Brian Greene: Back to blow your mind.
Having explained string theory to the masses in his bestseller The Elegant Universe and untangled the fabric of the cosmos in The Fabric of the Cosmos, the superstar physicist returns this month with The Hidden Reality, an ode to multiverse theory.
By now, the 11-dimension string theory models of his earlier books … are looking downright commonsensical. “The Hidden Reality” moves on to increasingly speculative and exotic discussions of a bubble multiverse (“Think of the universe as a gigantic block of Swiss cheese. …”) a holographic one, a brane-world scenario (courtesy of string theory), computer-driven simulations, questions of how probability relates to infinity, and the Many Worlds view of quantum mechanics. “A frequent criticism of the Many Worlds approach is that it’s just too baroque to be true,” Mr. Greene writes. [The New York Times]
Multiverse theory—the idea that our universe and its Big Bang were just one of many—is a favorite theme of science fiction (and “Family Guy”), as it allows us to have parallel selves in parallel universes. Greene explains the real science behind the idea with one of his litany of analogies: a simple deck of cards.
If you shuffle the deck infinitely many times, the card orderings must necessarily repeat. Similarly, in an infinite expanse of space, particle arrangements must repeat too—there just aren’t enough different particle configurations to go around. And if the particles in a given region of space the size of ours are arranged identically to how they are arranged here, then reality in that region will be identical to reality here. Except that maybe we’d be seeing the Jets and the Bears in the Super Bowl. [Wall Street Journal]
You know those black holes the Large Hadron Collider was going to make and kill us all? Well, not only are we still here, but the LHC doesn’t seem to be making black holes at all—their decay signature is markedly absent from the data collected so far.
While that is good for those of us who want to keep living (we jest—the hypothetical micro black holes posed no danger), it’s also helping physicists make up their minds about how many dimensions there are in our universe. The lack of black holes at the LHC nullifies some of the wackier versions of string theory which depend on multiple dimensions.
At the University of Cambridge it’s out with black holes, in with tiny vibrating strings of energy. The prestigious professorship that was most recently held by Stephen Hawking, the physicist whose great contributions to the field include new models of black holes, has been given to the string theory luminary Michael Green.
The Lucasian Professorship was established in 1663 and previous holders have included Isaac Newton [BBC News]; it’s considered one of the most prestigious academic posts in the world. Hawking held the job for 30 years, but stepped down in September following his 67th birthday, in accordance with a university rule.
Stephen Hawking, the world-renowned physicist and author, is reportedly “very ill” and being treated at the hospital. Says University of Cambridge spokesman Greg Hayman: “Professor Hawking is very ill…. He has been suffering from a chest infection for a number of weeks which has meant he has had to cancel a number of appointments.” Hawking was flown back to the U.K. from the U.S. at the weekend, Hayman said. He was taken to hospital at lunch time today [Bloomberg].
Hawking has remained active despite being diagnosed at 21 with ALS, (amyotrophic lateral sclerosis), an incurable degenerative disorder also known as Lou Gehrig’s disease. For some years, Hawking has been almost entirely paralyzed, and he communicates through an electronic voice synthesizer activated by his fingers [AP].
Strange things are afoot at the Tevatron particle collider at Fermilab, and the aging U.S. particle smasher is getting an unexpected moment in the spotlight while physicists wait for the repairs of the Large Hadron Collider in Switzerland. Researchers say experiments at the Tevatron have produced particles that they are unable to explain using the standard model of physics, and say it’s possible that they’ve detected a previously unknown particle. If the result does turn out to be due to some unexpected new process, it would be the most significant discovery in particle physics for decades [Physics World].
Bloggers and theorists are already lining up explanations that involve unseen particles, hypothetical strings, or modifications of conventional physics. The finding is so controversial that about one-third of the 600-person experiment that detected it are refusing to put their names on the 69-page paper purporting its discovery [Nature News], which was posted in advance of publication on the server arXiv.
Scientists at CERN had said all along that they planned to activate the Larger Hadron Collider this summer. Now it looks like they’ll slide in just before the official end of the season. The world’s most powerful particle accelerator, aimed at unlocking secrets of the universe, will be launched on September 10 [Reuters].
“We’re finishing a marathon with a sprint,” said project leader Lyn Evans. “It’s been a long haul, and we’re all eager to get the LHC research program under way” [San Jose Mercury News].
Well, that’s a relief. After a long safety review, physicists have declared that the enormous atom smasher that’s expected to go online this fall won’t create tiny black holes that will “eat” our planet. So that’s one less thing to worry about.
The Large Hadron Collider, which is being built near Geneva, Switzerland, will do things with subatomic particles that humans have never done before, causing some people to worry that scientists might be unwittingly building a doomsday devise. The $8 billion machine is designed to accelerate protons, the building blocks of ordinary matter, to energies of 7 trillion electron volts and then bang them together to produce tiny primordial fireballs, miniature versions of the Big Bang. Physicists will comb the detritus from those fireballs in search of forces and particles and even new laws of nature that might have prevailed during the first trillionth of a second of time [The New York Times].