of sounds. This discovery shows that the human speech understanding goes beyond lower-level detection of speech sounds, requiring specialized sensory nuclei. To detect these areas, the team put the subjects to listen to a series of simple speech sounds, while looking at a video of people pronouncing the sounds. But, the speech sounds could either match the video or not. Through various combinations of speech sounds and videos, the team detected, by using fMRI imaging, the brain nuclei involved in abstract processing of the speech sounds, not just their sensory perception: two areas in the left-hemisphere's (this is not a surprise) speech related area, named pars opercularis and planum polare. "We have shown that there are neurophysiological substrates that code properties of an audiovisual utterance at a level of abstraction that corresponds to the speech category that is ‘heard,’ which can be independent of its sensory properties. We set out from the observation that there is no need to posit the existence of abstract coding to explain emergent features of audiovisual speech, because these features may just be the result of joint activity in lower-level unisensory regions. Yet, our results indicate that neural activity in left-hemisphere regions does indeed track the experienced speech percept, independent of its sensory properties", wrote the authors.

Which Are The Types Of Memory We Possess?

2008-01-09T08:29:00.000-08:00

Brain researches show that we do not have a sole memory and reveal that there are actually various types of memory, differentiated and complementary. The immediate memory lasts just miliseconds, and allows you to memorize rapidly things like a phone number or a name, for example. The working memory is a means of storing the information that is useful in a certain activity, like
the shopping list. The long-term memory makes it possible for a 100-year-old person to recall with all the details an episode in his/her childhood. The declarative memory means all the memories that can be recovered voluntary. The episodic history memory preserves all the happenings of the personal history. The semantic culture memory represents what remains recorded in the brain after forgetting things following a learning process. This happens after an exam, for example. In the end, culture is what persists after we have forgotten it all. The proceeding memory leads all the habits and automatic behaviors. For example, this allowed the Polish pianist Wladyslaw Spillzman (whose life was portrayed in the movie "The Pianist"), escaped from the Warsaw's ghetto, to remember without hesitations after 6 years the recording of a Chopin nocturne, interrupted by the German bombardments in 1939. Of course, the base of the memory is formed by sensations, olfactive, visual, gustative, tactile and auditory. The sensations reach the brain's emotional center, the amygdala. In the amygdala, the brain decides in a question of seconds the faith of the sensory information. Now the autobiographic and emotional meaning of a sensation is decided. The right half of the brain cortex stores the biographic memory, emotional recalls, autobiographic and time-related memories, like the first day of the high school or the 9/11 attack. The right half of the brain cortex stores the cognitive and factual memories (like Paris is the France's capital, words, numbers and so on). The cerebellum stores the memory involving movement, like playing guitar or swimming. The centers for positive recollections were detected in the center of the brain's cortex, while the center of the negative recollections is at the edge of the cortex.

The Dirty Image Of The Universe

2008-01-07T12:42:00.000-08:00

We mostly view the universe as a regular structure filled with matter and light in every direction, while in fact it is anything but that. The universe is a cosmic mess, with galaxies randomly placed
and linked together by filaments of matter some billions of light-years long. Forget about light! Only four percent of the matter in the universe is actually visible, meaning it is lit by light coming from the neighboring stars, including the stars themselves.It is currently believed that more than 85 percent of the whole mass of the universe is represented by intergalactic matter in the form of filaments linking galaxies together, consisting of dark matter. Dark matter is not actually dark, instead it is called that way because it hasn't been observed yet , although there are clear evidence that it exists.It is extremely hard to study the universe and understand the processes which take place in it, taking into consideration that more than 90 percent of it is invisible in the electromagnetic spectrum, used as a primarily tool to observe it. Astronomer Rodrigo Ibata from the Observatoire Astronomique de Strasbourg in France proposed that the cosmic filaments are some sort of mean to exchange matter throughout the universe, from a celestial body towards the other.In order to prove the existence of the predicted cosmic filaments and the exchange of matter between two large structures such as the galaxies, the ESA has scheduled the launch of the GAIA spacecraft the would make detailed measurements of the distances between more than a billion stars and their motions, to determine if intergalactic matter filaments are present in the vicinity of our galaxy. Ibata argues that such filaments may play a key role in the formation of galaxies.Nevertheless, even if instruments such as the GAIA spacecraft would be currently operational, we wouldn't be any farther from the point we were a month ago, since the massive amount of data the satellite would send back to Earth can't be efficiently processed with the computing technology these days. A second problem eventuality would be the question whether we could learn something new about the universe we live in or even comprehend the processed information.According to Claude-Andre Faucher-Giguere, one way of understanding the processed data would be to embark in a process of comparing it with observations made by astronomers, in order to conceive the best theoretical image of the universe.Most of the observations currently made in the visible universe are mostly made in the optical spectrum but have been lately extended to the whole electromagnetic spectrum, such as radio, infrared, ultraviolet, gamma ray, and x-ray wavelengths.

