Episode 36: David Albert on Quantum Measurement and the Problems with Many-Worlds

Quantum mechanics is our best theory of how reality works at a fundamental level, yet physicists still can’t agree on what the theory actually says. At the heart of the puzzle is the “measurement problem”: what actually happens when we observe a quantum system, and why do we apparently need separate rules when it happens? David Albert is one of the leading figures in the foundations of quantum mechanics today, and we discuss the measurement problem and why it’s so puzzling. Then we dive into the Many-Worlds version of quantum mechanics, which is my favorite (as I explain in my forthcoming book Something Deeply Hidden). It is not David’s favorite, so he presents the case as to why you should be skeptical of Many-Worlds. (The philosophically respectable case, that is, not a vague unease at all those other universes.)

David Albert received his Ph.D. in physics from Rockefeller University. He is currently the Frederick E. Woodbridge Professor of Philosophy at Columbia University. His research involves a number of topics within the foundations of physics, including the arrow of time (coining the phrase “Past Hypothesis” for the low-entropy state of the early universe) and quantum mechanics. He is the author of a number of books, including Time and Chance, Quantum Mechanics and Experience, and After Physics.

[brettonwoodsvsbtc]

Sorry I struggle with Albert he talks in riddles and around points never getting to an answer or cementing his view

[serpahologramsson]

Didnt know who you were Sean, until i saw you on Joe Rogans, now im hooked on your podcast, your such a good guy, scientist and podcaster

[goodmmann]

He waffles and waffles with very little substance

[ljttlebro]

Forget the wave function. My brain has collapsed.

[chasekanipe]

David Albert is my favorite guest thus far. Definitely have him on again.

[wcropp]

I love listening to David Albert and anything to do with the foundations of physics. The extra length was fine by me. Definitely bring him back some time and finish the discussion!

[superdog]

I don't understand Albert's explanation at 1:11:00

[lucasthompson]

Guest/Show request:
"Nima Arkani-Hamed on Spacetime, SUSY, and building larger colliders"

Also, I think this would be fun:
"Leonard Susskind on Black Holes and no, I am not Mike from Breaking Bad" 😆

[zero]

"Sadly, we didn't get quite enough time to talk about what approaches to QM that he IS in favor of..." - Sean Carroll on a podcast that's 18 minutes shy of 2 hours.


Alright, let's do this.

[SuperGnarley]

Please get *David Deutsch* on the podcast!!!

[lonelycubicle]

Sean, this was a little over my head (ok, a lot) but since you & David are smart guys, making good faith efforts to get at the truth, it would be interesting to hear your 5 minute summary of where exactly you & David differ on many worlds, what fact would bring you to David’s side & vice versa, if that’s possible.

[Mentat]

Has Tim Maudlin never been a guest? I feel like he'd have some really great contributions to make on both quantum mechanics and relativity (especially shedding light on some remarkable things Bell said on both matters).

[GnomiMoody]

Loved the length of this one. Longer is better.

[jonathanhenderson]

Basically, all I got out of this ~2hr video beyond the history of QM interpretations is that Albert doesn't like the fact that MW basically makes probability meaningless in a sense. I can't help but wonder: so what? I don't even think he's right about that, though it might require a redefinition of what probability actually is. If every outcome happens, then we're not asking about the probability of it happening, but about how many versions of us will see any given outcome. It basically reduces probability to statistics in a sense.

[cauchy]

Smart people who disagree are excellent guests to have conversations with! Thanks for the great podcast Sean.

[mrloop]

In another world this comment is replaced by a concise, obviously true interpretation of quantum mechanics.

[semidemiurge]

Listening to David Albert is a challenge. His answer/point is only reached after a long random walk of excursions into tangentially related minutea.

[SavageScroll]

It always puzzles me that there are time limits imposed on such conversations. How dare you, Sean?

[ddavidjeremy]

My favorite podcast ever. I wish I were smart enough to posit a theory that David could then destroy using his philosophical contrarian sledgehammer of logic. A man can dream can't he.(and he can't, and can be both doing an not doing the dreaming till measured)

[SaintJohnVideo]

Superb episode, as usual! I'm sure you have plenty of ideas for folks to co-host in future episodes, and I'd like to inspire you to maybe have someone that is pushing more "fringe" theories, like Erik Verlinde. I think you've already been through a MOND phase of your research and a conversation with both of you might be able to explain to us the gaps between MOND theories and observations. I'd also love to hear Edward Witten and Juan Maldacena. Thank you for helping to teach and inspire us!