As someone new to the foundations pod space, I really liked this pod for 2 reasons. 1) I've never heard of causal set theory and would like to learn more and 2) I loved seeing Faye be able to discuss the consciousness ideas freely in a safe, supportive space where it's okay to explore new ideas - peer review free. Bravo!
Incredible interview; another gem! It’s pretty wild that I’ve been through all the presentations by Fay that I can find on TH-cam, but I feel like this interview gave me a better sense about how Fay views/understands causal set theory than any of the other interviews/presentations.
Thought provoking interview. Space is real in yet another way. What can't empty space do! In so many ways this universe continues to prove that it's a factory structured to make empty space.
Awesome conception of conscious experience as the objective process (via discrete quantum like description of space Time, honoring Lorentz invariance via volume instead of plank Length, causal order etc) of birth of spacetime atoms in the brain in causal set theory, which is by implication an internal view because of the relativistic structure. Completely novel and intriguing concept to me. Robinson and impcat 🐈 (aka Pins), this is real education you are providing). Thanks so much!
I thought of this idea when watching this video, it's an abstraction of a timing array. The idea is there's some finite number of poles, and each one of these poles produces timing pulses in response to absorbing energy. Using these timing pulses as asynchronous data streams, the information is integrated to create a map of reality of complexity proportional to the number of poles used as sensors. The thing about this timing array device, is it's really useful for orienting yourself. My hypothesis is that EVERY sensory device is some variation of this form. That's pulsar timing arrays, photoelectronics, optical nerves, and EVEN FUNDAMENTAL PARTICLES must have this internal structure in order to interact with spacetime. A particle with poles in two orthogonalities will only have structure in those two orthogonalities. It's not just sensory when it's on the level of particles, it also explains the projected spacetime they inhabit. So, that's a kind of automaton definition of spacetime, whereby spacetime is defined in terms of the device that senses it. Something like a cross between Turing and Platonic solids. Note: causal set theory is the solution to the ordering problem of asynchronous timing pulses. Also, there's uncertainty principles all over the place in this one, as it maps a probability space, and there's an underlying ordering problem that's being illuminated by the device. Not all the ordering problems are solvable, nor should they be.
I'm convinced causal sets represent actual paths in eucledean space(of some superdeterministic theory). Wavelengths could possibly shift as in VSL theories.
You should have Juliet Floyd of BU on your podcast. Leading scholar of Wittgenstein and an amazing speaker. Big fan of your podcast, and it would be amazing to see her answer your spot-on questions.
Oh My Gosh.... I like your t-shirt and the pod-cat a lot...! You both remind me of a couple of my professors from uni (I've attended a few) and wow, I love it. Thank you for sharing. I think you would get along quite nicely. A couple of maths professors (Arvid Siqveland, Johannes Kleppe) or my professor in aluminum welding etc Medhi G. Mousavi.
@49:00 this is where many people go astray (which, don't get me wrong, is a _good_ thing, because cutting edge science needs explorers). Quantum theory is a framework for analysis, it is not ontology (at least not _necessarily_ ). It employs measurement propositions. But the thing is, those are a way of talking about otherwise pretty classical systems in the background. In QM you "give up" on knowing the classical variables precisely. But you are never compelled to say they are not real. You instead are compelled to say we cannot measure certain sets of them simultaneously, plus, they exhibit entanglement. But since ER=EPR offers a GR way to "explain" entanglement, you begin to see QM is just a subtle form of classical mechanics, with clumpy spacetime topology. What about superpositions on top of entanglement? Well, I am not sure they are different phenomena, but if there is non-trivial topology at some scale, then below that scale there will be closed timelike curves, so on that scale there will be effective superpositions. These are not SOH. SOH is more statistical --- accounting for the potential of all paths. Whereas the topological geon ER=EPR picture is that any paths may occur, but we cannot know which from past light cone data. Hence we are forced to use some non-Kolmogorov statistics. If anyone wants to help me develop such ideas, it can be a lot of fun, contact me here: See t4gu.gitlab.io/t4gu/philosophy/ for some serious related fun musings. I just do this as a hobby these days.