Where Is The Mysterious Dark Energy?

2008-01-06T14:43:00.000-08:00

The Universe is a mysterious place that we have only begun to study and it seems that every time scientists answer one cosmological question, a few more arise, making the complete understanding of the space we live in a distant possibility.Dark energy is one of the mysteries, as it is not only elusive, being theorized but never actually observed, but also a concept whose understanding seems closer with every new find yet never fully in our grasp. ‘What exactly is this dark energy?’ ‘What does it do?’ ‘How does form?’ are just some questions that astrophysicists are trying to answer but never seem to agree on.Modern views of this exotic form of energy present it as one that can permeate all the space and most likely caused an increase in the expansion rate of the Universe. At least that's what recent observations of the expansion seem to indicate.For now, two forms of this energy have been theorized, one being a cosmological constant, that apparently fills space homogeneously, and the other being represented
by scalar fields having an energy density that varies both in space and in time.One of the problems regarding this dark energy is the fact that, though it is believed to have a negative pressure, drawing in matter from its surroundings, it actually causes an expansion of the entire Universe. The idea of negative pressure is not something we can easily understand. While every substance has a positive pressure, like gases, liquids and even light, which push outward on their surroundings, dark energy pulls on its surroundings, like a solid stretches to support a hanging weight.It has been calculated that this negative pressure has a gravitational repulsive effect even greater that the gravitational attraction caused by the energy itself, thus overwhelming all other forms of gravitational attraction, which in turn produces the accelerating expansion of the universe.But how can pulling be causing a pushing effect? Well, both types of pressure being non-gravitational forces, they cause the movement of substances within space but never really change space itself. On the other hand, they cause a gravitational attraction or repulsion that acts on the fabric of space, decreasing and increasing the amount of space between substances, respectively.Since they act in opposite directions, this is what actually produced the current size of the Universe, so scientists say this energy must exist in order to reconcile the current measurements of the expanse of space with the calculated amount of matter in the Universe.But experiments have yet to observe this energy in action, since its small density makes it really hard to detect in laboratory. To give you an idea of this density, a space of 100 billion cubic kilometers made entirely of dark energy weighs just one thousandth of a gram. For comparison, the volume of the Earth is of a little more than 100 billion cubic kilometers.Where exactly can dark energy be found? Everywhere, yet nowhere. Some recent theories seem to have come up with interesting locations and probably the most intriguing one says that they cannot be found in our three-dimensional space.

Surprising Dinosaur Found In Antarctica

2008-01-06T01:23:00.001-08:00

Today, Antarctica is a frozen desert. But once, it was covered by a lush tropical vegetation and inhabited by heat-loving dinosaurs. A new research, published in the journal "Acta Palaeontologica Polonica", describes a large dinosaur that wandered across the Antarctica about 190 million years ago, during the early Jurassic period. A partial foot, leg and ankle bones of the extinct beast were found by a team of Augustana College, during the early 90's, on Mt. Kirkpatrick near the Beardmore Glacier, in Antarctica, at an elevation of over 13,000 ft (4,000 m), but the remains have only recently been examined. "The fossils were painstakingly removed from the ice and rock using jackhammers, rock saws and chisels under extremely difficult conditions over the course of two field seasons", said co-author Nathan Smith, a graduate student at The Field Museum, in Chicago.The 20-25 ft (6-8 m) long and 4 to 6 tons heavy dino was called Glacialisaurus hammeri,
it was a species of sauropodomorph, a dino branch including sauropods, the largest animals ever to walk the earth, like Diplodocus and Apatosaurus. The new species shows that sauropodomorphs had a wide distribution in the Early Jurassic, inhabiting places from China to South Africa, South America, North America, and (now) Antarctica. "This was probably due to the fact that major connections between the continents still existed at that time, and because climates were more equitable across latitudes than they are today", Smith said. By Early Jurassic, the southern landmasses (Antarctica, South America, Africa and Australia) were forming a sole continent, Gondwana. They started to split off during the mid-Jurassic, about 167 million years ago. The Glacialisaurus was discovered along with a possible sauropod, thus the earliest sauropods coexisted with the less evolved sauropodomorph relatives for a long period (it's like the Australopithecus would still be living with us). "They are important because they help to establish that primitive sauropodomorph dinosaurs were more broadly distributed than previously thought, and that they coexisted with their cousins, the true sauropods", Smith said. At the same site, researchers discovered a nearly complete skeleton of a theropod (meat eating) dinosaur, named Cryolophosaurus ellioti, pelvic bones from a possible sauropod, a pterosaur (dinosaur era flying reptiles) humerus bone, and the tooth of a large tritylodont (an extinct primitive type of mammal).

