A collection of tiny perforated shell beads dates back 75,000 years and appears to be the oldest human ornament ever found.
Archaeologists claim to have discovered the world's oldest beads, dating back around 75,000 years.
Science & Technology
Astrophysicists have found a star-like object with a surface temperature just one tenth that of the Sun.
The cold object is known as a brown dwarf: a "failed" star that never achieved the mass required to begin nuclear fusion reactions in its core.
This one - called J0034-00 - is thought to have a surface temperature of just 600-700 Kelvin (up to 430C/800F).
It is the coldest solitary brown dwarf ever seen, according to the British team that discovered it.
The cold object is known as a brown dwarf: a "failed" star that never achieved the mass required to begin nuclear fusion reactions in its core.
This one - called J0034-00 - is thought to have a surface temperature of just 600-700 Kelvin (up to 430C/800F).
It is the coldest solitary brown dwarf ever seen, according to the British team that discovered it.
At the present international space symposium in Visby, Sweden, one of the topics is the Swedish satellite Odin, which is now on its seventh year of operations. Quite recently, scientists have discovered that Odin's measurements can be used also to study the presence of clouds and aerosols in the stratosphere. Clouds and aerosols may have a cooling effect on our planet, as against the warming effect of carbon dioxide.
Today, scientists do not have sufficient knowledge about the possible cooling effect of clouds. Measurements made in space could determine how much of the sunlight is reflected back into space by clouds. Odin has measured, and is still measuring, the amount of clouds, both visible and invisible to the human eye, and Odin data have indicated significant divergence from existing forecast models. This kind of information could help us improve our knowledge about the processes of global warming. We need more knowledge about our climate, and we need it soon, in order to improve exisiting models in this field.
Today, scientists do not have sufficient knowledge about the possible cooling effect of clouds. Measurements made in space could determine how much of the sunlight is reflected back into space by clouds. Odin has measured, and is still measuring, the amount of clouds, both visible and invisible to the human eye, and Odin data have indicated significant divergence from existing forecast models. This kind of information could help us improve our knowledge about the processes of global warming. We need more knowledge about our climate, and we need it soon, in order to improve exisiting models in this field.
Archaeologists from Oxford have discovered what are thought to be the oldest examples of human decorations in the world.
The international team of archaeologists, led by Oxford University's Institute of Archaeology, have found shell beads believed to be 82,000 years old from a limestone cave in Morocco.
The international team of archaeologists, led by Oxford University's Institute of Archaeology, have found shell beads believed to be 82,000 years old from a limestone cave in Morocco.
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| ©Unk |
| At work in the limestone caves in Morocco |
Analysis of chicken bones found in Chile shows Polynesians reached the continent no later than 1407.
After decades of contention, New Zealand researchers have provided the first direct evidence that Polynesians sailed across thousands of miles of the Pacific Ocean to reach South America long before the arrival of the Spanish around AD 1500.
Their proof? Chicken bones.
After decades of contention, New Zealand researchers have provided the first direct evidence that Polynesians sailed across thousands of miles of the Pacific Ocean to reach South America long before the arrival of the Spanish around AD 1500.
Their proof? Chicken bones.
Fathers of the zodiac tracked down. Astronomer shows when and where his ancient counterparts worked.
Using modern techniques - and some rocks - a US astronomer has traced the origin of a set of ancient clay tablets to a precise date and place. The tablets show constellations thought to be precursors of the present-day zodiac.
The tablets, known collectively as MUL.APIN, contain nearly 200 astronomical observations, including measurements related to several constellations. They are written in cuneiform, a Middle-Eastern script that is one of the oldest known forms of writing, and were made in Babylon around 687 BC.
But most archaeologists believe that the tablets are transcriptions of much earlier observations made by Assyrian astronomers. Just how much older has been disputed - the estimates go back to 2,300 BC.
The tablets, known collectively as MUL.APIN, contain nearly 200 astronomical observations, including measurements related to several constellations. They are written in cuneiform, a Middle-Eastern script that is one of the oldest known forms of writing, and were made in Babylon around 687 BC.
But most archaeologists believe that the tablets are transcriptions of much earlier observations made by Assyrian astronomers. Just how much older has been disputed - the estimates go back to 2,300 BC.
University of Utah physicists developed small devices that turn heat into sound and then into electricity. The technology holds promise for changing waste heat into electricity, harnessing solar energy and cooling computers and radars.
"We are converting waste heat to electricity in an efficient, simple way by using sound," says Orest Symko, a University of Utah physics professor who leads the effort. "It is a new source of renewable energy from waste heat."
Five of Symko's doctoral students recently devised methods to improve the efficiency of acoustic heat-engine devices to turn heat into electricity. They will present their findings on Friday, June 8 during the annual meeting of the Acoustical Society of America at the Hilton Salt Lake City Center hotel.
Symko plans to test the devices within a year to produce electricity from waste heat at a military radar facility and at the university's hot-water-generating plant.
"We are converting waste heat to electricity in an efficient, simple way by using sound," says Orest Symko, a University of Utah physics professor who leads the effort. "It is a new source of renewable energy from waste heat."
Five of Symko's doctoral students recently devised methods to improve the efficiency of acoustic heat-engine devices to turn heat into electricity. They will present their findings on Friday, June 8 during the annual meeting of the Acoustical Society of America at the Hilton Salt Lake City Center hotel.
Symko plans to test the devices within a year to produce electricity from waste heat at a military radar facility and at the university's hot-water-generating plant.
Russian cosmonauts successfully completed a six-hour spacewalk to build up the meteorite defences of the International Space Station (ISS) and repair a navigation antennae, officials said on Thursday.
Forget the 'brightest stellar explosion' of supernova SN 2006gy captured by the Chandra X-Ray Observatory last month. Here's the mother of all spatial explosions in the making - a hypernova called Eta Carinae.
A controversial new idea suggests that a large space rock exploded over North America 13,000 years ago.
The blast may have wiped out one of America's first Stone Age cultures as well as the continent's big mammals such as the mammoth and the mastodon.
The blast, from a comet or asteroid, caused a major bout of climatic cooling which may also have affected human cultures emerging in Europe and Asia.
The blast may have wiped out one of America's first Stone Age cultures as well as the continent's big mammals such as the mammoth and the mastodon.
The blast, from a comet or asteroid, caused a major bout of climatic cooling which may also have affected human cultures emerging in Europe and Asia.
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| ©unk |
| A space rock may have exploded in the air over North America |
Comment: And if it happened once, there's no reason why it couldn't happen again. Particularly if these type of events turn out to be cyclic, as the evidence suggests.