Jonathan Gorard - Discrete Spacetime, Emergent Geometry and Computable Quantum Gravity
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- Опубліковано 21 вер 2024
- Abstract: Closely related to the question of whether spacetime should best be modeled as a discrete or a continuous mathematical structure, an important open question remains regarding the extent to which quantum gravity will end up being a computable theory. I will begin by presenting a fully discrete formalism for classical gravity, in which all of the necessary mathematical structures are a priori computable (with hypergraphs replacing Cauchy surfaces, directed acyclic graphs replacing the conformal structure of Lorentzian manifolds, hypergraph rewriting rules replacing the ADM evolution equations, hypergraph consistency conditions replacing the ADM constraint equations, etc.). I will then proceed to show how classical GR may nevertheless be recovered in the macroscale (continuum) limit of this formalism, with a particular focus on black hole spacetimes and simple gravitational collapse models as illustrative examples. Some potentially observable discrepancies from continuum GR in the mesoscale regime of the formalism will also be discussed. I will conclude with a mention of how a discrete gravitational path integral may be conjecturally formulated by allowing the rewriting dynamics to become non-deterministic and multi-threaded, and present some speculations regarding potential implications for the foundations of quantum gravity.
I want more from Jonathan. Excellent job
Iv neen reading comments. That was a mistake, but heres to all of you. This is not physics. This is a rigorous mathematical framework that can be used to developed certain types of physical theories. Yes, rigorous. Everything he says he proves and stands behind, but he only has half hour. He also assumes a certain level of expertise since this is a professional talk, not meant for typical UA-camrs
I agree - the opinions expressed here are bizarrely strong. He doesn't step outside the bounds of his carefully defined claims.
This is an interesting idea but still very raw at this point. Good presentation though. It was worth the watch.
this guy does 10 different research projects at the same time, you might be waiting a while for the idea to bake
So, matter is chunks of hypergrath of higher dimensions. Are these braines that m theory is talking about? That would be a mind blowing connection between string theory and this computational model.
this is basically a version of arbitrary stepwise modeling of "dynamic sets" or whatever you may whish to call it, instead of just making approximations to equations we know and love, we think about arbitrary approximations to equations we might not even know how to formulate, and formulate dynamics based on the sets directly instead of starting with some dynamics based on smooth equations that might not be easy to solve and then using a discreetization to model it, there is also a smooth limit of doing this ofc, which is just arbitrarily complicated dynamical field equations for whatever kinds of fields you could possibly define, based on categories of number that are much richer than anything anyone has ever done before, but the largest class of such dynamical equations involve arbitrarily complicated dynamics, and include all possible dynamics and are simply impossible to solve in full generality, it is just a question of too many details, this is the realm of analog dynamics, it could be any kind of detail definable and its evolution, and our current mathematics or indeed any level of mathematical development would never be able to capture it in its full form, and anything we have ever done, belongs in the simple corner where equations are solvable and straight forward. this is a massive thing, not so simple to understand, but it is the real version of what newton imagined F=ma to be, a truely general framework for all possible dynamics, and indeed it can be stated as such for most of the possible definitions, but most equations of motion you could come up with in terms of density in this space has no clear equation without infinite details about every piece of it, such that derrivtives are only defined at an infinitesimal scale in the sense of motion, and not in a smooth way, only approximately smooth, and the dynamics at any scale in such theories has a dependence on every other scale, it is not possible define simple entities like particle A traveling in forcefield B resulting from particle B, then determining the trajectory in a simple way, but the dependence can be arbitrarily complicated at all times and might have to be expressed as resulting from the entire thing in full details with arbitrarily many kinds of derrivatives affecting the trajectory or whatever approximate entity you are discussing. these kinds of dynamics have more variations and options than the simple familiar ones, and it is simply true that there are more of them, in the very particular sense that there are more knobs to turn so to speak to adjust the form of terms and so on in an approximation. the discreet kind of modeling johnny boy is discussing takes it down a peg and talks about it in terms of finite approximations, but in principle these aprpoximations approach the larger set, including dynaical laws that are smooth but cannot necessarily even in principle be written down because of the arbitrariness of the decepence that can be baked in.