The Chilling Facts About Sunbathing

2008-01-05T09:14:00.000-08:00

Alarming new statistics from America on an epidemic of skin cancer could make Europeans think twice before sunbathing this summer. Skin cancer, which can be caused by spending too long lying in the sun, is now the most common type of cancer found in young American women aged 25 to 29 years old.

Researchers in the US have found that it is increasing by 5% a year all over the world and that causes have doubled in the last 10 years.

Britain does not have the exotic beaches of Florida and California, but the problem of skin cancer is just as serious because in recent years more and more people have been spending their holidays in hot countries. More than 1,000 people die from this form of skin cancer in Britain every year, and the majority of them are women.

Experts have discovered that the cancer can attack people 10 years or more after they have been exposed to the sun's rays. It is one of the hardest cancers to treat. Surgery can only deal with the problem if it is caught at an early stage.

US researchers have been trying to create vaccines which could enable the human body to destroy the cancerous cells . In the meantime, the health authorities in britain are trying to make people more aware of the dangers of sunbathing. The people most at risk include those with a large number of moles on their bodies; red-haired/ fair-haired people, blue eyes, fair skin and freckles; those who find it difficult to go brown and burn easily; and those with a history of the disease in two or more family members.

The Mystery Of The Carnivorous Plant's Killing Slime

2008-01-04T01:53:00.001-08:00

These are the most amazing carnivorous plants: the 117 pitcher plant species of the genus Nepenthes, found from Madagascar and southeastern Asia to northeastern Australia. They possess the most spectacular traps, even if considered amongst the least sophisticated functionally, till the publication of a new research in the journal PLoS ONE. Also called "Monkey cups" as the monkeys have been seen drinking rainwater from these plants, the pitchers are mainly epihytes, that's why they must hunt insects to get the necessary nitrogen. The leaf continues with a tendril than ends with the pitcher like trap. The trap has a fluid of the plant's own production, which may be watery or syrupy and is used to drown the prey. The lower part of the trap contains glands which absorb nutrients from captured prey. The upper inside of the trap has a slick waxy coating which impedes the escape of almost any prey. Around the entrance to the trap is a structure called the peristome (the "lip") which is slippery and often quite colorful, attracting prey but offering an unsure footing. Above the peristome there is a lid (the operculum): in many species this keeps rain from diluting the fluid within the pitcher, the underside of which may present nectar glands which attract prey.The Nepenthes trap can be 50 cm (20 inch) long and 15 cm (6 inch) wide, and the plants usually capture insects, even if larger species has been signaled, like rats or lizards. The fluid inside the pitcher was believed to act just like a digestive juice, but the new French research has revealed to act also on trapping the victims. High-speed videos made on Nepenthes rafflesiana of Borneo showed that flies attempting to escape the fluid got stuck rapidly, apparently tied by sticky filaments emerging from the juice, resembling elastic mucus fluids. "The elastic consistency of the plant fluid also makes it resemble quicksand. The quicker insects within the fluid move, the more trapped they become", said co-author Yoel Forterre, physicist at the University of Marseille."The only chance for insects to escape the fluid would be to move slowly. But once fallen in the pitchers, insects most often panic and exhibit quick movements.", said co-author Laurence Gaume, biologist at the University of Montpellier. The liquid was effective even when diluted at below 10 % with water, adapting to the abundant rainfall in the plant's habitat, and the juice could act this way in all Nepenthes species. Further investigation of the liquid could explain the behavior of similarly elastic liquids, like mucus and blood, the crawling of snails "or motion of spermatozoa in the female reproductive tract", Forterre added.But the researchers are intrigued by the fact that the pitchers harbor whole mini-communities, not affected by the liquid, like mosquitoes and midge larvae eating the debris accumulated in the pitchers and help to a more rapid breakdown of the captured prey. There is also a species of crab spider that can enter and get out of the pitcher at will, even stealing from the plant's victims. "It would be useful to carry out more fieldwork and lab observations to study how insects that live in this fluid manage," said Gaume.

