A comet or some other extraterrestrial object appears to have slammed into northern Canada 12,900 years ago and triggered an abrupt and catastrophic climate change that wiped out the mammoths and many other prehistoric creatures, according to a team of U.S. scientists.
Evidence of the ecological disaster exists in a thin layer of sediment that has been found from Alberta to New Mexico, say the researchers, whose work adds a dramatic and provocative twist to the decades-old debate about the demise of the mammoths, mastodons and sloths that once roamed North America.
Science & Technology
A blink lasts about a 10th of a second, and most people blink about 15 times a minute, or every 4 seconds.
Obviously there is some cleaning and lubrication of the eye that gets handled by blinking, and you certainly know that if you get something in your eye you'll start blinking fiercely. You can also experiment with stopping yourself from blinking and will find after a while that it's a bit uncomfortable. A blink can also be a protective mechanism against bright lights, as any photography buff is only too well aware! Similarly, you may well blink in the presence of irritants like freshly cut onions or tear gas.
Blink rates vary quite a bit depending on emotional and mental states. Stress and anxiety tend to increase a person's blink rate, and this can sometimes give away a lie. Intense concentration tends to reduce the blink rate, and if you're in a situation that implies some danger, your blinking rate can go way down -- presumably to help you look around quickly without missing things.
Obviously there is some cleaning and lubrication of the eye that gets handled by blinking, and you certainly know that if you get something in your eye you'll start blinking fiercely. You can also experiment with stopping yourself from blinking and will find after a while that it's a bit uncomfortable. A blink can also be a protective mechanism against bright lights, as any photography buff is only too well aware! Similarly, you may well blink in the presence of irritants like freshly cut onions or tear gas.
Blink rates vary quite a bit depending on emotional and mental states. Stress and anxiety tend to increase a person's blink rate, and this can sometimes give away a lie. Intense concentration tends to reduce the blink rate, and if you're in a situation that implies some danger, your blinking rate can go way down -- presumably to help you look around quickly without missing things.
Researchers have installed a seismometer atop an active volcano called Kick 'em Jenny under the Caribbean Sea to warn of eruptions or earthquake activity, scientists said Saturday.
The device allows scientists to collect real-time rumbling from tremors or as bubbling magma and gases are released from the volcano, about 820 feet beneath the sea's surface off Grenada's northwest coast.
"The system essentially acts as a kind of doctor's stethoscope so we can directly listen to the pulse of the volcano," said Richard Robertson, director of the Seismic Research Unit at the University of the West Indies in Trinidad.
He said the seismometer is connected to a flexible hose that runs to a buoy, where a high-frequency radio transmitter sends readings to an observatory in a northern Grenadian village - all within milliseconds.
A team of scientists led by the Woods Hole Oceanographic Institution in Massachusetts attached the monitoring system to the volcano by a remote-controlled underwater craft on May 6.
The device allows scientists to collect real-time rumbling from tremors or as bubbling magma and gases are released from the volcano, about 820 feet beneath the sea's surface off Grenada's northwest coast.
"The system essentially acts as a kind of doctor's stethoscope so we can directly listen to the pulse of the volcano," said Richard Robertson, director of the Seismic Research Unit at the University of the West Indies in Trinidad.
He said the seismometer is connected to a flexible hose that runs to a buoy, where a high-frequency radio transmitter sends readings to an observatory in a northern Grenadian village - all within milliseconds.
A team of scientists led by the Woods Hole Oceanographic Institution in Massachusetts attached the monitoring system to the volcano by a remote-controlled underwater craft on May 6.
Astronomers have used a unique process to determine that a star in our galaxy is nearly as old as the universe itself.
