Showing posts with label simulation scenario. Show all posts
Showing posts with label simulation scenario. Show all posts

Sunday, February 22, 2015

Are you living in a simulation? - Silas Beane (SETI Talks)



"Is the Cosmos a Vast Computer Simulation?" New Theory May Offer Clues

Professor Silas Beane, a theoretical physicist at the University of Bonn in Germany said that his group of scientists have developed a way to test the 'simulation hypothesis'--the idea that we may be living in a computer generated universe that has been debated by the greats of philosphy, from Plato to Descartes, who speculated that the world we see around us could be generated by an 'evil demon'. Plato wrote that reality may be no more than shadows in a cave but the human species, having never left the cave, may not be aware of it.

If the cosmos is a numerical simulation, there ought to be clues in the spectrum of high energy cosmic rays. Now more than two thousand years since Plato suggested that our senses provide only a weak reflection of objective reality, experts believe they have solved the riddle using mathetical models known as the lattice QCD approach in an attempt to recreate - on a theoretical level - a simulated reality. Lattice QCD is a complex approach that that looks at how particles known as quarks and gluons relate in three dimensions.

"We consider ourselves on some level universe simulators because we calculate the interactions of particles by basically replacing space and time by a grid and putting it in a box," said Beane. "In doing that we face lots of problems for instance the box and the grid size breaks Einstein's special theory of relativity so we know how to fix this in order to get physical predictions that are meaningful."

"We thought that if we make the assumption that the so-called simulators face some of the same problems that we do in terms of finite resources and so on then, if they are doing a simulation and even though their box size of course is enormous and the grid size can be very small, as long as the resources are finite then the box size will be finite, the grid size will be finite," Beane added. "And therefore at some level for instance there would be violations of Einstein's special theory of relativity."

According to MIT's Technology Review, "using the world's most powerful supercomputers, physicists have only managed to simulate tiny corners of the cosmos just a few femtometers across (A femtometer is 10^-15 metres.) That may not sound like much but the significant point is that the simulation is essentially indistinguishable from the real thing (at least as far as we understand it)."

Read more: http://www.dailygalaxy.com/my_weblog/2012/10/is-the-cosmos-a-vast-computer-simulation-new-theory-may-offer-clues.html

Tuesday, February 17, 2015

Constraints on the Universe as a Numerical Simulation

From the paper written by Silas R. Beane, Zohreh Davoudi, Martin J. Savage...



Observable consequences of the hypothesis that the observed universe is a numerical simulation performed on a cubic space-time lattice or grid are explored. The simulation scenario is first motivated by extrapolating current trends in computational resource requirements for lattice QCD into the future. Using the historical development of lattice gauge theory technology as a guide, we assume that our universe is an early numerical simulation with unimproved Wilson fermion discretization and investigate potentially-observable consequences. Among the observables that are considered are the muon g-2 and the current differences between determinations of alpha, but the most stringent bound on the inverse lattice spacing of the universe, b^(-1) >~ 10^(11) GeV, is derived from the high-energy cut off of the cosmic ray spectrum. The numerical simulation scenario could reveal itself in the distributions of the highest energy cosmic rays exhibiting a degree of rotational symmetry breaking that reflects the structure of the underlying lattice...

read the paper: http://arxiv.org/pdf/1210.1847v2.pdf