×
Earth

How Earth's Biosignature Will Change As the Planet Dies 95

Posted by Soulskill from the we'll-have-to-start-forging-another-planet's-biosignature dept.
KentuckyFC writes "As the Sun expands into a red giant, life on Earth will die away. Now astrobiologists have worked out how this will look to distant observers watching the biosignature in our atmosphere. They say the first major effect of warming, about 1 billion years from now, will be a dramatic drop in atmospheric carbon dioxide as the oceans absorb more of it. That's bad news for trees and plants, which need carbon dioxide for photosynthesis, so they begin to die off. Since plants produce oxygen, atmospheric levels of oxygen will also drop, killing off the animals. Roughly 2 billion years from now, the only living things on Earth will be microbes. However, methane levels will have risen dramatically, caused by decaying plant matter. And decaying animals will release a gas called methanethiol, which breaks down into ethane, which ought to be visible too. Finally, they calculate that about 3 billion years from now, the oceans will boil and Earth will be a barren planet with little if any biosignature at all. But all this is not just a subject of morbid fascination. With the next generation of space telescopes, astronomers should see similar biosignatures on Earth-like planets around other stars that are also beyond their sell-by dates. So we'll be able to watch them die off first."
Science

Cornell Team Says It's Unified the Structure of Scientific Theories 115

Posted by Soulskill from the i-think-therefore-something-something dept.
An anonymous reader writes "Cornell physicists say they've codified why science works, or more specifically, why scientific theories work – a meta-theory. Publishing online in the journal Science (abstract), the team has developed a unified computational framework they say exposes the hidden hierarchy of scientific theories by quantifying the degree to which predictions – like how a particular cellular mechanism might work under certain conditions, or how sound travels through space – depend on the detailed variables of a model."
Supercomputing

Scientists Using Supercomputers To Puzzle Out Dinosaur Movement 39

Posted by Soulskill from the turns-out-they-sucked-at-ballet dept.
Nerval's Lobster writes "Scientists at the University of Manchester in England figured out how the largest animal ever to walk on Earth, the 80-ton Argentinosaurus, actually walked on earth. Researchers led by Bill Sellers, Rudolfo Coria and Lee Margetts at the N8 High Performance Computing facility in northern England used a 320 gigaflop/second SGI High Performance Computing Cluster supercomputer called Polaris to model the skeleton and movements of Argentinosaurus. The animal was able to reach a top speed of about 5 mph, with 'a slow, steady gait,' according to the team (PDF). Extrapolating from a few feet of bone, paleontologists were able to estimate the beast weighed between 80 and 100 tons and grew up to 115 feet in length. Polaris not only allowed the team to model the missing parts of the dinosaur and make them move, it did so quickly enough to beat the deadline for PLOS ONE Special Collection on Sauropods, a special edition of the site focusing on new research on sauropods that 'is likely to be the "de facto" international reference for Sauropods for decades to come,' according to a statement from the N8 HPC center. The really exciting thing, according to Coria, was how well Polaris was able to fill in the gaps left by the fossil records. 'It is frustrating there was so little of the original dinosaur fossilized, making any reconstruction difficult,' he said, despite previous research that established some rules of weight distribution, movement and the limits of dinosaurs' biological strength."

Slashdot Top Deals