Olaf Dreyer: This One Number Explains the Beginning

SPEAKER_1 (0:00)

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Olaf Dreyer (0:30)

It was the weirdest thing. This cannot possibly be a coincidence. There's something missing. This number, this 0.04, is the thing that we see in the sky. And when I saw this, I was like, what?

Curt Jaimungal (0:42)

This is physicist Olaf Dreyer, who earned his PhD at Penn State and helped develop black hole spectroscopy. That is, testing Einstein's theory through the ringing of black holes. His top two papers are some of the most talked about in the field of black hole spectroscopy, and loop quantum gravity.

When I asked him about how he views the field of high-energy physics, he said, I want the new stuff.

Olaf Dreyer (1:03)

Don't be arrogant about tools. You can't kill things too early. Just sort of be open.

Curt Jaimungal (1:09)

On this channel, I, Curt Jaimungal, interview researchers regarding their theories of reality with rigor and technical depth.

Olaf Dreyer (1:15)

I want to understand nature, not to abstract math.

Curt Jaimungal (1:20)

Today, I'm thrilled to bring you Olaf Dreyer on how spacetime and matter emerge together. And even toward the end, we talk about the puzzle of consciousness. How could we ever know?

Olaf Dreyer (1:31)

I mean, I don't know that you're conscious.

Curt Jaimungal (1:34)

There's a slide that's been burned in your memory.

Olaf Dreyer (1:36)

Yes.

It's been very important for me. So maybe like a short backstory. Right. So I'm from Hamburg, and in Hamburg, there was this group of theoretical physicists, and they called themselves algebraic quantum field theorists. And it was an attempt to make quantum field theory rigorous, which appealed to me. Somehow I'm like this mathematical kind of guy.

So I became a student in that group. And it was in some ways, it was great. I mean, Buchholz was maybe the best advisor I've ever had. He's like, Buchholz is the professor working on that algebraic quantum field theory. But that field, I think it's fair to say, never produced any result that is of note. But you have three generation of people working in that field, and they produce nothing you need to know.

Curt Jaimungal (2:41)

In algebraic QFT?

Olaf Dreyer (2:43)

In algebraic quantum field theory.

Curt Jaimungal (2:45)

And that's different than axiomatic QFT?

Olaf Dreyer (2:48)

It's a bit different because in the fundamental object in algebraic quantum field theory is an algebra, just an abstract algebra, and all the physics supposedly is in the mapping of space-time regions to algebras.

That means very abstract and almost says nothing, right? In algebraic, sorry, in quantum field theory, in axiomatic quantum field theory, you are a bit closer to the standard quantum field theory in that the fundamental objects are actual fields, or they're actual fields.

Curt Jaimungal (3:26)

What about the recent work with Witten and Pennington with type 3 algebras like of the past five years or so?

Olaf Dreyer (3:33)

That I'm not familiar with. I'm sure this is very different from what Haag did then.

Curt Jaimungal (3:40)

I see.

Olaf Dreyer (3:40)

It's a completely-

I mean, it's a very different thing. There's almost no-

I mean, they're their own group, like completely separated from the rest of theoretical physics. Okay. So I was there, student. I loved it. There was this thing of sitting with Buchholz in his office on the blackboard and figuring stuff out. It's like the best advisor experience I've ever had. But as I said, I think that they didn't produce anything. I didn't go into physics to not produce anything. I want to understand nature, not to abstract math. That's different things.

And so I was getting kind of like nervous. Like, okay, what am I doing here? What is this? And then Abhay came to Hamburg. Abhay Ashtekar. Abhay Ashtekar. I didn't really know about, sort of like very remotely knew about him. And I think he was visiting Nikolai, Herman Nikolai. Does that, do you know him? No. He was, at that stage, was the professor at DAISY, at the Institute for Theoretical Physics. And then later became the director, director of the Max Planck Institute in Berlin, which is like a super important position. And he played a role sort of in the time of String Theory when it was like super hyped. And they had one of the big String Theory conferences in Berlin. Okay. So he invites Abhay. He gives a talk. And I don't remember anything of the talk except this one slide. And this one slide was like a sort of a road map to the Abhay Ashtekar quantum gravity program. And so he said like, okay, first we're going to do this and then we do that. And then this is the way to like success. And if this doesn't work out, then there was this one corner, which I remember, which was almost like a waterfall. Okay. So if we end up here, then everything falls apart and it won't work.