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| ©ESO via livescience.com |
| The Big Bang occurred 13.7 billion years ago, making the Milky Way star HE 1523 the oldest-known star at 13.2 billion years old. The star's age was gleaned from what's left of its radioactive elements compared to stable "anchor" elements, like europium, osmium, and iridium. |
Does your house address start with a 1? According to a strange mathematical law, about 1/3 of house numbers have 1 as their first digit. The same holds true for many other areas that have almost nothing in common: the Dow Jones index history, size of files stored on a PC, the length of the world's rivers, the numbers in newspapers' front page headlines, and many more.
The law is called Benford's law after its (second) founder, Frank Benford, who discovered it in 1935 as a physicist at General Electric. The law tells how often each number (from 1 to 9) appears as the first significant digit in a very diverse range of data sets.
The law is called Benford's law after its (second) founder, Frank Benford, who discovered it in 1935 as a physicist at General Electric. The law tells how often each number (from 1 to 9) appears as the first significant digit in a very diverse range of data sets.
A group of Russian scientists from Tomsk, Yekaterinburg, Nizhny Novgorod and Moscow have developed a series of unique compact generators capable of producing high-energy pulses of hundreds and even thousands of megawatts.
This compares with the capacity of a major Soviet hydropower station on the Dnieper or an energy unit at a modern nuclear power plant. The new generators are sources of electromagnetic radiation rather than electricity. Their main feature is a capacity to produce enormous power in a matter of nanoseconds. The impulses can be generated with a very high frequency.
Vice President of the Russian Academy of Sciences (RAS) Gennady Mesyats recalled that the first high-current electron accelerators were developed in the U.S.S.R. in the 1960s. Ten years later, Soviet scientists learnt to generate powerful microwave nanosecond pulses. The current generators have no counterparts in the world. In effect, Russian scientists have made a breakthrough in what is called relativist high-precision electronics.
This compares with the capacity of a major Soviet hydropower station on the Dnieper or an energy unit at a modern nuclear power plant. The new generators are sources of electromagnetic radiation rather than electricity. Their main feature is a capacity to produce enormous power in a matter of nanoseconds. The impulses can be generated with a very high frequency.
Vice President of the Russian Academy of Sciences (RAS) Gennady Mesyats recalled that the first high-current electron accelerators were developed in the U.S.S.R. in the 1960s. Ten years later, Soviet scientists learnt to generate powerful microwave nanosecond pulses. The current generators have no counterparts in the world. In effect, Russian scientists have made a breakthrough in what is called relativist high-precision electronics.
Astronomers believe they may have found a significant portion of the universe's "missing" matter.
The mysterious dark matter may be giving invisible heft to small galaxies formed during galactic collisions, a new study says.
Dark matter is an invisible form of matter that does not give off or reflect light yet accounts for the vast majority of mass in the universe.
Scientists measured the mass of three so-called recycled dwarf galaxies near a massive galaxy that was recently in a collision.
The dwarfs appear to be more than twice as heavy as their visible stars and gas, indicating that they hold a type of dark matter.
The mysterious dark matter may be giving invisible heft to small galaxies formed during galactic collisions, a new study says.
Dark matter is an invisible form of matter that does not give off or reflect light yet accounts for the vast majority of mass in the universe.
Scientists measured the mass of three so-called recycled dwarf galaxies near a massive galaxy that was recently in a collision.
The dwarfs appear to be more than twice as heavy as their visible stars and gas, indicating that they hold a type of dark matter.
Tiny igloos can generate "micro-tornadoes" in the lab, which could allow scientists to better understand the destructive secrets of real-life twisters-and maybe help predict them.
The translucent igloos, made of tiny water droplets and plastic balls, are only millimeters across. As these crystalline domes evaporate on Petri dishes-sometimes taking as long as nearly eight days to finish dissipating-they create micro-tornadoes under their roofs just roughly half the width of a human hair.
Real-life tornadoes are essentially natural engines, where warm, humid air from the ground rises upward into the colder atmosphere, converting heat into mechanical violence in the process. The result-the world's most powerful winds.