@1:33:00 Fay's "birth of spacetime atoms" idea for linking to the hard problem of consciousness is reminiscent of George Ellis' Crystallizing Block Universe (CBU). He'd also be a good guest. Not that I endorse those ideas. None of them have anything whatsoever to do with subjective mental qualia (the actual Hard Problem qua Chalmers). To be clear, saying consciousness is a process is a cop out of William James proportions (people have made that cop-out since forever). A process has no subjective mental qualia. You have to explain the subjective qualia. To my knowledge no one ever has. Not with any science or math concepts. The only folks I know who remotely come close are poetic, that's merely because poetry and metaphor are imprecise, hence can at least have some pretense of completeness (as in, "Sure mate, there is a God, but I have no friggin' idea what It is."). Science seeks precision but not completeness. When will scientists realize Gödel essentially said no science based on precision (hence mathematical) can ever be complete? That's not to say consciousness cannot come under the remit of scientific precision some day, but it is a good reason to guess it might not. Which is only to say, less hubris please, when scientists try to explain consciousness.
We force space-time as a block into the small, and the universe complains by spitting out probabilities, because at that scale there is no space-time yet, it emerges, so the answer is: these are the possibilities that can be realized.
The duality of matter and the emergence of matter overlooks the substrate upon which matter exists, space. Materialist perspective is a philosophic substrate with little to assist your understanding.
Can you get Xiao Gang Wen perhaps and Subir Sahdev to the podcast, could be a great convos. Xiao is Ed Witten student, working on topological order and spin liquids
Quantum non-locality: would that mean that the extreme fluctuations at the Planck level is an indication of dimensional boundary say our Space/Time curled within a higher dimensioned membrane?
It looks to me that the strength of the path integral formulation is in its close relationship to experimentation. The way spacetime is inferred experimentally between A and B is by passing a particle from A to B. If there's no way to get from A to B, we conclude that B must not be part of the same spacetime. Because of the uncertainties involved, repeated experiments between A and B are required to build up a picture of the nature of the spacetime between them. Also, another strength of this approach is that it's relational. It's stated in terms of relationships between A and B. So, a purely relational, relativistic spacetime, may take the same form. In a discrete, atomic spacetime, I wonder if it shouldn't be composed of these A-B relationships, instead of points. I think this is the reason why path integral formulations turn out to be so useful, it's because it's a good stand in for the notion of spacetime. Instead of an infinitely divisible vacuum, path integral formulations build spacetime up from probabilities. Either theoretically, or experimentally. Shouldn't there be some graph theoretical equivalent to causal set theory, in the same manner that the Church/Turing theses are related? I think causal set theory is entirely valid, but it may be treating the logic too broadly. A more physical system that can accomplish the same feat can be achieved with graph theory and some simple rules of evolution, I think.
There is also a way to refute SOH empirically, the Three Slit experiments (or N-slits for N>2). It'd be weak refutation, since those experiments are extremely subtle and rely upon near-field detectors, which introduce all sorts of possible spurious instrumental systematic and unknown errors. Standard orthodox non-SOH QM says a photon state can only be entangled with two slits, not three. But the sum of pairwise three-slit interference is extremely hard to empirically distinguish from extra interference terms from genuine three-path "exotic" loops.
@@Achrononmaster I don't know about that, it seems that there's a lot of different ways to approach a SOH problem that could produce spacetimes with all kinds of properties. I'm trying to assemble a spacetime from component parts, and the kinds of paths I'd need for this formulation wouldn't be the kinds Feynman used, they'd be one dimensional, but would produce spacetimes of whatever number of required dimensions when combined. So, this would be an explanation of where x, y and z come from. The "paths" would really be in terms of timing differences, as in a pulsar timing array. So, spacetime as a quantum timing array. Maybe it's too hard to get results from theoretically, but it definitely can be treated like this experimentally. As for entanglement, ideally if you got the logic right, the right kind of entanglement would fall out of the equations. It's not adding together paths, it's adding together possible paths, so it should produce those kinds of effects. On the other hand, I'm not against ER=EPR type explanations for entanglement, though I'm also interested in possibly modeling entanglement as a superluminal inflaton field. That would be handy in explaining inflation, dark energy and gravity.
also, try defining time as, Movement of the wave function, rather than change and you wont run into the parity issue! this new definition can be turned into an operator which can describe both Newtonian and Einsteinian "time" as, if you were to freeze the system state, what would be frozen? more fundamental than change? all wave functions are frozen, this is Newtonian "time" (absolute) the system state is frozen in "time" no perturbations everything is frozen. this is the state of existence, Newtonian "time", then let the wave functions perturbate, you have the microstates perturbating outwards in 3 dimensions, this is Einsteinian "time" (local). movement of the wave function resolves both of these into their separate domains and says time is movement of THAT wave function! the universal one of the sub wave functions. and all perturbate according to the local environment except the universal one, which perturbates at the speed of the universe.
