Is the Universe Real?

Rethinking the idea that makes you rethink reality

Illustration: Zoë Van Dijk

Three years ago, the American Museum of Natural History in New York hosted a debate that has since been watched 2.1 million times on YouTube. Four physicists and a philosopher, prodded by moderator Neil deGrasse Tyson, spent two hours discussing whether reality as we know it might be a simulation.

If it is, we’re all characters in a computer-generated world that is so dense with data, so abundant in processing power, that it gives rise to our very consciousness. It wouldn’t necessarily mean we’re being manipulated by a master simulator. That entity might have established the laws of nature as we perceive them and then hit “go” to see what would evolve. Regardless of the specifics, it would mean our universe is being or was originally rendered from some other plane — from the actual “base reality.”

This hypothesis wasn’t new in 2016, but something about that New York debate was compelling, and it was covered in several science publications. Geek high priests like Elon Musk have since claimed that we’re very likely to be in a simulation, bestowing a sheen on the idea for its enthusiasts and potential converts. Meanwhile, even if you find the simulation idea ridiculous — I probably should disclose that I’m in this camp — it can be stimulating to hear how someone concludes that the hypothesis is not merely conceivable, but actually plausible.

At the end of the night, Tyson asked each of the five panelists to blurt out “the likelihood that you think we are in a simulation.” The highest of the numbers came from the philosopher in the group, David Chalmers of NYU, who said, dryly, “42 percent” — a joke from The Hitchhiker’s Guide to the Galaxy. Max Tegmark, a physicist at MIT, said 17 percent, which is roughly the chance that you’ll get the specific number you want when you roll a die. Jim Gates, who is now at Brown University, said 1 percent. Lisa Randall of Harvard, who had earlier said she wondered why people consider the simulation hypothesis an interesting question, said the chances of it being correct were “effectively zero.” Unfazed, Tyson said he suspected that “the likelihood may be very high.”

The only panelist who wouldn’t give any odds was Zohreh Davoudi, a theoretical physicist now at the…