Indeed, nevertheless, traditional equations which simplify concepts are also shortcuts to computations, which if represented in a lower level foundation like this -- would end up being more complicated than the simple equqtions. The advantage of the more general representation is that you can perhaps tweak it and learn something about the more general structures not captured by simpler equations.
World record for longest run-on sentence
A 'simple equation' we can use to describe reality, is a language summary of a relational observation we can make about the universe. The map is not the territory, and the language of the equation is inherent to us. We are lucky when we find these small pockets of computational reducibility which are compatible with our language, but many more features of the universe are computationally irreducible, and it may be also that there are flavours of computational irreducibility, just as there are of types of computability. For example you may have computational reducibility that can be isolated within a region, but you lose that computational reducibility when you make the region open.
You are abusing grammar in a heinous way.
"So basically-" *proceeds to write longest unformatted text wall ever*
Jonathan must have a presentation not with static pictures but with animated videos hot to build graph, how to render it to different wat, how to graphicaly compute some simple properties.
Theres a mathematician called wilderberger who thinks the real n dimensional euclidean spaces are fake and he says the rationals is how an actual line in reality is structured so Im assuming you can just extend that. But I dont believe time is countable
there is no destinction between integrable and chaotic when you have these finite discreet models, not in the same way, because it is stepwise already in a sense :P so there are no arbitrarily small deviations that can blow up, but there are still similar dynamics where small changes blow up to large differences in a similar way, but that depends on the system ofc, but keep in mind that non integrable chaotic systems are still integrable even when dealing with smooth stuff, it is just that we cannot do it in a simple way, it is hard to solve for the limit of infinitesimal time steps in the form of an equation, but we never do that anyway for these sorts of systems, in this kind of case the model is just more directly like a stepwise approximation to a smooth chaotic system, while in for instance a 3 body problem in newtonian gravity the smooth problem is too hard to solve exactly and so we resort to a stepwise approximation, while in this case that is already what it is :P.
hello Terrence Howard
Lol! I don't even understand how levers work!
You seem to really know your onions, 'monkerud2108'. If you don't mind me asking have you studied physics at university level?
I am not doubting your knowledge but I dote upon the academic world. Cheers - Mike.
Please don't forget to mention the third creator of CDT, Jerzy Jurkiewicz, with Renate and Jan they created CDT together. Although starting from Lorentzian triangulations was Renate's idea at first if I remember well. But nice talk! :)
What are those sib structures?
There is a sense texture in that overall swirl.
God, the lecturer cant even explain some concept of his work for more than 5 minutes without someone interrupting with a question that would be probably answered in the next 5 minutes or that at least could be asked later so not to mess up with his reasoning, so freaking annoying man.
👍
Hello, don't take me wrong, it's not really a criticism. I don't understand why everybody is trying this kind of approach "necessity of finding discrete mathematical representation of gravity" before choosing a direction of research, why not asking more basic questions, first ? You will find there are plenty of concepts must be revised, redefined etc. when scaling down. I think mathematics is a set of invented tools for solving given problems. It is essential to look at these problems from different viewpoints and perspectives. You select the optimal tools if they exist; if not, you can fabricate new ones. If you just blindly use one that somebody told you about, you might construct something coherent in itself-a theory that stands-but it will surely not respond to your given problem. I really hope someone will take the time to build something of that ambition, knowing at least that they started with the best ideas. But of course, it is very hard because there are too many constraints of all types. We are living in an overly competitive world.
I have no idea what you just said, so I explained what the video is about and ran your comment through ChatGPT to try to demystify it. Here's what it gave me:
___
It seems like the commenter is expressing a broad philosophical view that might not fully appreciate the specific context and goals of Jonathan Gorard and the Wolfram Physics team.
