Holy matrix! In other words, he’s suggesting that what happens in these models, which exist only as computations, is as valid as phenomena in what we call the real world–even though these model universes are spectacularly less complex than the actual universe. (Even building his simulations with a 100-core network he has access to as the CEO of a company can’t begin to approach the computation invested in the real universe, which Wolfram guesses might have run its basic rule something like 10400 iterations to get, well, everything.)
Nonetheless, Wolfram says he has been able to discover the same equations operating in these models as the ones we use to prove theories like quantum mechanics or gravity in the real world.
“We started to prove various general properties of these models,” says his 22-year-old collaborator Gorard, who is a PhD candidate at Cambridge. “By making just simple constraints on the rules, we were able to get out phenomena that we could show was analogous to–or in some cases equivalent to–things we know about in real physics.” By this, he means things like the cornerstones of physics: general relativity and quantum field theory.
But so far none of the universes have viable candidates for the one Wolfram wants most to produce: the single rule that’s the one that our universe runs.
Do I even need to bother mentioning that Wolfram’s approach isn’t exactly the way physics is practiced these days? Though his early adoption of the computational paradigm of physics has proved prescient, there have always been sharp critics of his unconventional approach, most notably the celebrated Freeman Dyson, who died in February. “I’m not sure that what he does can be called science,” Dyson told me when he was a colleague of Wolfram’s at the Institute of Advanced Study. When NKS came out, Dyson said it was “worthless.” (Wolfram now tells me that a few months ago, he asked Dyson if the quotes about him were accurate. Dyson verified that they were. “I still have the email exchange where he said, ‘Well, yes, I said that–and I still think all the stuff you’ve done is nonsense!” Wolfram tells me.)
Wolfram understands that his project is likely to draw more interest from computer scientists than traditional physicists at first. “What I’ve told Stephen is that the people who work on computing will probably find this incredibly compelling,” says Nathan Myhrvold, the CEO of Intellectual Ventures who, in a former life, was a particle physicist working with Stephen Hawking. “And more traditional fundamental physicists will probably say, ‘OK, great. You’ve used an unusual formalism to prove something we already knew.'” (Myhrvold does think that Wolfram’s work on the physics project is “intriguing.”)
And when I asked Jonathan Gorard what his physics professors thought of his work with Wolfram, he admitted that many were “apathetic.” On the other hand, he said, “Gratifyingly, no one has completely shut it down and said, ‘This is totally crazy. You’re nuts.’ Or whatever.”
But not all of the establishment writes off Wolfram. Andrew Strominger, the Gwill E. York professor of physics at Harvard University and a leading string theorist, wrote in an email that there is a need for new concepts and tools to solve long-standing problems in physics. “Stephen is addressing these issues with a radically new approach,” he wrote. “It has been stimulating to discuss these issues with him, and I am excited to see where it will lead.”
After an admittedly brief look at Wolfram’s materials, the prominent physicist Sean Carroll also showed interest, while expressing reservations. “On the one hand, I’m in favor of taking swings at fundamental physics with wildly nonstandard ideas and seeing what happens,” says Carroll, a research professor of physics at Caltech. “Most such efforts will inevitably fail, but the payoff is huge if you hit the target. On the other hand, the standard procedure in the development of such ideas would be to verify that you can recover some simple cases of known physics–the simple harmonic oscillator, the inverse-square law for gravity, the double-slit experiment–before raising hopes for a fundamental theory of everything.” (“Of course we’ve done that,” says Wolfram.)