Science & Technology
New government laboratory test results are fueling a controversial contention that a giant natural nuclear reactor at the center of the Earth powers the planet's life-protecting magnetic field -- but it might be running out of gas, scientists told United Press International.
What are the odds that poker can be explained by statistical physics, much the same as a variety of other complex systems? They're pretty good, according to physicist Clément Sire of Université of Toulouse and CNRS in France, who demonstrates in a recent paper that many of the statistical properties of poker tournaments are universal. Sire's model makes connections between poker and evolution, extreme value statistics and the physical model of persistence.
"In this Letter, we study a very human and futile activity: poker tournaments," Sire writes in his paper, to be published in an APS Physical Review journal. His model quantifies the evolution of Texas hold 'em tournaments, based on aspects such as the distribution of chips, the number of surviving players over time, etc. Overall, his results closely mirror those observed in real-life online tournaments.
"In this Letter, we study a very human and futile activity: poker tournaments," Sire writes in his paper, to be published in an APS Physical Review journal. His model quantifies the evolution of Texas hold 'em tournaments, based on aspects such as the distribution of chips, the number of surviving players over time, etc. Overall, his results closely mirror those observed in real-life online tournaments.
Geophysicists at the University of Rochester announce in today's issue of Nature that the Earth's magnetic field was nearly as strong 3.2 billion years ago as it is today.
The findings, which are contrary to previous studies, suggest that even in its earliest stages the Earth was already well protected from the solar wind, which can strip away a planet's atmosphere and bathe its surface in lethal radiation.
"The intensity of the ancient magnetic field was very similar to today's intensity," says John Tarduno, professor of geophysics in the Department of Earth and Environmental Sciences at the University of Rochester. "These values suggest the field was surprisingly strong and robust. It's interesting because it could mean the Earth already had a solid iron inner core 3.2 billion years ago, which is at the very limit of what theoretical models of the Earth's formation could predict."
The findings, which are contrary to previous studies, suggest that even in its earliest stages the Earth was already well protected from the solar wind, which can strip away a planet's atmosphere and bathe its surface in lethal radiation.
"The intensity of the ancient magnetic field was very similar to today's intensity," says John Tarduno, professor of geophysics in the Department of Earth and Environmental Sciences at the University of Rochester. "These values suggest the field was surprisingly strong and robust. It's interesting because it could mean the Earth already had a solid iron inner core 3.2 billion years ago, which is at the very limit of what theoretical models of the Earth's formation could predict."
It has been a mystery for astronomers how certain dying stars have their colossal quantities of material blown out into the universe and shrink into objects called "white dwarves". This is the basis of a ground-breaking new theory by astrophysicists Anja C. Andersen from the Dark Cosmology Centre at the University of Copenhagen and Susanne Hцfner of the University of Uppsala.
Earth and the other planets in our solar system are built up of elements which have been produced in earlier generations of stars. Deep in the stars' very hot core, the elements are created out of hydrogen, and when the stars explode and die, the elements are shot out into the universe as huge clouds of gas and dust. Gradually, all that dust aggregates, eventually forming new stars and planets.
Pitch-black dust clouds
Stars smaller than our sun and up to eight times as large die by first swelling up to being a red giant, and then shrinking to a white dwarf. There are two types of red giants, one contains lots of carbon and the the other a lot of oxygen. When the carbon-rich stars die, large clouds of carbon particles such as soot and graphite are produced. Soot and graphite are pitch-black, so when the rays from the dying star hit the soot particles they stop the light and are pushed out into space, where they are seen as gigantic dust clouds. This is a 20 year old theory which fits both the observations and the model calculations.
Earth and the other planets in our solar system are built up of elements which have been produced in earlier generations of stars. Deep in the stars' very hot core, the elements are created out of hydrogen, and when the stars explode and die, the elements are shot out into the universe as huge clouds of gas and dust. Gradually, all that dust aggregates, eventually forming new stars and planets.
