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Sir Isaac Newton was possibly the greatest scientist who ever lived. But even great men can make mistakes – it’s just that their errors are more interesting than other people’s. Newton’s law of motion (force equals mass times acceleration) is taught in every high school. Newton’s law of gravitation (the inverse-square law) is precise enough to be used by NASA for space mission design and was used by Newton himself to determine the motion of the planets.
Read full article Continue reading page | 1 | 2 The Large Hadron Collider has turned up differences in how particles of matter and antimatter decay that the reigning standard model of physics may not be able to explain WE ARE here thanks to a curious imbalance in the universe. To the best of our knowledge, the universe began with equal, or nearly equal, amounts of matter and antimatter. Because these particles annihilate on contact, they should have destroyed each other long ago in a blaze of radiation, leaving little if anything behind to form stars, planets and people.
Why does our universe look the way it does? In particular, why do we only experience three spatial dimensions in our universe, when superstring theory, for instance, claims that there are ten dimensions — nine spatial dimensions and a tenth dimension of time? Japanese scientists think they may have an explanation for how a three-dimensional universe emerged from the original nine dimensions of space.
This image of a full-energy collision between gold ions shows the paths taken by thousands of subatomic particles produced during the impact. For a brief instant, it appears, scientists at Brookhaven National Laboratory on Long Island recently discovered a law of nature had been broken. Action still resulted in an equal and opposite reaction, gravity kept the Earth circling the Sun, and conservation of energy remained intact. But for the tiniest fraction of a second at the Relativistic Heavy Ion Collider (RHIC), physicists created a symmetry-breaking bubble of space where parity no longer existed. Parity was long thought to be a fundamental law of nature. It essentially states that the universe is neither right- nor left-handed — that the laws of physics remain unchanged when expressed in inverted coordinates.
By William J. Cromie Gazette Staff "Two years ago we slowed it down to 38 miles an hour; now we've been able to park it then bring it back up to full speed." Lene Hau isn't talking about a used motorbike, but about light – that ethereal, life-sustaining stuff that normally travels 93 million miles from the sun in about eight minutes.
Physicists have created a new kind of light by chilling photons into a blob state. Just like solids, liquids and gases, this recently discovered condition represents a state of matter. Called a Bose-Einstein condensate, it was created in 1995 with super-cold atoms of a gas, but scientists had thought it could not be done with photons, which are basic units of light .
Last September I had an article in Scientific American about what it would mean for time to end—how the world might cease to unfold in a unidirectional sequence of cause and effect. Some processes, for example, could cause time to morph into just another dimension of space . Last week experimenters announced that they have simulated such a temporal calamity in the laboratory. Unable to keep up with the gush of physics papers on the preprint server anymore, I came across this one on the arXiv blog , which I highly recommend to all physics aficionados. What Igor Smolyaninov of the University of Maryland and his colleagues have done is indirect—an analogy to an analogy. They did not bring time as we know it to a crashing halt.
More Science :: News :: December 1, 2011 :: :: Email :: Print Usually a finicky phenomenon limited to tiny, ultracold objects, entanglement has now been achieved for macroscopic diamonds at room temperature By John Matson
Space :: Features :: February 10, 2012 :: :: Email :: Print An excerpt from physicist Lawrence M. Krauss's new book explains why we are not the center of the universe
More Science :: Skeptic :: April 27, 2012 :: :: Email :: Print See Inside Science closes in on why there is something instead of nothing By Michael Shermer Image: Illustration by Neil Webb Why is there something rather than nothing?
It is, perhaps, the mystery of last resort. Scientists may be at least theoretically able to trace every last galaxy back to a bump in the Big Bang, to complete the entire quantum roll call of particles and forces. But the question of why there was a Big Bang or any quantum particles at all was presumed to lie safely out of scientific bounds, in the realms of philosophy or religion. Now even that assumption is no longer safe, as exemplified by a new book by the cosmologist Lawrence M. Krauss . In it he joins a chorus of physicists and cosmologists who have been pushing into sacred ground, proclaiming more and more loudly in the last few years that science can explain how something — namely our star-spangled cosmos — could be born from, if not nothing, something very close to it.
Mysterious, unseen structures on the outskirts of creation most likely aren't tugging on our universe, according to a new study. The paper reexamines "dark flow"— an unusual, one-way motion of matter —using measurements of supernovae and the existing laws of physics. In 2008, a team of scientists took measurements of hundreds of galaxy clusters and calculated that everything in the visible universe—and likely beyond—is flowing at 2 million miles (3.2 million kilometers) an hour in the same direction. The data couldn't be explained by the distribution of matter in the known universe, so the scientists suggested that chunks of matter had been pushed out shortly after the big bang , and their gravity is now pulling on everything around us. In 2010 the same team released a second study with data on twice as many galaxy clusters as their 2008 work.
Image: Chad Hagen Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way... Read More » Editor's note: In the August issue of Scientific American, cosmologist George Ellis describes why he's skeptical about the concept of parallel universes. Here, multiverse proponents Alexander Vilenkin and Max Tegmark offer counterpoints, explaining why the multiverse would account for so many features of our universe—and how it might be tested. Welcome to the Multiverse By Alexander Vilenkin
Stand up. Walk 10 feet straight ahead. Turn left by 90 degrees.