Must-See Meteor Shower Friday Morning

2008-01-03T14:31:00.000-08:00

The Quadrantid meteor shower is due to reach maximum in the predawn hours of Friday, Jan. 4. The Quadrantids are notoriously unpredictable, but if any year promises a fine display, this could be it.
Indeed, this may end up being the best meteor shower of 2008.
The Quadrantid (pronounced KWA-dran-tid) meteor shower provides one of the most intense annual meteor displays, with a brief, sharp maximum lasting but a few hours. The timing of peak activity favors Western Europe and eastern North America. Weather permitting, skywatchers in rural locations could see one or two shooting stars every minute during the peak.
Annual challenge
Each year, many factors combine to make the peak of this display difficult to observe.
Peak intensity is exceedingly sharp: meteor rates exceed one-half of their highest value for only about 8-hours (compared to two days for the August Perseids). This means that the stream of particles that produce this shower is a narrow one – apparently derived within the last 500 years from a small comet.
As viewed from mid-northern latitudes, we have to get up before dawn to see the Quadrantids at their best. This is because the radiant – that part of the sky from where the meteors to emanate – is down low on the northern horizon until about midnight, rising slowly higher as the night progresses. The growing light of dawn ends meteor observing usually by around 7 a.m. So, if the "Quads" are to be seen at all, some part of that 8-hour active period must fall between 2 and 7 a.m.
In one out of every three years, bright moonlight spoils the view.
Over northern latitudes, early January often sees inclement/unsettled weather.
It is not surprising then, that the Quadrantids are not as well-known as some of the other annual meteor showers, but 2008 may prove to be an unusual exception.
Exception this year
According to the International Meteor Organization, maximum activity this year is expected on Friday 1:40 a.m. Eastern Standard Time.
For those in the eastern United States, the radiant will be about one-quarter of the way up in the east-northeast sky. The farther to the north and east you go, the higher in the sky the radiant will be. To the south and west the radiant will be lower and the meteors will be fewer.
From Western Europe, the radiant will soar high in the east as the peak arrives just as morning twilight intervenes.
Quadrantid meteors are described as bright and bluish with long silvery trains. Some years produce a mere handful, but for favorably placed observers, this could be a shower to remember; at greatest activity, Quadrantid rates will likely range from 30 to 60 per hour for eastern parts of the U.S. and Canada, to 60 to 120 per hour for Western Europe.
Across central and western parts of North America, the shower's sharp peak will have already passed and meteor activity will be rapidly diminishing by the time the radiant has a chance to get very high in the northeastern sky. Nonetheless, hourly rates of perhaps 15 to 30 may still be seen.
The moon will be a waning crescent, not rising until after 4 a.m. and will add very little light to the sky.
History and mystery
Adolphe Quetelet of Brussels Observatory discovered the shower in the 1830's, and shortly afterward it was noted by several other astronomers in Europe and America.
The meteors are named after the obsolete constellation Quadrans Muralis, the Mural or Wall Quadrant (an astronomical instrument), depicted in some 19th-century star atlases roughly midway between the end of the Handle of the Big Dipper and the quadrilateral of stars marking the head of the constellation Draco. (The International Astronomical Union phased out Quadrans Muralis in 1922.)
Meteor showers are generally caused by debris from comets. Most of the "shooting stars" result from bits the size of sand grains, which vaporize as they streak through Earth's atmosphere.
The parentage of the Quadrantids was long a mystery, however. Then Peter Jenniskens, an astronomer at the SETI Institute in Mountain View, Calif., noticed that the orbit of 2003 EH1 – a small asteroid discovered in March 2003 – ''falls snug in the shower.'' He believes that this 1.2-mile-wide (2 kilometers) chunk of rock is the source of the Quadrantids; possibly this asteroid is the burnt out core of the lost comet C/1490 Y1.

Shocking Discovery Above The Earth's Surface

2008-01-03T02:29:00.000-08:00

Talking about being in the right place at the right time, this is exactly what allowed ESA's Cluster spacecraft to make a startling discovery. The Cluster mission is an European Space Agency (ESA) unmanned space mission mission to study the Earth's magnetosphere using four identical spacecraft flying in a tetrahedral formation.What the spacecraft discovered amazed astronomers: a shock wave that kept breaking and reforming , a model predicted only in theory but never actually seen in space.

The shock wave is a natural phenomenon found above the Earth's surface, on the side facing the Sun, at 96,100 kilometers (59,700 miles), at around a quarter of the distance to the Moon and it's produced by the flow of electrically charged particles from the Sun entering Earth's magnetic field .As the particles collide with the magnetic field, they're rapidly slowed, causing a barrier of electrified gas, called the bow shock, to build up, much like water is pushed to the sides by the nose of a boat.The reforming of this wave was theorized 20 years ago, but it's the first time it was recorded. The recording was made as the four spacecraft, traveling at 600 kilometers from each other, approached the bow shock.Instead of reading a similar signature form all four ships, as expected, they showed large fluctuations in the magnetic and electric field surrounding each spacecraft, along with marked variations of the protons in the solar wind that were reflected by the shock back to the Sun.