@1:00:00 I think, all due respect, this is a fundamental misconception. Discrete structure has been around for thousands of years, the Greeks had that idea, then there was Newton, then Dalton, and many more in-between. But it is not spacetime that has to be discrete, it is the topology, at least for a first guess, which we need to consider as discrete. That is what String theory does. We do not need to set-up a discrete spacetime manifold for this. Ever heard of a pretzel? it's a smooth continuum structure. So black hole entropy is not a clue about spacetime discreteness. It is a confirmation matter is discrete. But matter is not spacetime itself per se. Consider the Clifford algebras: they employ continuum spacetime, yet contain the discrete structure in the form of the irreducible representations of the symmetries. Why do such irreps. seem to exist in nature? No one really knows, but it has to be either fields "living on" spacetime, or the topology of spacetime itself (so a version of string theory or similar). None of which require discrete space, and yet which account for BH entropy (for minimal models at least).
When I say "fundamental misconception", I mean logically. It could of course be true that spacetime is a discrete structure. But black hole entropy is no proof or hint for this conjecture.
This a very hard topic to do a podcast in question-answer form. You did a commendable job. Since the work is about establishing the concepts, asking questions in a topic where concepts are not well established is extremely difficult.
@35:00 you ask her a great question. The thing is, in classical GR we can have discrete structure, namely the ER=EPR type proposal you alluded to before which Fay rudely dismissed ("highly skeptical" - why?? prejudice and pettheoryitis? She is dissing Susskind for heavens sake!). There are dozens of theoreticians now who use Clifford algebra to get the Standard Model symmetry structures. Those are discrete structures, but fully compatible with GR, provided spacetime topology is not trivial. Why should it be trivial topology though? There is no good reason for that presumption except to avoid closed timelike curves. But clearly it is at Planck scale structure where topology is non-trivial. So that is a terrific conjecture to explore - why is non-trivial topological structure (hence CTCs) restricted apparently (empirically so) to around the Planck scale? You have to at least ask before dismissing the idea. But once you open that door, then discrete structure (homology) is possible with the spacetime continuum assumption (smoothness, not finiteness nor Finitism). This entirely, I think entirely, eliminates any need for a finiteness physical assumption. Newton beats Zeno. At least by any parsimony arguments. I mean to say... c'mon!! Finitism is a mental disease coming from _legitimacy_ from computer science culture. But physics is not computer science. So, imho, Finitism is not good science. You can adopt Finitism once Nature reveals herself to be finite. But quantum mechanics reveals no such thing, yet. (I appreciate I am in a minority here. But all the more reason I need to protest. I do not think I am _obviously_ wrong.)
Finitism is a relatively recent phenomenon, and it did arrive at around the same time as computer science thinking. However, I don't think this idea is so much from computer science as it is from observation. It is a universe with a minimum, Planck scale, and an apparent maximum, cosmic microwave background scale. These scales were established relatively recently in the scientific past, and the implications are still being absorbed. It's an apparently finite universe that won't live forever. I've had some computer science training myself, and I can give you my perspective on it. Computer science is probably misnamed, and the field has some problems. A good computer scientist will recognize that what they've been studying isn't science, it's a form of mathematics. Then once they've realized they're not scientists, they're mathematicians, the good ones will also realize that most of their classmates aren't serious mathematical researchers, they're future IT trolls in your local dysfunctional bureaucracies. The math the good ones study, though, is a very important branch of pure math. They'll learn all about Russell and Goedel. The study of algorithms is ancient, and has applications well beyond programming a computer. You can program your business into an assembly line, for example, or you can program entire societies! (That sounds sinister...) Which is to say, there's some real insight from a certain section of computer science about the nature of language and mathematics. Considering how much language and mathematics contribute to the scientific enterprise, I think it's worth enlisting this perspective when it's the applicable one. Otherwise, you're mostly right about them. If I had my way, I'd split the field into computer math (but a fancier name), and computer programming. Move computer programming into the arts department, and it can take some funding with it. That's probably where that (programming) belongs if it's to be taught at University.
