Starts With A Bang

Ask Ethan: Could the Universe be a simulation? (Synopsis)

IBM's Four Qubit Square Circuit, a pioneering advance in computations, could lead to computers powerful enough to simulate a Universe. Image credit: IBM research.

“Do I believe, for example, that by using magic I could fly? No. How would you get around gravity? Impossible. Do I believe that I might be able to project my consciousness into a very, very vivid simulation of flying? Yeah. Yes, I’ve done that. Yes, that works.” -Alan Moore

If you possessed a computer with enough power, you could conceivably simulate the entire Universe. From the inception of the Big Bang, you could compute the positions and momenta of every particle and every interaction over time, across all 13.8 billion years. If your simulation was good enough, you could even account for quantum processes and uncertainty, and you’d wind up with planets, life, and even human brains at the end.

Certain correlations or physical observations could be indicators of a simulated Universe, but many assumptions remain uncertain. Image credit: pixabay user insspirito.

But if this were representative of our reality, would there be any way to tell? Maybe computational short-cuts would show up as some sort of fundamental blurriness at small enough scale. And what would that tell us about our quest to understand the fundamental constants, particles and interactions that define our Universe? Would it all be futile? Perhaps there would still be something important to learn about our existence by asking the right fundamental questions through experiments.

One of the tubes of the GEO600 detectors, which looked for the blurring of signals consistent with our Universe being a simulation. No blurring was found. Image credit: Max Planck Institute for Gravitational Physics/Leibniz Universität Hannover.

This was a hot topic earlier this year, and thanks to Rudy Kellner and Samir Kumar, it’s the subject of this week’s Ask Ethan!