physics Archives - Tachyon Publications

January 12, 2016

A Radical Reinterpretation of Einstein’s Theory

Alec Checkerfield Uncategorized albert einstein, dan faulk, george musser, julian barbour, nova, nova next, pbs, physics, science, sean gryb, shape dynamics, theory of relativity

The shape of an object is a real, objective quality according to the theory of shape dynamics.

Photo: Jonathan/Flickr (CC BY-NC-ND)

For NOVA NEXT, Dan Falk writes about physicist Julian Barbour and his colleagues attempts to change the way “we view as the fundamental elements of reality.”

For Julian Barbour, those musings most often involve the nature of space and time. Barbour, 78, is an independent physicist who contemplates the cosmos from College Farm, a rustic thatched-roof country house some twenty miles north of Oxford. He is perhaps best known for his 1999 book The End of Time: The Next Revolution in Physics, in which he argues that time is an illusion.

While country walks may be best enjoyed on one’s own, musings about theoretical physics can benefit from good, smart company—and Barbour has made a point of inviting a handful of bright young physicists to join him for periodic brainstorming sessions at College Farm—think Plato’s Academy in the English countryside.

Photograph of Julian Barbour by George Musser

Their latest offering is something called “shape dynamics.” (If you’ve never heard of shape dynamics, that’s OK—neither have most physicists.) It could, of course, be a dead end, as most bold new ideas in physics are. Or it could be the next great revolution in our conception of the cosmos. Its supporters describe it as a new way of looking at gravity, although it could end up being quite a bit more than that. It appears to give a radical new picture of space and time—and of black holes in particular. It could even alter our view of what’s “real” in the universe.

Last summer, Barbour and his colleagues gathered for a workshop at the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, to hash out the ideas behind shape dynamics. During a break in the workshop, I sat down with a young physicist named Sean Gryb, one of Barbour’s protégés.

“We’re trying to re-evaluate the basic assumptions of Einstein’s theory of relativity—in particular, what it has to say about gravity,” Gryb says. “It’s a shift in what we view as the fundamental elements of reality.”

Read the rest of Falks fascinating article at NOVA NEXT.

December 9, 2015

The Holometer challenges our assumptions about space and time

Alec Checkerfield Uncategorized aaron chou, astrophysics, brittany kamai, craig hogan, fermilab, holometer, physics, science

A member of the Holometer collaboration works on the sensitive space-time measuring device, located at Fermilab in Illinois. Photo: Fermilab

On their official page, the Fermilab has announced that “there has never been anything like the Holometer.”

Based at the U.S. Department of Energy’s Fermilab in Illinois, the Holometer isn’t much to look at. It’s a small array of lasers and mirrors with a trailer for a control room. But the low-tech look of the device belies the fact that it is an unprecedentedly sensitive instrument, able to measure movements that last only a millionth of a second and distances that are a billionth of a billionth of a meter – a thousand times smaller than a single proton.

Our common sense, and the laws of physics, assumes that space and time are continuous. The Holometer challenges this assumption. We know that energy on the atomic level, for instance, is not continuous and comes in small, indivisible amounts. The Holometer was built to test if space and time behave the same way.

Aaron Chou, project manager of the Holometer, and grad student Brittany Kamai work on the laser beam that powers the Holometer. Photo: Fermilab.

The main theory the Holometer was built to test was posited by Craig Hogan, a professor of astronomy and physics at the University of Chicago and the head of Fermilab’s Center for Particle Astrophysics. In a new result released this week after a year of data-taking, the Holometer collaboration has announced that it has ruled out Hogan’s theory of a pixelated universe to a high level of statistical significance. This means the Holometer did not detect the amount of correlated holographic noise – quantum jitter – that this particular model of space-time predicts.

But as Hogan emphasizes, that’s just one theory, and with the Holometer, this team of scientists has proven that space-time can be probed at an unprecedented level.

“This is just the beginning of the story,” Hogan said. “We’ve developed a new way of studying space and time that we didn’t have before. We weren’t even sure we could attain the sensitivity we did.”

For more about the Holometer and the science involved, visit the Fermilab site.

A scientist works on the laser interferometer at the heart of the Holometer experiment. Photo: Fermilab.

August 28, 2015

Black holes don’t actually swallow and destroy physical information

Alec Checkerfield Uncategorized astronomy, black holes, hawking radiation conference, kth royal institute of technology, laura mersini-houghton, physics, science, stephen hawking

Stephen Hawking revealed his latest idea about where he believes lost information winds up after being sucked into a black hole — in alternative universes. Photo: Adam af Ekenstam

At the recent Hawking Radiation Conference, Stephen Hawking’s new idea about what happens to information trapped in black holes dominated the discussion.

Black holes don’t actually swallow and destroy physical information, according to an idea Hawking proposed at the Hawking Radiation conference. Instead, they store it in a two-dimensional hologram, and then it gets severely jumbled up.

You might ask yourself why this distinction matters, but it addresses one of the most baffling questions facing a generation of physicists: What happens to the information about the physical state of things that are swallowed up by black holes? Is it destroyed, as our understanding of general relativity would predict?

If so, that would violate the laws of quantum mechanics. So, which theory of physics is right? Hawking’s answers appears to be they both are.

Stephen Hawking makes his presentation to a gathering of world-leading physicists at KTH Royal Institute of Technology. (Photo: Håkan Lindgren)

The day before the conference’s start, Hawking posited a controversial theory about the subject.

“The existence of alternative histories with black holes suggests this might be possible,” Hawking said. “The hole would need to be large and if it was rotating it might have a passage to another universe. But you couldn’t come back to our universe. So although I’m keen on space flight, I’m not going to try that.

“The message of this lecture is that black holes ain’t as black as they are painted. They are not the eternal prisons they were once thought. Things can get out of a black hole both on the outside and possibly come out in another universe.”

Hosted by KTH Royal Institute of Technology, the Hawking Radiation Conference was called by Laura Mersini-Houghton, a theoretical physicist at the University of North Carolina (UNC).

Stephen Hawking and some three dozen of the world’s most influential physicists will convene on KTH’s campus to seek a solution to a puzzle that has vexed science for years: whether singularities actually exist in black holes, and whether Hawking Radiation has any bearing on their existence.

For more about the Hawking Radiation Conference, visit the KTH Royal Institute of Technology page.

July 2, 2015

The universe we live in might be a hologram

Alec Checkerfield Uncategorized fact, holographic principle, joseph stromberg, physics, science, science fact, tu wien, vox

(TU Wien)

Over at VOX, Joseph Stromberg explains how the universe we live in might be a hologram.

Some physicists actually believe that the universe we live in might be a hologram.

The idea isn’t that the universe is some sort of fake simulation out of THE MATRIX, but rather that even though we appear to live in a three-dimensional universe, it might only have two dimensions. It’s called the holographic principle.

The thinking goes like this: Some distant two-dimensional surface contains all the data needed to fully describe our world — and much like in a hologram, this data is projected to appear in three dimensions. Like the characters on a TV screen, we live on a flat surface that happens to look like it has depth.

It might sound absurd. But if when physicists assume it’s true in their calculations, all sorts of big physics problems — such as the nature of black holes and the reconciling of gravity and quantum mechanics — become much simpler to solve. In short, the laws of physics seem to make more sense when written in two dimensions than in three.

Read the rest of Stromberg’s fascinating article at VOX.

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