Causality poses a problem in the context of entanglement, and in quantum mechanics in general, where true randomness is of the essence. For This reason, causal set is not a quantum gravity theory. It is purely classical.
A new thing I think I've learned from this interview is that this particular Hawking student doesn't like Lenny Susskind. She explained the "ER = EPR" paper and idea without mentioning its author
The ER=EPR is still a controversial idea. Not everyone finds it convincing. The same with the idea that conjectures some correspondence between quantum complexity with the growth of the interior volume/ length of wormholes/ black holes. Interesting ideas, but still are hypothetical.
@@dimitrispapadimitriou5622 Sssshhhhh! fffs. Don't tell anyone ER=EPR is good stuff... or _not_ good stuff. Some of us want to fantacize we have a virtual pinky finger on a Nobel Prize.
Dude, you're lucky that me and people like me still watch your podcast. I lost respect for you severely after watching you talk s*** about Graham Hancock and Randall Carlson. They are not pseudoscientists lol and they are not anything to be made. Fun of. You seriously discredited yourself to a lot of people on that episode
Haven't seen any new Fay content in ages, kudos for getting her on she's always incredibly interesting 👍
Yes!
A
As someone new to the foundations pod space, I really liked this pod for 2 reasons. 1) I've never heard of causal set theory and would like to learn more and 2) I loved seeing Faye be able to discuss the consciousness ideas freely in a safe, supportive space where it's okay to explore new ideas - peer review free. Bravo!
haha thanks!!
Well done to Fay, also even she has so much experience on this field, she is very humble.
Incredible interview; another gem! It’s pretty wild that I’ve been through all the presentations by Fay that I can find on TH-cam, but I feel like this interview gave me a better sense about how Fay views/understands causal set theory than any of the other interviews/presentations.
Awesome!!!
That finishing part about the past being possibly closely casually connected to the present was kind of mind blowing.
I really enjoyed her perspective. It lines up a lot with SRP's ideas of the future influencing the past. Will have to dive deeper into her work.
You should have Leonard Susskind on to give his ER=EPR spiel, it's incredibly interesting and compelling.
Thought provoking interview. Space is real in yet another way. What can't empty space do! In so many ways this universe continues to prove that it's a factory structured to make empty space.
another fire pod 🔥
Thanks!
Awesome conception of conscious experience as the objective process (via discrete quantum like description of space Time, honoring Lorentz invariance via volume instead of plank Length, causal order etc) of birth of spacetime atoms in the brain in causal set theory, which is by implication an internal view because of the relativistic structure. Completely novel and intriguing concept to me. Robinson and impcat 🐈 (aka Pins), this is real education you are providing). Thanks so much!
so glad I revisited this. Not that I won't have to revisit it again. Present is the process.
At the quantum level, physics is very spooky. Good interview.
Looking forward to this one
GOod.
I thought of this idea when watching this video, it's an abstraction of a timing array.
The idea is there's some finite number of poles, and each one of these poles produces timing pulses in response to absorbing energy.
Using these timing pulses as asynchronous data streams, the information is integrated to create a map of reality of complexity proportional to the number of poles used as sensors.
The thing about this timing array device, is it's really useful for orienting yourself. My hypothesis is that EVERY sensory device is some variation of this form. That's pulsar timing arrays, photoelectronics, optical nerves, and EVEN FUNDAMENTAL PARTICLES must have this internal structure in order to interact with spacetime. A particle with poles in two orthogonalities will only have structure in those two orthogonalities. It's not just sensory when it's on the level of particles, it also explains the projected spacetime they inhabit.
So, that's a kind of automaton definition of spacetime, whereby spacetime is defined in terms of the device that senses it. Something like a cross between Turing and Platonic solids.
Note: causal set theory is the solution to the ordering problem of asynchronous timing pulses.
Also, there's uncertainty principles all over the place in this one, as it maps a probability space, and there's an underlying ordering problem that's being illuminated by the device. Not all the ordering problems are solvable, nor should they be.
I'm convinced causal sets represent actual paths in eucledean space(of some superdeterministic theory). Wavelengths could possibly shift as in VSL theories.
Amazing!!
Thanks!
