By P.Vishnupraneeth Reddy

Edited by Nidhi Singh, Junior Editor

Tests could reveal whether we are part of a giant computer simulation—but the real question is if we want to know…In the 1999 sci-fi film classic The Matrix, the protagonist, Neo, is stunned to see people defying the laws of physics, running up walls and vanishing suddenly. These superhuman violations of the rules of the universe are possible because, unaware to him, hero’s consciousness in the film is embedded in the Matrix, a virtual-reality simulation created by sentient machines. Physicists can now offer us the same choice, the ability to test whether we live in our own virtual Matrix, by studying radiation from space. As fanciful as it sounds, some philosophers have deeply argued that we’re actually more likely to be artificial intelligences trapped in a fake universe than we are organic minds in the “real” one. But if that were true, the very laws of physics that allow us to devise such reality-checking technology may have little to do with the fundamental rules that govern the meta-universe inhabited by our simulators. To us, these programmers would be gods, able to twist reality on a whim.

The first serious attempt to find the truth about our universe came in 2001, when an effort to calculate the resources needed for a universe-size simulation made the prospect seem impossible. Seth Lloyd, a quantum-mechanical engineer at MIT, estimated the number of “computer operations” our universe has performed since the Big Bang — basically, every event that has ever happened. To repeat them, and generate a perfect facsimile of reality down to the last atom, would take more energy than the universe has. “The computer would have to be bigger than the universe, and time would tick more slowly in the program than in reality,” says Lloyd.

But others soon realized that making an imperfect copy of the universe that’s just good enough to fool its inhabitants would take far less computational power. In such a makeshift cosmos, the fine details of the microscopic world and the farthest stars might only be filled in by the programmers on the rare occasions that people study them with scientific equipment. As soon as no one was looking, they’d simply vanish. In theory, we’d never detect these disappearing features, however, because each time the simulators noticed we were observing them again, they’d sketch them back in. That realization makes creating virtual universes eerily possible, even for us. Today’s supercomputers already crudely model the early universe, simulating how infant galaxies grew and changed. Given the rapid technological advances we’ve witnessed over past decades — your cell phone has more processing power than NASA’s computers had during the moon landings — it’s not a huge leap to imagine that such simulations will eventually encompass intelligent life.

Last year, Professor Beane of Cambridge University and his colleagues suggested a more concrete test of the simulation hypothesis. Most physicists assume that space is smooth and extends out infinitely. But physicists modeling the early universe cannot easily re-create a perfectly smooth background to house their atoms, stars and galaxies. Instead, they build up their simulated space from a lattice, or grid, just as television images are made up from multiple pixels. The team calculated that the motion of particles within their simulation, and thus their energy, is related to the distance between the points of the lattice: the smaller the grid size, the higher the energy particles can have. The simulation’s lattice has another observable effect that astronomers could pick up. If space is continuous, then there is no underlying grid that guides the direction of cosmic rays — they should come in from every direction equally. If we live in a simulation based on a lattice, however, the team has calculated that we wouldn’t see this even distribution.

Unfortunately, our almighty simulators may instead have programmed us into a universe-size reality show — and are capable of manipulating the rules of the game, purely for their entertainment. In that case, maybe our best strategy is to lead lives that amuse our audience, in the hope that our simulator-gods will resurrect us in the afterlife of next-generation simulations. The weird consequences would not end there. Our simulators may be simulations themselves — just one rabbit hole within a linked series, each with different fundamental physical laws. “If we’re indeed a simulation, then that would be a logical possibility, that what we’re measuring aren’t really the laws of nature, they’re some sort of attempt at some sort of artificial law that the simulators have come up with.” Says Mr. Beane. This cosmic ray test may help reveal whether we are just lines of code in an artificial Matrix, where the established rules of physics may be bent, or even broken. But learning that truth means accepting that you may never know for sure what’s real — including yourself.

P.Vishnupraneeth is studying at the Indian Institute of Technology at Guwahati, India, an Institute of National Importance. He is pursuing his undergraduate studies in ECE & Physics departments simultaneously. Apart from his engineering side, his interest lies in writing articles about sports, special ops around the world, war, politics & their consequences on economy, Income tax etc. His favourite writers are Rabindranath Tagore & APJ Abdul Kalam.

Posted by The Indian Economist | For the Curious Mind