Six Lines

Google's Quantum Computing Breakthrough

Posted by Aaron Massey on 25 Oct 2019.

Google’s purported and now realized quantum computing breakthrough has dominated much of my news cycle this past week. And despite being months and months behind in my goal to share things that make me happy, I thought I would share something about this breakthrough. (You can access the academic paper on Nature.)

The most basic question people have about this is simple: How big of a deal is it? And the answer here is hard to state. It’s an important milestone, but I think it’s hard to claim much more than that. This doesn’t immediately change the world of computing, let alone the non-computing world. It’s just another critical step on the long path towards realizing the potential of quantum physics for computing. We’re still decades away from practical quantum computers that “anyone” can access.

That said, this still makes me happy in a fundamental way. It’s amazing that computers are possible, that we can program them to do so many useful things for us. They are so common now that it’s easy to look past the small miracles of the physics and math that make computers what they are, whether classical or quantum. And this is one of the few moments when even non-computing professionals might get a taste of that magic.

Here’s one example from CNET of how that might work, which includes an opportunity to correct Richard Feynman:

Feynman made this last point back in 1981. “Nature isn’t classical, dammit, and if you want to make a simulation of nature, you’d better make it quantum mechanical,” he said in a speech at MIT. You can approximate nature with a simulation on a classical computer, but Feynman wanted a quantum computer that offers the real thing, a computer that “will do exactly the same as nature,” Feynman said.

First, the insight here is exactly what I hope people take from the Google quantum computing story. There’s a better model of nature than what classical computers can do, so if we’re going to improve, then we have to go quantum. Google’s breakthrough is a necessary step in that journey.

Second, the correction! Feynman is wrong to claim that quantum computing is “exactly” what nature would do. Quantum physics are demonstrably more accurate than classical physics, but they are both still models. We don’t have answers to all the questions quantum physics raises about how nature works, so it’s silly to suggest that this is “exactly” how nature works. It’s still, after all, just a model of nature that seems to fit really well. I think, ultimately, Feynman would have known this, and I mostly blame Stephen Shankland, the author of the CNET piece, for positioning Feynman’s quote in this way. Of all the philosophical mistakes I’ve seen scientists make, this is a rather minor one that is probably more misspeaking than an actual mistake. But still, it’s fun to think that I’m correcting Feynman, even if he was ultimately misrepresented in the first place.