@@robinsonerhardt
Thank you!!!🙏❤️🌏🕊🎶🎵
Great, nice ending.
Agreed
You should have Juliet Floyd of BU on your podcast. Leading scholar of Wittgenstein and an amazing speaker. Big fan of your podcast, and it would be amazing to see her answer your spot-on questions.
Great suggestion!
Oh My Gosh.... I like your t-shirt and the pod-cat a lot...! You both remind me of a couple of my professors from uni (I've attended a few) and wow, I love it. Thank you for sharing. I think you would get along quite nicely. A couple of maths professors (Arvid Siqveland, Johannes Kleppe) or my professor in aluminum welding etc Medhi G. Mousavi.
Nice!
Thank you!
@49:00 this is where many people go astray (which, don't get me wrong, is a _good_ thing, because cutting edge science needs explorers). Quantum theory is a framework for analysis, it is not ontology (at least not _necessarily_ ). It employs measurement propositions. But the thing is, those are a way of talking about otherwise pretty classical systems in the background. In QM you "give up" on knowing the classical variables precisely. But you are never compelled to say they are not real. You instead are compelled to say we cannot measure certain sets of them simultaneously, plus, they exhibit entanglement.
But since ER=EPR offers a GR way to "explain" entanglement, you begin to see QM is just a subtle form of classical mechanics, with clumpy spacetime topology. What about superpositions on top of entanglement? Well, I am not sure they are different phenomena, but if there is non-trivial topology at some scale, then below that scale there will be closed timelike curves, so on that scale there will be effective superpositions. These are not SOH. SOH is more statistical --- accounting for the potential of all paths. Whereas the topological geon ER=EPR picture is that any paths may occur, but we cannot know which from past light cone data. Hence we are forced to use some non-Kolmogorov statistics.
If anyone wants to help me develop such ideas, it can be a lot of fun, contact me here: See t4gu.gitlab.io/t4gu/philosophy/ for some serious related fun musings. I just do this as a hobby these days.
@1:33:00 Fay's "birth of spacetime atoms" idea for linking to the hard problem of consciousness is reminiscent of George Ellis' Crystallizing Block Universe (CBU). He'd also be a good guest.
Not that I endorse those ideas. None of them have anything whatsoever to do with subjective mental qualia (the actual Hard Problem qua Chalmers). To be clear, saying consciousness is a process is a cop out of William James proportions (people have made that cop-out since forever). A process has no subjective mental qualia. You have to explain the subjective qualia. To my knowledge no one ever has. Not with any science or math concepts.
The only folks I know who remotely come close are poetic, that's merely because poetry and metaphor are imprecise, hence can at least have some pretense of completeness (as in, "Sure mate, there is a God, but I have no friggin' idea what It is."). Science seeks precision but not completeness. When will scientists realize Gödel essentially said no science based on precision (hence mathematical) can ever be complete? That's not to say consciousness cannot come under the remit of scientific precision some day, but it is a good reason to guess it might not. Which is only to say, less hubris please, when scientists try to explain consciousness.
It’s real, but we have no idea what we are doing , 😂, point is we at least try. Thanks for the steady stream of amazing content RE
Thanks!!!
We force space-time as a block into the small, and the universe complains by spitting out probabilities, because at that scale there is no space-time yet, it emerges, so the answer is: these are the possibilities that can be realized.
It was in 1995 Stephen Hawking & Roger Penrose The Nature of Space & Time
The duality of matter and the emergence of matter overlooks the substrate upon which matter exists, space. Materialist perspective is a philosophic substrate with little to assist your understanding.
Can you get Xiao Gang Wen perhaps and Subir Sahdev to the podcast, could be a great convos. Xiao is Ed Witten student, working on topological order and spin liquids
Quantum non-locality: would that mean that the extreme fluctuations at the Planck level is an indication of dimensional boundary say our Space/Time curled within a higher dimensioned membrane?
It looks to me that the strength of the path integral formulation is in its close relationship to experimentation. The way spacetime is inferred experimentally between A and B is by passing a particle from A to B. If there's no way to get from A to B, we conclude that B must not be part of the same spacetime. Because of the uncertainties involved, repeated experiments between A and B are required to build up a picture of the nature of the spacetime between them.
Also, another strength of this approach is that it's relational. It's stated in terms of relationships between A and B. So, a purely relational, relativistic spacetime, may take the same form.
