Tim Maudlin What's at the bottom of reality?

Prof Tim Maudlin talks about his ideas of space, time and quantum theory amongst other things

[mofostopheles]

This was great a interview, touching on nearly everything that has been argued since antiquity. Bravo!

[notanemoprog]

Truly fascinating and what a fabulously optimistic view of mankind's possibilities there at the end!

[ramlosaclash]

Powerful interview, big thank you, both. Donald Hoffman is definitely working towards finding out what lies beneath/beyond our current, obviously limited, understanding of reality. He's done some very thought provoking interviews available here on YT. Maybe you could use your easy-to-listen-to and most effective interview style to coax some more out of him. Thanks again for your great shows.

[enterprisesoftwarearchitect]

Phillip, 22:00, I think the straightforward answer is, yes, wavefunction/quantum state description could just be a model that falls out of some property of whatever is “beneath”.

[KipIngram]

I'd recommend to Dr. Maudlin that he take a look at casting his discrete theory using geometric algebra rather than the standard vector calculus. It's just far more graceful, particularly in higher dimensionality. Curl in particular is an issue - it only really properly exists in three dimensional manifolds, because in such manifolds you can make a one-to-one correspondence between bivectors (the things that REALLY describe certain things) and vectors (the things we represent with curl or other cross-product related quantities). The bivector formulation extends naturally and comfortably to any number of dimensions. It's the same stuff, really, just with an adjusted mathematical representation.

[farhadfaisal]

There is at least one issue with the 'pilot wave' theory. According to this theory both the 'wave' and the particle 'trajectory' are physical entities (or, physically 'real'). But, only the wave acts on the trajectory (e.g. 'guides' it) but the trajectory does n o t act on the wave! Why is this asymmetry? This is unlike any two physical entities that, if they interact at all, they 'inter-act' on each other mutually.

[nneisler]

Plenty of people still don’t like non-locality so no need to dump on Einstein. I think we understand more why we need it but are still working on the ramifications

[enterprisesoftwarearchitect]

I admire Maudlin. Nice interview. Interviewer and Maudlin both know the basics and more of the theories and frameworks out there!

[davidwright]

There is indeed an empirical test for whether a pink elephant materializes in the refrigerator when you close the door. The overall mass of the refrigerator would suddenly increase far beyond the ability of the floor to hold it. If the refrigerator crashes down into the apartment below on closing the door, you've shown the appearance of an elephant-mass object. You might also rig a camera in the refrigerator to be triggered if an object appears in it. The camera is of course color-sensitive; so pinkness and mass may be jointly tested. QED. But no QED invoked.

[dcorgard]

A thought that's been on my mind lately:

I wonder if, in attempting to unite QM & GR, that we are pursuing an impossibility? Maybe we can't find the link because there simply isn't one - why couldn't two separate "entities" come together to make the Universe work without there being any direct connection between them? What exactly convinces Physicists that they must be connected, other than pure human want? Because both act within or upon Space-Time? That doesn't appear to be sufficient enough for me.

I've never heard this be argued by anyone before... and would really like to know what those more involved in the Philosophy side of things think of this inquiry...

Or... are we "not supposed to ask such questions"?

Edit: Typos and some slight changes.

[FigmentHF]

Hey, I’m pretty new to all this, it’s all fascinating.

One question I have is- what do we even mean when we say that something is “weird” or “spooky” or “strange”, with regards to discoveries about the fundamental processes that give rise to the universe? Strange in relation to what? How are we defining “strange” here?

We have no other universes that we can observe that are behaving in a way that’s “normal”, for us to call this one “strange”?
Is it simply that people are just feeling that its “strange”, with relation to our macro physics and classical models? That it’s counter intuitive and not entirely compatible with how we perceive reality from a first person perspective?
Because if so, that’s… oddly unscientific? We can’t reject things like non-locality and branching wave forms, simply because they don’t conform to intuitions formed by our tree climbing, apple eating ape brains, about how these things “should” be?

It feels intuitive to me that we should expect the ultimate nature of reality, to be far stranger than we can possibly imagine.

[amihartz]

Bell's proof doesn't rule out locality. It only rules out locality if you (1) believe there are hidden variables, or (2) think the wave function represents a literal entity which collapses when observed. The PBR theorem only rules out psi-epistemic models under non-relational frameworks. It doesn't address relational quantum mechanics. There's also superdeterminism it doesn't address, although that approach has its own problems.

[kyberuserid]

Was gonna watch but read the enwiki Tim Maudlin article instead. DIdn find any stinkers, e.g. countenancing religion but also didn have any interest in opinings on the shit show that is modern physics if there wasn gonna be some payback for the time which I assessed there wouldn.

[dimitrispapadimitriou]

Besides some inevitable disagreements, that was an enjoyable discussion, with good and relevant questions and answers.

[Paul]

Math is effective in physics because physicists look for regularities, which are structural, and math describes structures.