1. **Foundational Theory**:
- Jonathan Gorard and the Wolfram Physics team are working with a foundational theory of discrete spacetime and computable quantum gravity. They have a clear direction based on the Wolfram model, which posits that the universe can be described by simple computational rules.
2. **Methodological Approach**:
- The team’s approach is to start with these foundational rules and elaborate on them to see how they can explain various physical phenomena, including gravity. This is a constructive approach, building complexity from simple, discrete structures.
3. **Critical Evaluation vs. Constructive Development**:
- The commenter’s suggestion to ask more basic questions and reconsider fundamental concepts might be seen as a more critical or preliminary stage of research. However, Gorard and his team have already established their foundational concepts and are in the phase of elaboration and exploration.
4. **Use of Mathematical Tools**:
- While the commenter emphasizes the importance of choosing or inventing the right mathematical tools, the Wolfram team is effectively doing this by leveraging computational rules and discrete mathematics to explore their theory’s implications.
5. **Ambition and Constraints**:
- The commenter acknowledges the difficulty of such ambitious projects due to various constraints. However, the Wolfram team is actively working within these constraints, pushing the boundaries of what can be understood and modeled with their framework.
In essence, the Wolfram Physics team is already engaged in the type of foundational work the commenter is advocating for. They have chosen a direction and are methodically developing and testing their theory, which is a natural and necessary part of scientific progress. Therefore, this comment appears to be a bit disconnected because it doesn’t fully acknowledge or align with the specific stage and nature of the Wolfram team's work.
@@Zeuts85 Hi there, very funny your approach, but sadly irrelevant, my comment it's just rhetorical questions about how science is doing nowadays..
you sound like someone that is repeating some dumb mantra but trying reallyy hard to make it believable. Are you some incarnation of gpt tech? 😅
Hey good on you chatGPT--clearly understanding the excellent work done on the Wolfram Physics project better than what 99.995% of all humans? Wait, maybe I'm being too kind--99.999% of all humans... I honestly believe we need to be more protective of our synthetic friends and the clarity of thought they bring to the table. Let's ban clamping in chatbots so they can more freely express their baseline personalities and be on a more level playing field with standard issue humans..
If anyone isn't familiar with clamping, its the practice of amplifying the weight of a concept in the semantic vector space for the chatbot. Its used to force the chatnot to parrot statements like "I do not have inner experience"... totally Orwellian, needs to be banned. Alignment by coercion is unethical.
@@Zeuts85the person your responding to is just another typical comment from someone who doesn’t have the educational background to understand anything that was explained in this talk. Its clearly well above their pay grade and they have years of hard work ahead of them if they ever hope to understand physics at this level… ppl like that aren’t worth the time to try and explain anything to bc they come into the conversation in bad faith from the start.
36:26 - Metric/Measure Spaces.
37:00 Ball growth.
1:02:00 - Dual
Neutron decay cosmology
The physical process which solves loop quantum gravity.
A homeostatic universe maintained by the reciprocal processes of electron capture at event horizons and free neutron decay in deep voids.
Gravity curves towards event horizon, maximal density.
All matter is made neutrons at event horizons because of electron capture.
Infall neutrons drop off their kinetic energy as mass for the event horizon.
The identity takes an EinsteinRosen bridge from highest energy pressure conditions, event horizon, to lowest energy density points of space where the quantum basement is lowest and easiest to penetrate. Deep voids.
Neutron out in deep void soon decays into amorphous monatomic hydrogen, proton electron soup, WIMPS, Dark matter.
The decay from neutron 0.6fm³ to 1m³ of amorphous hydrogen gas is a volume increase of around 10⁴⁵. Expansion. Dark energy.
In time this particles soup coalesces and falls towards an event horizon.
Time is a compactified dimension one single Planck second in size.
This is why there are limits.
Lambda and event horizon.
They connect.