In a discrete, atomic spacetime, I wonder if it shouldn't be composed of these A-B relationships, instead of points.
I think this is the reason why path integral formulations turn out to be so useful, it's because it's a good stand in for the notion of spacetime.
Instead of an infinitely divisible vacuum, path integral formulations build spacetime up from probabilities. Either theoretically, or experimentally.
Shouldn't there be some graph theoretical equivalent to causal set theory, in the same manner that the Church/Turing theses are related? I think causal set theory is entirely valid, but it may be treating the logic too broadly. A more physical system that can accomplish the same feat can be achieved with graph theory and some simple rules of evolution, I think.
There is also a way to refute SOH empirically, the Three Slit experiments (or N-slits for N>2). It'd be weak refutation, since those experiments are extremely subtle and rely upon near-field detectors, which introduce all sorts of possible spurious instrumental systematic and unknown errors. Standard orthodox non-SOH QM says a photon state can only be entangled with two slits, not three. But the sum of pairwise three-slit interference is extremely hard to empirically distinguish from extra interference terms from genuine three-path "exotic" loops.
@@Achrononmaster I don't know about that, it seems that there's a lot of different ways to approach a SOH problem that could produce spacetimes with all kinds of properties.
I'm trying to assemble a spacetime from component parts, and the kinds of paths I'd need for this formulation wouldn't be the kinds Feynman used, they'd be one dimensional, but would produce spacetimes of whatever number of required dimensions when combined.
So, this would be an explanation of where x, y and z come from.
The "paths" would really be in terms of timing differences, as in a pulsar timing array. So, spacetime as a quantum timing array.
Maybe it's too hard to get results from theoretically, but it definitely can be treated like this experimentally.
As for entanglement, ideally if you got the logic right, the right kind of entanglement would fall out of the equations. It's not adding together paths, it's adding together possible paths, so it should produce those kinds of effects.
On the other hand, I'm not against ER=EPR type explanations for entanglement, though I'm also interested in possibly modeling entanglement as a superluminal inflaton field. That would be handy in explaining inflation, dark energy and gravity.
also, try defining time as, Movement of the wave function, rather than change and you wont run into the parity issue!
this new definition can be turned into an operator which can describe both Newtonian and Einsteinian "time" as, if you were to freeze the system state, what would be frozen? more fundamental than change? all wave functions are frozen, this is Newtonian "time" (absolute) the system state is frozen in "time" no perturbations everything is frozen. this is the state of existence, Newtonian "time", then let the wave functions perturbate, you have the microstates perturbating outwards in 3 dimensions, this is Einsteinian "time" (local). movement of the wave function resolves both of these into their separate domains and says time is movement of THAT wave function!
the universal one of the sub wave functions. and all perturbate according to the local environment except the universal one, which perturbates at the speed of the universe.
@1:00:00 I think, all due respect, this is a fundamental misconception. Discrete structure has been around for thousands of years, the Greeks had that idea, then there was Newton, then Dalton, and many more in-between. But it is not spacetime that has to be discrete, it is the topology, at least for a first guess, which we need to consider as discrete. That is what String theory does. We do not need to set-up a discrete spacetime manifold for this. Ever heard of a pretzel? it's a smooth continuum structure.
So black hole entropy is not a clue about spacetime discreteness. It is a confirmation matter is discrete. But matter is not spacetime itself per se. Consider the Clifford algebras: they employ continuum spacetime, yet contain the discrete structure in the form of the irreducible representations of the symmetries. Why do such irreps. seem to exist in nature? No one really knows, but it has to be either fields "living on" spacetime, or the topology of spacetime itself (so a version of string theory or similar). None of which require discrete space, and yet which account for BH entropy (for minimal models at least).
When I say "fundamental misconception", I mean logically. It could of course be true that spacetime is a discrete structure. But black hole entropy is no proof or hint for this conjecture.
I think it's easier to make spacetime discrete. Why do you object?
This a very hard topic to do a podcast in question-answer form. You did a commendable job. Since the work is about establishing the concepts, asking questions in a topic where concepts are not well established is extremely difficult.
Spacetime volume being invariant was a very good starting point for me for modeling a continuum with a causal set.