"The features derived from three different scientific experiments on the Cluster satellites provide the first convincing evidence in favor of the shock reformation model," says Vasili Lobzin of the Centre National de la Recherche Scientifique, Orléans, France, who headed this study.As bow shocks around faraway celestial bodies are linked to some of the most energetic events in the Universe, the reports of their reforming has significant implications for future investigations.

How Do Extreme Temperatures And Pressure Inside A Planet Affect It And Its Life?

2008-01-02T02:28:00.000-08:00

Recently, a team of researchers have been able to recreate the extreme conditions of pressure and temperature found inside our planet to understand how it is forming and evolving. The exotic high pressure inner world may be a window to understand a variety of problems in planetary science.In a workshop entitled Synergy of 21st Century High-Pressure Science and Technology sponsored by the Carnegie/DOE Alliance Center and organized by Carnegie’s Geophysical Laboratory scientists Ho-kwang (Dave) Mao and Russell J. Hemley, the two discussed many phenomena encountered deep within the Earth.

"There is a rich history surrounding certain fundamental questions, such as how materials deep within the Earth rise as plumes, and what happens happened to plates as they push against each other and dive below others to great depths," explained Hemley. "But it’s just recently that we’ve been able both to produce the ultrahigh pressures found in the deep Earth and to harness tools that can measure the changes in matter in this extreme environment."In such extreme conditions, the materials and chemicals found under a planet's crust suffer profound alterations. The paper presents many of the internal mechanisms of our planet, which could also apply to extrasolar planets with similar compositions.Deep earhquakes, micro- to nanometer-size minerals and many more could be applied to study the even higher pressures and temperature of the interiors of giant planets, such as Jupiter and even Earth-like planets from other regions of space and how lifeforms could be influenced by the underground conditions.For instance, scientists have recently presented surprising findings about an elusive zone nearly 1,800 miles below the surface near the planet’s core, called the D'' layer, along with seismological and mineral data.Even though the paper focuses on the Earth and planetary sciences, it's also contributing to our understanding of the planets outside our solar system and revealing how life may have originated.

Secrets Of The Face

2008-01-01T00:55:00.001-08:00

Is it really possible to judge someone's character from their faces? The Chinese seem to think so. For over 2,000 years they have been practising SIANG MIEN , which is the art of judging character and predicting fortune from an analysis of the face. It developed in the ancient imperial court of China and consisted of jealously guarded secrets that were passed from masters to a few chosen apprentices. The secrets of face analysis were hidden away in special books which only a few could look at.
These secrets cannot have been that well-guarded and must have got out because practically all Chinese practise some form of face analysis. Mothers tell their daughters that men with flat noses and small ear lobes will make shy and rather dull husbands.
So how does this analysis work? Well, to start with, people's faces can be classified according to one of ten basic shapes, each of which has its own special name. A triangular face, for example, is called a FIRE FACE. One which is square is known as a WALL FACE, while one which is diamond shaped is a JADE FACE. There are even BUCKET FACES!
Once the basic shape has been decided, then parts of the face such as eyes, nose, chin and mouth can be analysed in their turn. People who haven't got conventional or beautiful faces should not worry, as ugly people tend to be lucky.
Anyway, let us see how SIANG MIEN works by using Princess Diana as a practical example. To begin with, we can say that she has got a jade-face which means that she must be strong-willed. This shape also belongs to people who are said to have had difficult childhoods. As you may know, the Princess's parents were divorced when she was a child and this time must have been a period of great unhappiness.
Turning to more specific features, we can see that one eye is a little larger than the other. It is a known fact that people with eyes of different sizes are often brought up by step-parents. They are also believed to be charming as well of being capable of great jealousy. We can see this from this photograph that the top of her ears goes above the line of her eyebrows. People who have high ears such as hers are likely to become famous before the age of 30, while those who combine this with eyes of different sizes will be lucky.

Sleeping Like A Baby

2007-12-30T14:49:00.000-08:00

We do it. Animals do it. Even plants do it. Night after night we close our eyes and are "dead to the world" for hours. Have you ever wondered why we sleep, and what happens to your body and your brain once you have shut your eyes? Thanks to research carried out in sleep laboratories it is now possible to find out.

The sleep cycle has 3 different phases which are repeated through the night.

It is 10 o'clock at night. 3-month-old Rose has just gone to sleep. Doctors have attached wires from her face and head to a special machine in order to record the activity of her brain during the night. Despite the fact that it looks completely still, Rose's body can react to her environment. If you touched her face gently, her hand would push yours away. Rose has entered a phase of her sleep cycle called light sleep.