Pitch-black dust clouds
Stars smaller than our sun and up to eight times as large die by first swelling up to being a red giant, and then shrinking to a white dwarf. There are two types of red giants, one contains lots of carbon and the the other a lot of oxygen. When the carbon-rich stars die, large clouds of carbon particles such as soot and graphite are produced. Soot and graphite are pitch-black, so when the rays from the dying star hit the soot particles they stop the light and are pushed out into space, where they are seen as gigantic dust clouds. This is a 20 year old theory which fits both the observations and the model calculations.
Scientists have been puzzling over the cause of dramatic global warming on Mars, which has made parts of the south polar ice cap disappear in recent years. The answer, it seems, is blowing in the wind: the planet's famous reddish dust.
Using global circulation models similar to those used to analyse Earth's changing climate, a team led by Lori Fenton of NASA's Ames Research Center in California, US, found that Mars seems to have warmed by about 0.65° Celsius in the three decades since the Viking mission first provided detailed mapping of the whole planet.
That warming can be explained entirely by the scouring away of light-coloured dust from darker areas of the surface, causing an increase in the absorption of solar radiation.
Using global circulation models similar to those used to analyse Earth's changing climate, a team led by Lori Fenton of NASA's Ames Research Center in California, US, found that Mars seems to have warmed by about 0.65° Celsius in the three decades since the Viking mission first provided detailed mapping of the whole planet.
That warming can be explained entirely by the scouring away of light-coloured dust from darker areas of the surface, causing an increase in the absorption of solar radiation.
The Global Positioning System (GPS), increasingly vital technology for activities including navigating cars and planes, bank financial transfers and more, may be threatened by powerful radio bursts from the sun, a panel of scientists in the US warned today.
"Our increasingly technologically dependent society is becoming increasingly vulnerable to space weather," David L. Johnson, director of the US National Weather Service, said at a briefing.
GPS receivers have become widely used in recent years, using satellite signals to navigate planes, ships and automobiles, and in the use of mobile phones, mining, surveying and many commercial applications.
"Our increasingly technologically dependent society is becoming increasingly vulnerable to space weather," David L. Johnson, director of the US National Weather Service, said at a briefing.
GPS receivers have become widely used in recent years, using satellite signals to navigate planes, ships and automobiles, and in the use of mobile phones, mining, surveying and many commercial applications.
Educational software, a $2 billion-a-year industry that has become the darling of school systems across the country, has no significant impact on student performance, according to a study by the U.S. Department of Education.
The long-awaited report amounts to a rebuke of educational technology, a business whose growth has been spurred by schools desperate for ways to meet the testing mandates of President Bush's No Child Left Behind law.
The long-awaited report amounts to a rebuke of educational technology, a business whose growth has been spurred by schools desperate for ways to meet the testing mandates of President Bush's No Child Left Behind law.
A rib bone supposedly found at the site where French heroine Joan of Arc was burned at the stake has been found to belong to an egyptian mummy. It is dated between the 7th and 3rd century BC.
The bone, a piece of cloth and a cat femur were said to have been recovered after the 19-year-old was burned in 1431 in the town of Rouen. In 1909 - the year Joan of Arc was beatified - scientists declared it "highly probable" that the relics were hers.
It is specualted that it was faked to boost her standing as a church figure.
The bone, a piece of cloth and a cat femur were said to have been recovered after the 19-year-old was burned in 1431 in the town of Rouen. In 1909 - the year Joan of Arc was beatified - scientists declared it "highly probable" that the relics were hers.
It is specualted that it was faked to boost her standing as a church figure.
OTTAWA - Fearing the effects of forest fires and tree-destroying insect infestations, the federal government has decided against using Canada's forests in the calculations for totalling up the country's greenhouse-gas emissions.
Instead of forests being used as a credit to offset other emissions, the government is now afraid that including forests in the formula could drive up Canada's climate-change burden.
Instead of forests being used as a credit to offset other emissions, the government is now afraid that including forests in the formula could drive up Canada's climate-change burden.
The numbers are damning. Within 15 years 98% of the rainforests of Indonesia and Malaysia will be gone, little more than a footnote in history. With them will disappear some of the world's most important wildlife species, victims of the rapacious destruction of their habitat in what conservationists see as a lost cause.
