Sarah Walker
speaker
510 appearances
1 recordings
1 series
first heard Jun 2024
last heard Jun 2024
Sarah Walker’s voice in public audio — every appearance, attributed to the second.
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And I think that's not actually the way the universe really works. I think it's a good approximation for the kind of systems that physicists have studied so far. And I think it will radically fail, um, in the long term at describing reality at its more basal levels. I'm not saying there's a base.
I don't think that reality has a ground, and I don't think there's a theory of everything, but I think there are better theories, and I think there are more explanatory theories, and I think we can get to something that explains much more than the current laws of physics do.
Yeah, you know, like in physics right now, it's really popular to talk about theories of everything. So string theory is supposed to be a theory of everything because it unifies quantum mechanics and gravity. And, you know, people have their different pet theories of everything.
And the challenge with a theory of everything, I really love this quote from David Krakauer, which is a theory of everything is a theory of everything except those things that theorize.
Yeah, but it's also weird because if a theory of everything explained everything, it should also explain the theory. So the theory has to be recursive. And none of our theories of physics are recursive. So it's a weird concept.
I don't think so. I think you can build a theory acknowledging that you're an observer inside the universe.
I think so. I mean, I don't think, there's always going to be the paradox of another meta level you could build on the meta level, right? So like if you assume this is your universe and you're the observer outside of it, you have some meta description of that universe, but then you need a meta description of you describing that universe, right? So, you know, this is one of,
The biggest challenges that we face being observers inside our universe and also, you know, why the paradoxes and the foundations of mathematics and any place that we try to have observers in the system or a system describing itself show up. But I think it is possible to build a physics system.
that builds in those things intrinsically without having them be paradoxical or have holes in the descriptions. And so one place I think about this quite a lot, which I think can give you sort of a more concrete example, is the nature of what we call fundamental. So we typically define fundamental right now in terms of the smallest indivisible units of matter.
So again, you have to have a definition of what you think material is and matter is. But right now, what's fundamental are elementary particles. And we think they're fundamental because we can't break them apart further.
And obviously we have theories like string theory that if they're right, would replace the current description of what's the most fundamental thing in our universe by replacing it with something smaller. But we can't get to those theories because we're technologically limited.
And so if you look at this from a historical perspective and you think about explanations changing as physical systems like us learn more about the reality in which they live, we once considered atoms to be the most fundamental thing. And, you know, it literally comes from the word indivisible.
And then we realized atoms had substructure because we built better technology, which allowed us to quote unquote, see the world better and resolve smaller features of it. And then we built even better technology, which allowed us to see even smaller structure and get down to the standard model. particles.
And we think that there might be structure below that, but we can't get there yet with our technology. So what's fundamental, the way we talk about it in current physics is not actually fundamental. It's the boundaries of what we can observe in our universe, what we can see with our technology. And so if you want to build a theory that's about us and about what
What's inside the universe that we can observe, not what's at the boundary of it. You need to talk about objects that are in the universe that you can actually break apart to smaller things. So I think the things that are fundamental are actually the constructed objects.
They're the ones that really exist and you really understand their properties because you know how the universe constructed them because you can actually take them apart. You can understand the intrinsic laws that built them. But the things at the boundary are just at the boundary. They're evolving with us, and we'll learn more about that structure as we go along.
But really, if we want to talk about what's fundamental inside our universe, we have to talk about all these things that are traditionally considered emergent, but really just structures in time that have causal histories that constructed them and are really actually what our universe is about.
I don't see one.
I think so, yeah. I think for me, the frontier in modern physics, where the new physics lies is not in high energy particle physics. It's not in quantum gravity. It's not in any of these sort of traditionally sold, this is going to be the newest, deepest insight we have into the nature of reality. It is going to be in studying the problems of life.
and intelligence and the things that are sort of also our current existential crises as a civilization or a culture that's going through an existential trauma of inventing technologies that we don't understand right now.
Showing 101–120 of 510 · page 6 of 26
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