It is now 10.30. Whereas a few minutes ago she would have responded to gentle touching, Rose now doesn't react to noise or any other minor disturbance. She has now entered a new phase of sleep, deep sleep. Scientists used to think that the purpose of this phase was for the body to recover from physical activity. However, this has been proved wrong.We now know that the main purpose of deep sleep is to give the brain a rest from mental activity. For this reason, the substance which makes us grow is made during these periods of deep sleep.In addition, deep sleep is essential for our good health and happiness. This makes deep sleep all more important.

At 11.30, after another period of light sleep, Rose enters the final phase of the sleep cycle:paradoxical sleep. It is called "paradoxical" because , on one hand, our muscles are inactive but, on the other hand, our brain is even more active than when we are awake. The rapid eye movements of our eyes show this intense mental activity. During this phase our brains memorise what we have learnt when we were awake. So when you're revising for an exam, remember to get plenty of sleep. Otherwise you'll forget what you learnt! Babies have a lot to learn and memorise. Consequently, from the age of 12 we spend only 20% of our sleep time in this phase whereas they spend 60% of their nights in paradoxical sleep.

Rose's face is showing lots of different emotions. The amazing thing is that at her age she still can't show these emotions when she's awake. What is happening? Rose is dreaming. Some people believe that the real meaning of a dream is locked away in the back of the dreamer's mind.

If you are unlucky enough to have insomnia one night, watch other members of your family sleeping. Perhaps you can guess what phase they are in and from the expressions on their faces you may even guess what they are dreaming!

Phantom Travellers

2007-12-29T00:58:00.000-08:00

Despite the fact that explorers and great travellers tend to be hard-headed and practical, many of them sensed a ghostly companion on their travels. Marco Polo was one of the first to describe this. During the 13th century, he crossed the Lop Nor desert on the way to China, and told the following spooky tale:

"When a man is riding by night through this desert and something happens to make him stop and lose touch with his companions...then he hears spirits talking in such a way that they seem to be his companions. Sometimes, indeed, they call him by name..."

Other explorers have also written about this feeling. Despite the failure of Ernest Shackleton's Antarctic journey- his ship broke up in the ice -the written account of it, South, has become famous. T.S. Elliot was inspired by it when he wrote The Waste Land.

Shackleton wrote:

"I know that during that long march of 36 hours over the unnamed mountains and glaciers it often seemed to me that we were four, not three."

Explorer Steve Martin and his two team mates even made "the 4th man" an official member of the party when they were crossing Greenland! Even though there were only three men on the expedition, they felt a fourth presence who always walked to the left of the party. They called him Fletch and he even got into the recent books. "It was a bit of a joke, but having a fourth member along meant you could always blame something on Fletch!" Martin says.

Despite feeling his presence constantly, Martin never actually saw Fletch.

It is unlikely that so many serious explorers were lying. Were their minds affected by the difficult conditions experienced during their travels, or could there be another , more mysterious explanation?

Exploring The World

2007-12-26T01:38:00.000-08:00

Science has learnt a great deal from polar expeditions. For instace, we now know a lot more about the effects polar conditions have on a person's mind and body.
In the early days, explorers often went mad. One cause of this madness was later discovered:when people aren't used to living in extreme cold, their bodies use up a lot of energy to keep warm and this gets rid of all vitamins in the body. The brain, deprived of vitamins, can't work normally, at least until the body gets used to the cold. After a certain period, the body adaps itself to its new environment and makes the most of whatever vitamins are available.
The time spent in total darkness also has a negative effect on people's minds. Winter in polar regions is characterised by permanent night and lasts several months. Human beings are not used to spending long periods of time in the dark.In northern latitudes people get depressed during the dark winter months. Now we know that this depression -known as SAD (Seasonal Affective Disorder)-can be reduced by the use of sun lamps.
Low temperatures can cause any part of the body to freeze. This painful condition is called frostbite. Although the body does get used to functioning in low temperatures, the danger of frostbite is always there if temperatures fall below freezing point. Nowadays, polar explorers carry medication which they can take to allow the blood to flow and slowly defrost the affected parts.
Another common disorder is altitude sickness. The ice is sometimes more than tree kilometres thick, which makes Antarctica one of the highest regions in the world. At that altitude there is little oxygen, so headaches, vomiting and dehydration-the symptoms of altitude sickness-are common. After about a year at high altitude, the body gets used to the lack of oxygen in the air. It compensates by storing more oxygen in the blood.

