Mindscape 75 | Max Tegmark on Reality, Simulation, and the Multiverse

We’ve talked a lot recently about the Many Worlds of quantum mechanics. That’s one kind of multiverse that physicists often contemplate. There is also the cosmological multiverse, which we talked about with Brian Greene. Today’s guest, Max Tegmark, has thought a great deal about both of those ideas, as well as a more ambitious and speculative one: the Mathematical Multiverse, in which we imagine that every mathematical structure is real, and the universe we perceive is just one such mathematical structure. And there’s yet another possibility, that what we experience as “reality” is just a simulation inside computers operated by some advanced civilization. Max has thought about all of these possibilities at a deep level, as his research has ranged from physical cosmology to foundations of quantum mechanics and now to applied artificial intelligence. Strap in and be ready for a wild ride.

Max Tegmark received his Ph.D. in physics from the University of California, Berkeley. He is currently professor of physics at the Massachusetts Institute of Technology. He has played an important role analyzing data from large-scale structure and the cosmic microwave background. He is the author of Our Mathematical Universe and Life 2.0: Being Human in the Age of Artificial Intelligence. He is a co-founder of the Foundational Questions Institute and the Future of Life Institute.

[TheOriginalRaster]

Best guest of the series. Fantastic podcast. I found it very easy to follow Max's ideas. He did a great job of explaining ideas.
Cheers!

[larmufc]

Sean can you get a studio, I want to see you guys talking.

[AhmadN]

Wowww. Two of my most favorite people discussing big questions. Enjoyed it so much. Thank you Sean, thank you Max.

[philipgebhardt]

Love Max Tegmark- first saw him on some of the BBC Horizon programs on Cosmology and the Multiverse

[hamentaschen]

Sean Carroll AND Max Tegmark!! I'm hitting the 'like' right now before I even begin. No way this ain't turning out awesome!

[rumidude]

Max is ALWAYS thought provoking. I am glad he shares himself with the world as he does.
Thanks for having Max on and turning him loose on the rest of us.

[NerdOutWithMe]

Really enjoying your podcasts, Sean. Great to listen to at work!

[bitegoatie]

The numbers are just as invented as the names, regarding the moose discussion. We do best in science when we stay close to the stuff we want to explain - fads of the day, like simulations, pixilation, our latest geometry, mathematical realism (which has gone through many waxes and wanings), anthropical inference, and all manner of others, rarely stand extended scrutiny as theories of physics or philosophy. We care about physics so far as it explains elements of the world we live in. We live and die in the physical world. Beyond complete skepticism about the physical world (from which there is no extracting oneself), the idea that mathematics exists and that Occam’s razor can shave off reality can very much have the tables turned on it. We very easily distinguish among abstractions and physical things in the actual world and the idea that math explains regularities in our perceptions very well goes to why we invented mathematical discourse. What mathematical discourse does less well at capturing happens to be very well captured by other languages - the value of which and the head-breaking reality of which theories like mathematical reductionism has to explain away in a manner that would require enormous metaphysical commitments to make it stick.

[ameremortal]

Max and Sean both put the equations before any assumptions in their thinking process. This makes them a very powerful team. I hope you guys share more of your mutual talks with us.

[DanielKarbach]

Ah, this universe with Sean Carroll, it's preposterous!

[algroc]

"Hope comes from imperfect information." Very nice

[mbaske]

Prefers to be in a superposition of drinking beer while watching netflix.

[TheSpinelessNinja]

8:38 "...a universe where you're interviewing Max Smegmark"

Please no

[cashkaval]

I'm sorry Sean but there's one problem with this episode. It was too short

[fantasiaenre]

The basis of logic & logical thought is sequential. When we map reality to this sequential structure we reduce it to that structure,
or as it is said, "simplify" it to this structure. The nature of reality is not sequential, and as far as we are aware, all of reality (in all its infinity)
"happens", "exists" all at once, spontaneously in all its "parts". Forgetting this is at the root of many of the confusions mentioned in this podcast, and by extension, anything that is modeled or is "fruit of" this structure of thinking. "Mathematics" is of course an instance of
this structured thinking; or we can go further, an instance of 'algorithmic thought.'
Under this realisation, the question of "is the world Math?" is transparently non-sensical or non-productive.



More interesting is understanding what are the realisations to be made under the "mathematical models of the world", known as 'physics',
especially when it concerns to its "paradoxes", for example in quantum mechanics and the "limits" of its precision, or even the
"true" meaning of ".. 'energy/matter' is neither created nor destroyed" in the context of our myopic search for the 'indivisible' parts of 'the universe'. In the end we are experts in getting lost in our own symbols, even in the symbols of "our Self"s.

[Bisquick]

I feel like semantics are getting in the way of a lot of these concepts. Specifically, the simulation argument and it's comparability to what Max was saying at the beginning; that there is no "property" of physicality. I presumed these things to be essentially the same, but it seems like he's making some distinction that may or may not just come from the word "simulation" itself. If that makes any sense. I'm basically thinking holographic principle extrapolated all the way down and all the way up, kind of arriving at a similar hypothesis to Penrose's conformal universe thing. Or something. To be clear, I have no idea what I'm talking about.

[nateostrowskimusic]

Love when these get just as philosophical as they do scientific. Perfect podcast!

[FABRIZIOZPH]

I'm sorry Max... But your theory that everything is Made of mathematical relationships doesn't sound right.. To say that the regularities of the universe can be described by mathematic is not equivalent to saying they are made of it..

[madderhat]

Max Tegmark sounds like a 50's cinema 'action' scientist.

[hmdshokri]

even though Mad Max is a really crazy scientist, at least he is not shying away from big questions.