The Measurement That Would Reveal The Universe As A Computer Simulation - Technology Review

The Measurement That Would Reveal The Universe As A Computer Simulation - Technology Review: The question that Beane and co ask is whether the lattice spacing imposes any kind of limitation on the physical processes we see in the universe...

They say that the lattice spacing imposes a fundamental limit on the energy that particles can have. That's because nothing can exist that is smaller than the lattice itself.

So if our cosmos is merely a simulation, there ought to be a cut off in the spectrum of high energy particles...


"The most striking feature...is that the angular distribution of the highest energy components would exhibit cubic symmetry in the rest frame of the lattice, deviating significantly from isotropy," they say.

Proof Found for Unifying Quantum Principle

Proof Found for Unifying Quantum Principle: His conjecture is called the a-theorem. It says that the number of ways in which quantum fields can be energetically excited (a) is always greater at high energies than at low energies...

Although lots of work has gone into relating short- and long-distance scales for particular quantum field theories, there are relatively few general principles that do this for all theories that can exist...
But Cardy's a-theorem could be one such principle. A version of it had already been proven in two dimensions, but Cardy proposed that it might hold in four dimensions--such as the three dimensions of space and one of time that exist in the space in which we live.

Hologram revolution: The theory changing all physics - physics-math - 13 July 2011 - New Scientist

Hologram revolution: The theory changing all physics: Leonard Susskind of Stanford University in California, one of the original architects of the holographic principle, describes the duality as the "new orthodoxy". Skenderis is convinced that we are only just beginning to see its potential. "If we look forward to 50 years from now, we will see this period as a precursor to a time when physics is totally reformulated in the language of holography," he says. "Once the theory is properly fleshed out, we will be able to apply it to almost any problem."

Proton puzzle: Trouble at the heart of the atom - physics-math - 30 March 2011 - New Scientist

Proton puzzle: Trouble at the heart of the atom: Measuring the muons' orbital energy levels meant first guessing the gaps between the two levels of interest, so a laser could be tuned to the right frequency to bump a muon from one level to another. The team did this by reversing the QED equations and plugging in the accepted value for the proton's radius to give an estimated starting point.

In the first couple of attempts to run the full experiment, in 2003 and 2007, that approach didn't work: the muons did not respond. It was only in 2009, when the team had a new laser that could reach higher frequencies, that they found the muons' sweet spot and persuaded them to dance. Feeding the experimentally determined energy levels back into the QED calculation produced the shocker. The error on the proton's radius had shrunk by a factor of 10, as expected - but the radius had shrunk too. At 0.8418 femtometres, it was about 4 per cent lower than the previous average...

Why the early universe was free of charge - space - 04 November 2010 - New Scientist

Why the early universe was free of charge: In 2006, Wilczek and Sean Robinson, both at the Massachusetts Institute of Technology, showed that the electromagnetic force also weakens at higher energies, but only in the presence of gravity, which is neglected in the standard model (Physical Review Letters, DOI: 10.1103/PhysRevLett.96.231601). Others punched holes in their calculations, however, and so the idea remained controversial. "We tried to do it without going through the heavy formal mathematics," Wilczek says.

Now David Toms of Newcastle University in the UK has redone the calculations more rigorously and come up with the same conclusions. In the presence of gravity, electric charge - a barometer of the strength of the electromagnetic force - tends to go to zero as energies rise (Nature, DOI: 10.1038/nature09506). "With no gravity, the electric charge gets bigger [with higher energies]," says Toms. "Gravity changes the picture."

Void that is truly empty solves dark energy puzzle - physics-math - 01 September 2010 - New Scientist

Void that is truly empty solves dark energy puzzle: "People have just been taking it on faith that this quark condensate is present throughout the vacuum," says Brodsky. Instead, his team have assumed that the condensate exists only inside protons, neutrons, pions and all other quark-containing particles, collectively known as hadrons (Physical Review C, DOI: 10.1103/PhysRevC.82.022201).

"In our picture, quarks and gluons can't flutter in and out of existence unless they are inside hadrons," says team member Craig Roberts of the Argonne National Laboratory in Illinois. As a result, the vacuum is much calmer and, crucially, the problem it poses for the cosmological constant is reduced.

n 1974, Aharon Casher of Tel Aviv University in Israel and Leonard Susskind, now at Stanford University in California, suggested that a condensate present only inside hadrons could give these particles mass. Brodsky and colleagues are the first to show that this idea also helps resolve the dark energy discrepancy.