History Of Iridology

2007-12-24T02:28:00.000-08:00

Where does Iridology come from?
The earliest documentation dates back to the early 1800’s. A Hungarian physician by the name of Ignatz von Pecaely had an experience as a child where he saw strange markings in the iris of an injured owl. Later on as a physician he recalled this experience and started observing his patients' eyes, carefully documenting all his observations.
In the mid 1800’s, a Swedish doctor by the name of Nils Liljequest also documented his observations. At about the same time a German practitioner – Pastor Emanuel Felke developed his skills in iris diagnosis. Emanuel Felke’s contribution to iridology was extensive. His work was documented and furthered by his students since 1857 right up to today. Due to his work, the Felke Institute was established by Dr Willy Hauser in the late 1900’s.
In America Dr Henry Lane and Dr Henry Lindlahr documented and published their work in the early 1900’s. Out of their work the Lindlahr College was born.
The most prominent influence on international iridology came from Bernard Jensen – who travelled and taught iridology all over the world.
The Australian and South African iridology developed from the European and American influences.

Iridology works because the iris records everything that has happened to the body since the age of six. It also carries genetic information which indicates future problems. The colour of the iris also provides the practitioner with vital information.

It's All In The Eye

2007-12-22T23:20:00.000-08:00

Iridology can be defined as the science of studying and analyzing the signs in the iris.
Iridology is a non-invasive diagnostic technique that provides a trained practitioner with important information of a patient’s overall state of health and strengths and weaknesses. The iris can be called the fingerprint of the body, as it reveals each individual’s genetic make-up.
The ability to view not only the quality of the connective tissue of the iris, but also the functioning of the nervous systems, makes iridology an extremely powerful tool. The nervous system connects the iris directly to the brain. This iris displays, like a television screen, every single stimulus from the body that the brain receives. It is for this reason that any change in the body’s functions, or any disturbance in homeostasis can be seen and interpreted. The tissue changes that take place in the body makes iridology especially valuable in the treatment of chronic disease.
The signs in the iris reflect the genetic inherited pattern in constitutions, together with structural, colour and neurological changes that occur within the iris over a period of time.
These signs may indicate abnormal tissue conditions.

How does it work?
Landmark signs and the density of fibres in relation to the over-all constitution are studied. Every landmark sign has its own unique history and the trained practitioner reads and considers the many possible inherent, reflex, chemical, nerve and mental interactions of each system in the individual. A trained practitioner uses iridology to gain an insight into the whole picture before determining the cause behind the problem.
Iridology cannot determine disease; instead it recognizes the individual constitution, inherent strengths and weaknesses, toxins and their location, poor waste clearance, inflammation, biochemical deficiencies and the general health of the individual. The practitioner can detect signs of biochemical and physiological needs and changes in the body long before the appearance of symptoms, thus enabling him/her to prevent disease before it can manifest.

A Brief History Of Life On Earth

2007-12-22T00:10:00.000-08:00

The planet Earth was probably born about 4,500 million years ago, but for hundreds of millions of years after that there was no life here. There were strong winds and rain fell very heavily. There were no plants to stop the sun's rays hitting the planet with their full force.

Rocks from about 2,700 million years ago show some signs of the existence of life but at that time no organisms existed. When a chemical compound of a certain size and complexity was formed, "life" was part of it. The first of these living chemicals were probably like the viruses we know today. From this "virus" stage the next development was to an organism: a number of viruses together. Today we call this type of organism "bacteria". There are clear indications that bacteria lived on Earth long before there were other higher types of life.

"Flagellates" were the next stage in the evolution of life. Some could make their own food, like plants. Other could break down organic matter and others could swallow their food whole, like animals. They form a stage of life before plants and animals were clearly separated from each other.

About 1,500 million years ago various seaweeds , creatures like jellyfish and worms appeared. Soon most of the main groups of animals without backbones were in existence.

It was as recently as 350 million years ago that the first life appeared on land. However, it was only in the last million years that primitive man appeared. From the Stone Age to the age of the Atom, human evolution has been rapid.

In The Wild-Part III

2007-12-20T23:44:00.000-08:00

During the war, some females left the losing side to join the aggressors. Although they were accepted ,not one of their babies was allowed to live.This is a common pattern in other animals, and the adoption of infants from an alien group is unknown in other species apart from man. Nevertheless, older chimps may adopt younger brothers or sisters if the mother dies.
This may help us understand why step fatherhood can be unsuccessful for humans and how difficult it may be to create artificial families. Child-beating is at its most common where stepparents are concerned. It may be just too difficult for most people to truly accept children that are not their own.
Goodall is currently studying how the early experiences of baby chimps affect them in later life-particularly how a badly mothered chimp will become a bad mother herself. Such research may give us clues about human behaviour and motivation. She writes, "Because chimps are less complex, it is easier to study these effects. The scars of childhood are less apparent where human beings learn how to hide their feelings".

