Why a theory of everything is probably far off and string theory likely wrong

Transcript

Transcribed by machine (Whisper) from the episode’s audio, so a word may be off here and there.

1. 1:21:44

   All right. So let's back up. I'm going to pitch. I wrote this book for Oxford, Einstein's Unfinished Dream. And Einstein's Unfinished Dream was to come up with a theory of everything. It was unfinished because, well, it's unfinished. And so the second part, the tagline of that book is practical progress towards a theory of everything with the emphasis on practical. Because when you read books about theories of everything, when you see podcasts, when you listen to YouTube videos, or whatever, they are often written by theorists. And theorists are, they're big idea people. They're very, very smart. But there's a pragmatism that is often missing in the sense that they say, well, super strings, look, you know, have these little vibrating things and wouldn't it be cool?

2. 1:22:31

   You know, but you got to get to the, do you know it? So let's pretend super string theory or something like it is correct. The energy scale at which that should occur is of order 10 to the 15 times higher, 10 to the 19 GeV. We can currently do things at 10 to the fourth GeV, give or take. So that is 10 to the 15. That's a quadrillion times higher energy. So what we are doing now is we are looking at the world with our very best measurements, and we are trying to project out a quadrillion times higher and figure out a theory that explains everything.

3. 1:23:12

   Now, I have this, I have a couple of analogies, but I like this. Suppose that you were some, you know, Joe Australopithecus two million years ago or something in Africa, wandering around somewhere in Kenya, right? You're about a meter in size. So you can walk a meter. Meter scale is like your scale. You can walk 10 meters in every direction. That's 30 feet. No problem. You can work a hundred meters, 300 feet. You can work a thousand meters. That's half a mile. You can work 10,000 meters. That's 60 miles. A hundred thousand meters is 10 to the 5th. And that's unlikely. But the distance that we need to go from what we can see...

4. 1:23:52

   to the plank scale. It's not 10 to the 5th, it's 10 to the 15th. So that means, in my analogy, think about this guy who's walking around Africa. Now, if he walks, you know, 100 feet or something, it looks a lot like what it is now. He can make a prediction about what he sees. And when he goes to that new place, it's probably going to be okay. But if he starts walking 500 miles east, well, he, walking around the center of Africa, has no concept of, for instance, the Indian Ocean.

5. 1:24:20

   He would never predict sperm whales or kraken. He would never predict what it's like the bottom of the ocean is. Going north, he's in Africa. He would never, ever have a clue about the Alps or Antarctica. Going even smaller distances, going a mile up, things wouldn't be very different. But if he goes 10 miles up, he wouldn't breathe and he'd freeze. If he goes 100 miles up, he would die. If he goes two miles down, he would roast.

6. 1:24:47

   the point being is we are like that australopithecus we have a realm that we can study and we can even predict to some validity what would happen if we go some distance away but the farther away we go the less and less our local prediction really represents the reality of those more distant times. And so basically his theory about the world would be totally bogus. So even if he had the best theory, his theory would not have anticipated the Alps. It would not have anticipated penguins, flamingos, not there, you know, and that is just the case. So now that's what we're doing. We are taking something and we have reason to understand what we know and we can predict a factor of 10 or 100, but I think it is the absolute, the pinnacle of arrogance to think that what we can do, given the understanding that we have from what we've measured now and

7. 1:25:53

   predict it out a quadrillion times higher than we can see now. So my opinion, and this is partly because I'm an experimentalist, the correct way to make progress, practical progress towards the Theory of Everything, is to look around at the things that we don't have answers to right now. For instance, are there something smaller than quarks? I don't know. Is dark matter real? I don't know. If it's real, what is it? I don't know. Is dark energy real? Yes, probably, but I don't know.

8. 1:26:26

   What is the nature of space and time? I don't know. But these are questions we can explore, And I would expect, and this is my prediction, that, all right, we're going to figure things out at a factor of 10 or 100 times better than we can do now. And we might be able to do that in my kid's lifetime or something like that. But in order for us to predict a quadrillion times higher, I'm pretty sure super string theory is wrong, not because people aren't smart, but because something new is going to happen.

9. 1:26:56

   I mean, if you were talking about chemistry, you would have never predicted nuclear physics. And that's a small increase in energy, right? The idea that there's something in the nucleus of atoms that causes the sun to burn, there's a reason why people didn't believe, you know, they calculated how old the sun should be and it should only be 10 million years old because otherwise it would burn out. Well, that's clearly wrong and it's wrong because of nuclear physics.

10. 1:27:21

    That is why I feel fairly confident to say, well, someone could think, well, super string might be right or something. maybe it's right. And I hope it's right. It would be awesome if it's right. But what are the odds when you're making something with that tiny lever arm, predicting it out a quadrillion away and say, oh yeah, we got it right. What are the odds? And my answer is, you've got to be kidding me.

11. 1:27:45

    Now, I could be wrong. And I admit that I could be wrong. But that's why I think the real issue