korrents

korrents · Lex Fridman Podcast · #403

Lisa Randall: Dark Matter, Theoretical Physics, and Extinction Events | Lex Fridman Podcast #403

Lisa Randall · 59m · youtube.com

16 korrents from this recording

Lisa Randall did not write this page.

Every claim below is a statement made in this recording, quoted word for word and linked to the second it was said, so you can hear it rather than take our word for it. The wording comes from the transcript published alongside the recording; the sentence above each quote is our reading of the claim, not their wording.

  1. 3:06 · watch on youtube.com

    In fact, dark matter is in some sense more important because it can collapse more readily than ordinary matter because ordinary matter has radiative forces, which makes it hard to collapse on small scales. Actually it’s dark matter that drives galaxy formation and then ordinary matter comes along with it.
  2. 2 min later
  3. 5:03 · watch on youtube.com

    In fact, I would say it’s more surprising that the matter that we know about is constitutes as big a fraction of the universe as it does. We’re limited, we’re human. The fact that we see 5% of the energy density of the universe, about one sixth of the energy density in matter, that’s remarkable.
  4. 3 min later
  5. 7:35 · watch on youtube.com

    The interesting thing is that if some of the dark matter does radiate, and I like to call it dark light because it’s light that we don’t see, but dark matter would see. It could radiate that and then it could perhaps collapse into a disk the same way ordinary matter collapsed into the Milky Way disk.
  6. 2 min later
  7. 9:27 · watch on youtube.com

    That’s also why I like the dark disk because there’s a scientific story behind it. As far-fetched as it might sound, you could actually go and look for the experimental consequences, for the observational consequences to test whether it’s true.
  8. 5 min later
  9. 14:11 · watch on youtube.com

    That was originally one of the hopes of Large Hadron Collider. I’d say at this point, it would be very unlikely given what they’ve already accomplished, but there are these underground detectors, xenon detectors that look for dark matter coming in, and they are going to try to achieve a much stronger bound than exists today.
  10. 2 min later
  11. 15:51 · watch on youtube.com

    It’s one of the many factors I think that went into the fact that the Large Hadron Collider became the only machine in town, and the Superconducting Supercollider would’ve just been a much… If it had really had achieved what it was supposed to, would’ve been a much more robust test of the space.
  12. 16:07 · watch on youtube.com

    I’d say for humanity, it’s both a tribute to the ability of discovery and the ability of really believing in things so that you have the confidence to go look for them, but it’s also a cautionary tale that you don’t want to assume things before they’ve been actually found.
  13. 3 min later
  14. 19:29 · watch on youtube.com

    I do think that we might be in the middle of an extinction right now if you define it by the number of species that are getting killed off. It’s subtle, but it’s a complex system.
  15. 3 min later
  16. 22:51 · watch on youtube.com

    I think they’re not as scared as they should be about nuclear weapons, to be honest. I think that’s more serious danger than people realize.
  17. 9 min later
  18. 32:20 · watch on youtube.com

    One of the things we do as physicists is we actually want it to break down at some level, we’re looking for the precision measurement or the energy or whatever it will take where the standard model is no longer working. Not that it’s not working approximately, but we’re looking for the deviations.
  19. 5 min later
  20. 36:58 · watch on youtube.com

    I could believe that the Middle East doesn’t exist because I’m not there now. That would be kind of ridiculous, I think we would all agree on that. I think there’s only so much that we can attribute to our own powers of seeing. The whole system doesn’t come into being because I’m measuring it.
  21. 1 min later
  22. 38:01 · watch on youtube.com

    I might not seem so, but I think I’m more humble than a lot of physicists. I’m not sure that we’re ever going to get to that bottom level, but I do think we’re going to keep penetrating different layers and get further.
  23. 7 min later
  24. 45:16 · watch on youtube.com

    After that, he thought top-down was the way to go, but he actually didn’t make that much progress. I think it’s naive to think it was just one or the other. In fact, a lot of people who made real progress were rooted in actual measurements.
  25. 2 min later
  26. 46:54 · watch on youtube.com

    I do think that string theorists were a bit overly ambitious… Not overly ambitious, but a little bit overly arrogant in the beginning, thinking they could solve many problems that they weren’t going to solve.
  27. 3 min later
  28. 49:54 · watch on youtube.com

    Large language models are more or less generalizations of stuff that we have. There’s still breakthroughs in AI waiting to happen, and maybe they are happening and maybe they’ll be good, maybe not, but that’s not quite the same.
  29. 5 min later
  30. 55:10 · watch on youtube.com

    I think the weird thing about being a scientist or an academic in general is you have to believe really strongly what you do while questioning it all the time. That’s a hard balance to have.