In The Wild -Part II

2007-12-19T23:57:00.000-08:00

However, not everything about chimps is so cosy and comfortable. Starting in the early seventies, Jane Goodall was horrified to observe a prolonged war waged by one group of chimps on another "tribe" which had broken away some years earlier. This observation altered her perception of chimps, making them seem, in her eyes, even closer to humans. It had always been thought that humans were the cruelest of animals, and that what made us unique war our habit of making war on one another. The chimps' war showed that this was not the case.

It appears that there was no reason for the conflict other than a perhaps natural hostility to aliens. Even though the younger males were the most aggressive of the group , they were sometimes joined by a single, aggressive female.Chimps in the enemy group were hunted individually and cruelly killed. The excitement and enjoyment Jane Goodall witnessed were very similar to that shown by human beings taking part in war or criminal activity.

Despite the fact that a lion may kill a zebra for food or a bull may fight to assert its dominance over the herd, this "law of jungle" must be distinguished from the behaviour of the chimps. It has been claimed that war was a key factor in developing human social organisation and the selection of the strongest and most intelligent. Jane Goodall believes that she may have witnessed this in its earliest stage of development.

In The Wild - Part I

2007-12-19T00:37:00.000-08:00

Do you think we can learn anything about ourselves by studying animals and their behaviour? Note what human beings and chimpanzees have in common.

For 25 years now, Jane Goodall has been studying chimpanzees at Gombe in Tanzania. This has already become the longest project on animals living in the wild. However, she intends to carry on her research for the rest of her life, as chimps can live for anything up to 50 years. In this way, she hopes to observe the progress of an entire generation of chimps from birth to death.
The most surprising discovery of the early years of her research was that chimps used tools. For example, they poked small branches into holes in trees in order to extract insects to eat. Before this discovery, people had thought that chimps weren't intelligent enough to use tools. Another distinction between chimpanzees and human beings had been eliminated.
There are, of course, many easily observed similarities. Chimps kiss and cuddle like humans. Furthermore, they are self-aware and can recognise themselves in mirrors, which other animals are unable to do. Strong family relationships are seen to exist and even adolescent chimps run back to mother when they find themselves in trouble! What's more, chimps seem to have some kind of structured language in which they can express a number of abstract concepts.

Where on Earth -Part II

2007-12-18T00:14:00.000-08:00

In Darwin's time,there were very few natural predators and a balance of the different species existed. Wild birds showed so little fear that the first men could walk up to to them and touch them without flying off. The biggest danger once upon a time was the occasional fire which helped to keep the tortoise population down.
However, the early visitors brought some unwelcome guests : they introduced rats,cats,pigs and dogs, which grew in number and preyed upon the iguanas and ate the tortoises' eggs. These creatures, part of an evolutionary process of millions of years, were in danger of being lost in hundreds.
Fortunately, radical steps were taken to hunt and destroy as many of these invaders as possible, although the wild cats and rats have proved difficult to find. In recent years, a new threat has appeared in the form of tourism. Despite the government of Ecuador's best efforts , the tide of tourists , which appears irresistible, may again upset the fine balance of nature of the unpopulated islands.

Where on Earth?

2007-12-17T09:34:00.000-08:00

If you could visit anywhere in the world, where would it be? What is the most remote or isolated place you have ever been to?

One of the most remote places in Earth surely has to be the Galapagos Islands, which impose in the Pacific Ocean 1100 kilometres to the west of Ecuador. These inhospitable islands made largely from volcanic rock were allowed to go their own way for millions of years without human interference.

Most notably, the islands are home to the giant tortoise and iguanas. There are also turtles weighing up to 230 kilos and even a cormorant which cannot fly!

The islands were not disturbed until a few hundred years ago when pirates came across them and buried their treasure there.Unpopular crew members were often "mislaid" there too! Later, in 1835, Charles Darwin visited the islands in order to study the wildlife and used his observations as the basis for his theories of natural selection and evolution. He noticed, for example, that many of the islands had their own species of tortoise which had evolved according to each environment in isolation over millions of years.

To Be Continued........

WELCOME

2007-12-16T18:28:00.000-08:00

"Mysteries Of Earth Revealed" will take you in the fascinating world of discovery with the help of studies and explanations of dilemmas of our times. Suddenly, you will see the world in a whole different light!
Once you get on "Mysteries Of Earth Revealed", you will enter the amazing universe of science. Not just simple facts,but fully detailed explanations, everything presented in an attractive way.
A great source of discovering the mysteries of our planet without having to check endless bookstores out.