Michael Nielsen – Why aliens will have a different tech stack than us

Today I'm speaking with Michael Nielsen. You have done many things. You're one of the pioneers of quantum computing, wrote the main textbook in the field of the open science movement. You wrote a book about deep learning that Chris Olah and, uh, Greg Brockman credit them with getting them into the field. Um, more recently, you're a research fellow at the Astera Institute and writing a book about religion, science, and technology. I'm gonna ask you about none of those things. The conversation I wanna have today is, how do we recognize scientific progress? And it's, it's es-especially relevant, uh, for AI because people are trying to close the RL verification loop on scientific discovery.

Mm-hmm.

And what does it mean to close that loop? But in preparing for this interview, I've realized that it's a more mysterious and elusive, um, force even in the history of human science than I understood. And I think a good place to start will be Michelson-Morley and how special relativity is discovered, if it's different than the story that you kind of get off of YouTube videos. Um, anyways, I, I will prompt you that way, and then we'll go in there.

Okay. Yeah, so, I mean, Michelson-Morley is, uh, one of the sort of the, the, the famous results often presented as, as this, this experiment that was done in the 1880s and that helped Einstein, you know, come up with the, the special theory of relativity a little bit later. So, so sort of changing our, our... the way we think about space and, and time and, and our fundamental conception of those things. Um, and there's kind of a, uh, a big gap, I think, between the way Michelson and Morley and other people at the time thought about the experiment and certainly the way in which, uh, Einstein thought or did not think about the experiment. Um, uh, in actual fact, he, uh, uh, stated later in his life he wasn't even sure whether he was aware of the paper at the time. Um, there's a lot of evidence that he, he probably was aware of the paper at the time, but it actually wasn't dispositive for his thinking at all. Uh, something else, uh, completely was, was, was going on. Um, so, uh, uh, what Michelson and Morley thought they were doing was they thought they were testing different theories of, of what was called the ether. So as you go back to the, the, the 1600s, uh, Robert Boyle introduced the idea of the ether, and basically the idea of the ether is, um, you know, we know that, that sound is vibrations in the air. Um, and then Boyle and other people got interested in the question of, like, is, is light vibrations, uh, in something, and they couldn't figure out, uh, what it was. Boyle actually did an experiment where he, he tested whether or not you could propagate light through a vacuum. He found that you could. You couldn't do it with, with, with sound. So he introduced this idea of the ether, and then for the next two hundred or so years, people had, uh, all these kind of conversations about, about what the ether was and what its nature was. And the Michelson and Morley experiment was really an experiment to test different theories of the ether, uh, against one another, um, and i-in particular to find out whether or not there was a so-called ether wind. So the idea was that the, the Earth is passing through, uh, maybe this ether wind, and if it is passing through, uh, the ether wind, sort of this background, um, and you, you shoot a light beam sort of parallel, uh, t-to the direction the ether wind is going in, it'll get accelerated a little bit. Um, and if it's being passed back, uh, sort of in the opposite direction, it'll get slowed down a little bit, and you should be able to, to see this in the results of interference experiments. And what they found, much to their surprise, um, I think, uh, was that in fact there was no ether wind, um, and that ruled out some theories of the ether but, but, but not all, and, and Michelson certainly continued to b- to believe in the ether.