@35:00 you ask her a great question. The thing is, in classical GR we can have discrete structure, namely the ER=EPR type proposal you alluded to before which Fay rudely dismissed ("highly skeptical" - why?? prejudice and pettheoryitis? She is dissing Susskind for heavens sake!). There are dozens of theoreticians now who use Clifford algebra to get the Standard Model symmetry structures. Those are discrete structures, but fully compatible with GR, provided spacetime topology is not trivial. Why should it be trivial topology though? There is no good reason for that presumption except to avoid closed timelike curves. But clearly it is at Planck scale structure where topology is non-trivial. So that is a terrific conjecture to explore - why is non-trivial topological structure (hence CTCs) restricted apparently (empirically so) to around the Planck scale? You have to at least ask before dismissing the idea. But once you open that door, then discrete structure (homology) is possible with the spacetime continuum assumption (smoothness, not finiteness nor Finitism). This entirely, I think entirely, eliminates any need for a finiteness physical assumption. Newton beats Zeno. At least by any parsimony arguments.
I mean to say... c'mon!! Finitism is a mental disease coming from _legitimacy_ from computer science culture. But physics is not computer science. So, imho, Finitism is not good science. You can adopt Finitism once Nature reveals herself to be finite. But quantum mechanics reveals no such thing, yet. (I appreciate I am in a minority here. But all the more reason I need to protest. I do not think I am _obviously_ wrong.)
Finitism is a relatively recent phenomenon, and it did arrive at around the same time as computer science thinking.
However, I don't think this idea is so much from computer science as it is from observation. It is a universe with a minimum, Planck scale, and an apparent maximum, cosmic microwave background scale. These scales were established relatively recently in the scientific past, and the implications are still being absorbed. It's an apparently finite universe that won't live forever.
I've had some computer science training myself, and I can give you my perspective on it.
Computer science is probably misnamed, and the field has some problems. A good computer scientist will recognize that what they've been studying isn't science, it's a form of mathematics. Then once they've realized they're not scientists, they're mathematicians, the good ones will also realize that most of their classmates aren't serious mathematical researchers, they're future IT trolls in your local dysfunctional bureaucracies.
The math the good ones study, though, is a very important branch of pure math. They'll learn all about Russell and Goedel. The study of algorithms is ancient, and has applications well beyond programming a computer. You can program your business into an assembly line, for example, or you can program entire societies! (That sounds sinister...)
Which is to say, there's some real insight from a certain section of computer science about the nature of language and mathematics. Considering how much language and mathematics contribute to the scientific enterprise, I think it's worth enlisting this perspective when it's the applicable one. Otherwise, you're mostly right about them.
If I had my way, I'd split the field into computer math (but a fancier name), and computer programming. Move computer programming into the arts department, and it can take some funding with it. That's probably where that (programming) belongs if it's to be taught at University.
Causality poses a problem in the context of entanglement, and in quantum mechanics in general, where true randomness is of the essence. For This reason, causal set is not a quantum gravity theory. It is purely classical.
There's no real division...they are labels... and I would say sometimes get in the way as the trees don't let us see the forest...
or what they had for breakfast...🤣
A new thing I think I've learned from this interview is that this particular Hawking student doesn't like Lenny Susskind. She explained the "ER = EPR" paper and idea without mentioning its author
Maldacena first had the idea er=epr and wrote that in an email to Lenny (per Lenny )
The ER=EPR is still a controversial idea.
Not everyone finds it convincing.
The same with the idea that conjectures some correspondence between quantum complexity with the growth of the interior volume/ length of wormholes/ black holes.
Interesting ideas, but still are hypothetical.
@@dimitrispapadimitriou5622 Sssshhhhh! fffs. Don't tell anyone ER=EPR is good stuff... or _not_ good stuff. Some of us want to fantacize we have a virtual pinky finger on a Nobel Prize.
The hard problem of consciousness is a materialist idea that disappears when the notion of the brain causing consciousness is dropped a-la Hoffman.
She has a very high blink rate when speaking about casual set theory compared to when speaking about mature theory.
Dude, you're lucky that me and people like me still watch your podcast. I lost respect for you severely after watching you talk s*** about Graham Hancock and Randall Carlson. They are not pseudoscientists lol and they are not anything to be made. Fun of. You seriously discredited yourself to a lot of people on that episode
I think you have it backwards. They are not even pseudoscientists.