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THE ENERGY OF EMPTY SPACE THAT ISN'T ZERO [LAWRENCE KRAUSS:] I just returned from the Virgin Islands, from a delightful event — a conference in St. Thomas — that I organized with 21 physicists. I like small events, and I got to hand-pick the people. The topic of the meeting was "Confronting Gravity. " I wanted to have a meeting where people would look forward to the key issues facing fundamental physics and cosmology. And if you think about it they all revolve in one way or another around gravity. Someone at the meeting said, well, you know, don't we...

Newswise — Researchers at Northeastern University and the University of California, Irvine say that scientists might soon have evidence for extra dimensions and other exotic predictions of string theory. Early results from a neutrino detector at the South Pole, called AMANDA, show that ghostlike particles from space could serve as probes to a world beyond our familiar three dimensions, the research team says. No more than a dozen high-energy neutrinos have been detected so far. However, the current detection rate and energy range indicate that AMANDA's larger successor, called IceCube, now under construction, could provide the first evidence for string...

Tuesday, Apr 12, 2005 A century after Albert Einstein published his most famous ideas, physicists commemorated the occasion by trying to demolish one of them. Yesterday astronomers were to tell experts gathering at Warwick University in England to celebrate the anniversary of the great man's "miracle year" that the speed of light -- Einstein's unchanging yardstick that underpins his special theory of relativity -- might be slowing down. Michael Murphy, of the Institute of Astronomy at Cambridge University, said: "We are claiming something extraordinary here. fundamental "The findings suggest that there is a more fundamental theory of the way that...

Could two lookalike galaxies, barely a whisker apart in the night sky, herald a revolution in our understanding of fundamental physics? Some physicists believe that the two galaxies are the same - its image has been split into two, they maintain, by a "cosmic string"; a San Andreas Fault in the very fabric of space and time. If this interpretation is correct, then CSL-1 - the name of the curious double galaxy - is the first concrete evidence for "superstring theory": the best candidate for a "theory of everything", which attempts to encapsulate all the phenomena of nature in one...

stronomers have gazed out at the universe for centuries, asking why it is the way it is. But lately a growing number of them are dreaming of universes that never were and asking, why not? Why, they ask, do we live in 3 dimensions of space and not 2, 10 or 25? Why is a light ray so fast and a whisper so slow? Why are atoms so tiny and stars so big? Why is the universe so old? Does it have to be that way, or are there places, other universes, where things are different? Once upon a time...

The proof that faster-than-light (FTL) propagation is not allowed by nature is simple. Special relativity (SR) forbids it because, in that theory, time slows and approaches a cessation of flow for any material entity approaching the speed of light. So no matter how much energy is brought to bear, the entity cannot be propelled all the way to, much less beyond, the point where time ceases. The entity’s inertia simply increases towards infinity as the speed barrier is approached.[*] But most importantly, relativists are confident that SR is a valid theory because it has passed eleven independent experiments confirming most...

Is string theory the answer to the last big questions in physics, or a dead end? While some physicists believe that string theory could lead to a unifying 'theory of everything,' detractors say that string theory is sloppy and founded on unwarranted assumptions. One new book calls string theory 'not even wrong.' In this hour of Science Friday, we'll look at the pros and con of string theory, with physicists Lee Smolin and Brian Greene.

Scientists use quantum gravity to describe the universe before the Big Bang.Scientists may finally have an answer to a "big" question: If the Big Bang was the beginning of the universe, what could have caused it to happen? Using a theory called "loop quantum gravity," a group led by Penn State professor Abhay Ashtekar has shown that just before the Big Bang occurred, another universe very similar to ours may have been contracting. According to the group's findings, this previous universe eventually became so dense that a normally negligible repulsive component of the gravitational force overpowered the attractive component, causing...

One universe or many? Panel holds unusual debate March 30, 2006 Special to World Science Scientific debates are as old as science. But in science, “debate” usually means a battle of ideas in general, not an actual, politician-style duel in front of an audience. Occasionally, though, the latter also happens. And when the topic is as esoteric as the existence of multiple universes, sparks can fly. According to one proposal, new universes could sprout like bubbles off a spacetime "foam" that's not unlike soap bubbles. (Courtesy Lawrence Berkeley National Laboratory) Such was the scene Wednesday evening at the American Museum...

Exclusive from New Scientist Hidden extra dimensions are causing measurements of the strength of gravity at different locations on Earth to be affected by the planet's magnetic field, French researchers say. This is a controversial claim because no one has ever provided experimental evidence to support either the existence of extra dimensions or any interaction between gravity and electromagnetism. But lab measurements of Newton's gravitational constant G suggest that both are real. Newton's constant, which describes the strength of the gravitational pull that bodies exert on each other, is the most poorly determined of the constants of nature. The two...