[KipIngram]

I think that in the end the "right way of looking at things" will have to at least ACKNOWLEDGE, if not describe rigorously, the notion of mind. There is an appealing parallel with quantum ideas here. Consider some internal experience you have. The sensation of red, the love you feel for your child, or whatever. This is real - we have all had these internal experiences. They are undeniable. But you can't "share" such an experience, in its totality, with anyone else. It is private to you. You also can't REALLY "store" that full experience and re-live it again later. There's just too much to it. You can try to use words to describe it to someone, or write it down in your private journal to read later yourself, but at best this is just a "surface semblance" of the experience.

I find this to be a strong analogy to a quantum state. Quantum states seem to have SOME kind of reality - if they didn't it's hard to see how quantum computing would work at all. But we can't "snapshot" them - we can't COPY them (no cloning theorem). We can extract some hard information from them, via measurement, and THAT we can write down or copy or communicate, but that's just a nuance of the full quantum state. This similarity is striking to me.

Science as a discipline revolves around objective information that we can share and discuss and, most importantly, AGREE ON. The information inherently MUST be shared (copied an arbitrary number of times) in order for us to run our collaborative scientific method. So that method is innately constrained to these "collapsed representations" of what's really going on in the world. We simply can't do science with quantum states in full. We can dance around them and say a few things about them, but we can't truly "get at them" with our methods. I think that the reality has a "mental component" that we will never be able to access in full, and that the best we can do is build science around our (collapsed) objective PERCEPTIONS of this reality.

Some particularly hard core materialists have tried to dodge this whole issue by simply DENYING the reality of these internal subjective experiences. That's just sheer madness in my eyes. Or arrogance - the desire to claim full victory in the scientific quests leads them to simply throw out the parts that we can't capture scientifically. It just doesn't feel like the right approach to me. I do think the fullness of these things is forever out of our scientific reach, but I think we can't get away with not at least acknowledging them.

What our theories are really doing is trying to predict future collapsed representations - future perceptions. These perceptions, taken in aggregate, are like a movie playing out for us on some kind of a canvas. We can make models of that canvas and models of the underlying mechanisms of the perceptions to our heart's content. Maudlin likes Bohmian-style approaches. Fine - there's nothing wrong at all with adding local beables to your model of what's happening on the canvas. If the predictions come out right, that's groovy. But we just need to remember that we are not modeling all of reality - we are modeling the aspects of it we can see, copy, and talk about. The fullness of it is just beyond us.

[KipIngram]

I eventually came to understand this, but the first times I heard Maudlin talk about "adding a foliation" I had no idea what he meant. It would probably be worth defining that when making the argument, just for people unfamiliar with the terminology. Just say out loud that a foliation is a set of slices in spacetime, stacked together, such that each slice is a "slice of simultaneity" - a "now" slice. Best I can tell that's all the term means.

Lingo is an impediment to people building their knowledge. Mathematicians are particularly bad about this - they tend to develop their specialized terminology, and then write papers using only that terminology. Many a time this has kept me from grasping papers I'm trying to read. I'm dogged about it, though, and eventually I will find a paper written to TEACH rather than just to communicate with other mathematicians already in the club, and more often than not my reaction then is "Oh, now I see. Well, that's actually simple as it can be." So, if you define your less than completely common terms, you'll reach a wider audience.

[JoyceElroy-zw]

Hernandez Elizabeth Moore Brian Rodriguez Kimberly

[JavierBonillaC]

If I was Tim I wouldn’t laugh after pointing out what other people believe. He says if you are Physicist you think that things are there only one you’re looking at them. Ha, ha, ha ha ha, ha ha what does that mean? That he thinks physicists are stupid? As Tim very well knows, the dual slit experiment makes a particle behave like a particle and not like a wave only when you’re looking or measuring. why would he laugh of that? The world does behave differently when we re not looking. He has completely confused me, because he knows that is true. So I don’t know if I u de estand.

[dadsonworldwide]

I'd say every classical American linage, every artist, most precision machinist and technicians probably gets upset when they hear someone claim that the smallest scales are not intuitive.
On the contrary we straddle this scale , 2 known standards we can be precise enough but its never perfect. Someone living in a class or a few replicating test doesn't witness our equations stressed to the limits. For sake of efficiency they to invoke hidden variables scrap it and write down some super positions musical chairs to document the answer they want. Because sending equations back to 1900s higher ed will not accept or try to fix it.lol
. Our 5 senses absolutely correlates With low energy state of a cool red apple . And once a consensus is built no magician can come along and trick into thinking purple high entropic state hot apples are really red ..
Smell, touch, taste, hearing is very active when it comes to this.

Denying it as if we all live in 3 degrees of motion on classical scale is silly.

We are now able to use inferred and enhanced cameras to share exactly what intuitiveness many all encompassing intelligent minds have always had in common .


1900s structuralism demands for recruitment of Euclidean abstract minds with good memorization skills who also tend to be more passive appropriately lacks such intuitive skill sets.