The translucent igloos, made of tiny water droplets and plastic balls, are only millimeters across. As these crystalline domes evaporate on Petri dishes-sometimes taking as long as nearly eight days to finish dissipating-they create micro-tornadoes under their roofs just roughly half the width of a human hair.
Real-life tornadoes are essentially natural engines, where warm, humid air from the ground rises upward into the colder atmosphere, converting heat into mechanical violence in the process. The result-the world's most powerful winds.
After Japanese insurance kingpin Yasuo Goto won a high-stakes bidding war by offering $39.9 million for a painting at a 1987 auction, an unforeseen controversy erupted: Was the painting, Vincent van Gogh's Still Life: Vase With Fifteen Sunflowers, truly the work of the Dutch master, or a clever fake?
Some art dealers and historians thought the character of the brushstrokes differed from other Van Goghs; others disagreed. The stalemate was never resolved. But after 20 years, help is finally arriving from an unlikely quarter. Computer scientist Richard Johnson of Cornell University in Ithaca, N.Y., is embarking on an international project to define Van Gogh's unique style in mathematical terms, with the intent of shining a focused beam of objectivity on the traditionally muddled question of attribution.
On May 14, teams of engineers that Mr. Johnson recruited will meet with art students and curators at the Van Gogh Museum in Amsterdam to announce what they think sets real Van Gogh paintings apart from forgeries. By analyzing a database of 101 paintings by the artist and his known imitators, the scientists have arrived at what they say are key elements of Van Gogh's "visual signature," which can be distilled into numbers. This, they say, will give art experts an important new tool to assess works like Vase With Fifteen Sunflowers. They can compare how closely a disputed painting's visual signature matches the baseline "signature" derived from the database.
Some art dealers and historians thought the character of the brushstrokes differed from other Van Goghs; others disagreed. The stalemate was never resolved. But after 20 years, help is finally arriving from an unlikely quarter. Computer scientist Richard Johnson of Cornell University in Ithaca, N.Y., is embarking on an international project to define Van Gogh's unique style in mathematical terms, with the intent of shining a focused beam of objectivity on the traditionally muddled question of attribution.
On May 14, teams of engineers that Mr. Johnson recruited will meet with art students and curators at the Van Gogh Museum in Amsterdam to announce what they think sets real Van Gogh paintings apart from forgeries. By analyzing a database of 101 paintings by the artist and his known imitators, the scientists have arrived at what they say are key elements of Van Gogh's "visual signature," which can be distilled into numbers. This, they say, will give art experts an important new tool to assess works like Vase With Fifteen Sunflowers. They can compare how closely a disputed painting's visual signature matches the baseline "signature" derived from the database.
Scientists have discovered how ocean circulation is working in the current that flows around Antarctica by tracing the path of helium from underwater volcanoes.
The team, which included researchers from the University of East Anglia, has discovered a 'short-circuit' in the circulation of the world's oceans that could aid predictions about future climate change.
This process in the Southern Ocean allows cold waters that sink to the abyss to return to the surface more rapidly than previously thought.
This affects the Southern Ocean circulation, which links all the other oceans, and is also relevant to uptake and release of carbon dioxide by the sea - transport between the deep and surface waters in the Southern Ocean is particularly important for this process.
The team, which included researchers from the University of East Anglia, has discovered a 'short-circuit' in the circulation of the world's oceans that could aid predictions about future climate change.
This process in the Southern Ocean allows cold waters that sink to the abyss to return to the surface more rapidly than previously thought.
This affects the Southern Ocean circulation, which links all the other oceans, and is also relevant to uptake and release of carbon dioxide by the sea - transport between the deep and surface waters in the Southern Ocean is particularly important for this process.
Comment: More evidence that backs up the story that we relate in the article Forget About Global Warming: We're One Step From Extinction!. For an in-depth analysis of this event, check out the book The Cycle of Cosmic Catastrophes: Flood, Fire, and Famine in the History of Civilization. See also Laura Knight-Jadczyk's The Secret History of the World, which covers this subject thoroughly.