Quantum physics predicts the existence of an underlying sea of zero-point energy at every point in the universe. This is different from the cosmic microwave background and is also referred to as the electromagnetic quantum vacuum since it is the lowest state of otherwise empty space. This energy is so enormous that most physicists believe that even though zero-point energy seems to be an inescapable consequence of elementary quantum theory, it cannot be physically real, and so is subtracted away in calculations. A minority of physicists accept it as real energy which we cannot directly sense since it is the...

The recent ruling in Dover, Pa., against the mention of intelligent design in biology textbooks was a small cultural victory for science - not because intelligent design posed a genuine threat to the theory of evolution, but because the decision showed the public that there is an important difference between science and pseudoscience. In the wake of the trial, scientists are being criticized, even by their own colleagues, for working on anything that might be construed as pseudoscience - and string theory is drawing most of the heat. An intense controversy has erupted regarding the status of this potential "theory...

Supersymmetry and Parallel Dimensions Harvard Physicst Randall among world’s leading string theorists Published On Friday, January 06, 2006  1:00 AM By ADRIAN J. SMITH Crimson Staff Writer Professor of Physics Lisa Randall ’83, recently named one of Newsweek’s most influential people of 2006, rose to the top with her theories on gravity. (Photo credit: CRIMSON/GLORIA B. HO) Professor of Physics Lisa Randall ’83 saw how strong gravity could be during a climbing fall in New Hampshire two years ago. She was performing a “challenging” move when she took a surprising fall, she says. Instead of stopping the fall, her support...

Many high-profile critics in the raging debate over "intelligent design" have, understandably, been evolutionary biologists. Legendary Oxford professor Richard Dawkins regularly appears on British TV to talk up Darwin and lash out against ID between books. Harvard emeritus prof E.O. Wilson has edited a hefty new 1,700-page anthology of Darwin's collected works, with the fighting title From So Simple a Beginning. They're generally not people like Leonard Susskind, a renowned physics professor at Stanford and a prime architect of string theory. His new book, his first for a general audience, has the provocative title The Cosmic Landscape: String Theory and...

Why are physicists taking the idea of multiple universes seriously now? First, there was the discovery in the past few years that inflation seems right. This theory that the universe expanded spectacularly in the first fraction of a second fits a lot of data. Inflation tells us that the universe is probably extremely big and necessarily diverse. On sufficiently big scales, and if inflation lasts long enough, this diversity will produce every possible universe. The same process that forged our universe in a big bang will happen over and over. The mathematics are rickety, but that's what inflation implies: a...

My "Swirl Theory"We hear of string theory, the Big Bang and many other ideas.I have come up with this idea over the past several days. Katrina and Rita has turned my attention towards this as I have discovered a new theory as of late that black holes may be present at the center of each galaxy.Using the theory that a black hole could have possibly been created in space by gases which collapsed into itself churning and sucking gasses and space debris around it into a swirling vortex. This swirling vortex of gas eventually condensed into planets and solar systems.Here...

The Good and Bad of String Theory The most celebrated theory in modern physics faces increasing attacks from skeptics who fear it has lured a generation of researchers down an intellectual dead end. In its original, simplified form, circa the mid-1980s, string theory held that reality consists of infinitesimally small, wiggling objects called strings, which vibrate in ways that yield the different subatomic particles that comprise the cosmos. Advocates claimed that string theory would smooth out the conflicts between Einsteinian relativity and quantum mechanics and the result would be a unifying "theory of everything," which could explain everything from...

'Theory of everything' tying researchers up in knots- Keay Davidson, Chronicle Science Writer Monday, March 14, 2005 The most celebrated theory in modern physics faces increasing attacks from skeptics who fear it has lured a generation of researchers down an intellectual dead end. In its original, simplified form, circa the mid-1980s, string theory held that reality consists of infinitesimally small, wiggling objects called strings, which vibrate in ways that yield the different subatomic particles that comprise the cosmos. An analogy is the vibrations on a violin string, which yield different musical notes. Advocates claimed that string theory would smooth out...

Issue 107 / February 2005 Escape from the universe The universe is destined to end. Before it does, could an advanced civilisation escape via a "wormhole" into a parallel universe? The idea seems like science fiction, but it is consistent with the laws of physics and biology. Here's how to do it Michio KakuThe author is professor of theoretical physics at City University of New York. This article is adapted from his book "Parallel Worlds" (Allen Lane) The universe is out of control, in a runaway acceleration. Eventually all intelligent life will face the final doom—the big freeze. An advanced...

String fellows100 years after Einstein changed physics for ever, Alok Jha visits a leafy corner of Princeton to meet his intellectual heirs - still hunting for a theory of everythingAlok JhaThursday January 20, 2005GuardianEdward Witten is so softly spoken that his voice sometimes threatens to drift away completely. His desk is a jumble of papers and his blackboard a mess of equations. But his hushed words come straight to the point and are infused with understanding and passion.Witten's quiet manner belies his status. In his role as de facto scientist-in-chief of string theory, Witten, the Charles Simonyi professor of mathematical...