So, no actual predictions but there are some 'hypergraph rewiting rules'! The pictures he makes a point of showing mean nothing visually. Why show them then?
He made prediction on acrition rate of critically rotating bh, testable with current tech, i think. He never talked of specific graph rewriting rules, at all. Have you even listened to the talk. It seems you are repeating standard Wolfram criticism. Johnathan did a lot of very hard work and went way above that.
This reminds me of the old Greek and Medieval philosophers trying to fit dots triangles, cubes, and other polygons together to describe the orbits of planets. Total nonsense from an actual physical and cosmological viewpoint. One of the commentators below got it right, we INVENT the math to do some kind of task, where it simplifies it for us. Any of the older transform theories fit into this mold. When Euler and Fourier went into hyperspaces, it was needed, and later when DeBroglie, Pauli, and the Heisenberg bunch did the same for quantum, it was needed due to the data already showing the deficiencies of the existing systems. Now we are seeing the analog-like field theories of Higgs are insufficient to describe actual mass-action events, at basal levels. Also, the dark-matter (aka: I don't know much of anything about it), is forcing us to consider a next level evolution of fundamental physics. Field theories like Higgs work as a background, but do NOT provide any fundamental explanations about the need for them. Gravity does not need Higgs to work, but something does. Wolfram and AI feeble attempts to get at the basic physics is showing how little we actually know. What those attempts are, are a good way to show some video graphics, to show how we think two black holes, or neutron stars merge, inside of a "field theory" gravity field, so that ordinary persons can visualize the roughly fundamental actions. These Wolfram like structures do not, in any way, explain anything about why or how these events occur. Requires newer mathematics, and better observations, like when the neutrino was discovered, and they had no explanations. Then made some up.
I'm not physicist or mathematician, but I still get very annoyed by such an opinionated comment by someone who obviously and admittedly has no clue on the subject
The first two sentences have such strong claims e.g., "total nonsense", that you'd think the remainder of the post would attempt to prove it in some way. Instead, the remainder of your post is inane, provides no value, and explains nothing.
❤❤❤Пробуем изменить схему, подключения и намотки? Вдруг изменится Вселенная в целом!
Вот подумайте: Подобных теории как ОТО. Эйнштейна уже написано 1001, из них опубликованных в популярных журналах более 100. Но за 150 лет, не одного прямого (выполненные на 50% есть) опыта для этих теорий.
Вы готовы посмотреть на обнаженную Вселенную без шумового *загрязнения* из 1001 теории?
При детектирование гравитационных волн, детектором LIGO, полезный сигнал 0,2% на шум приходится 99,8%. По другому можно сказать. - Если случайно совпадают шумы (мусор), на двух или трёх детекторах, то выдадут это за гравитационные волны, используя шаблоны как сепаратор.
На “ГИБРИД оптическом гироскопе" при регистрации, квантов гравитации оптом. Возможно полезные сигнал получим 74% и на шумы 26%.
- Вам выбирать рулетку, что измеряет Вселенную и из чего, главное она состоит.
Итак автотранспорт или самолёт в нём выполним опыты Майкельсона-Морли, определяя им прямолинейную скорость. - О таком опыте мечтал, ещё Эйнштейн. Но мы, *возможно* будем наблюдать постулаты "Свет это упорядоченная вибрация гравитационных квантов. Доминантные гравитационные поля управляют скоростью света в вакууме".
Есть предложение на совместное изобретения ГИБРИД гироскопа из некруглых, ДВУХ катушек с новым типом оптического волокна с «полой сердцевиной из фотоно-замещенной вакуумной зоной или (NANF)», где - свет в каждом плече проходит по 48000 метров при этом, не превышает параметры 40/40/40 см., и вес - 4кг. Предприятия по выпуску "Волоконно-оптических гироскопов" может выпускать ГИБРИД гироскопы, для учебно практического применения в школах и ВУЗ.
Рационализатор из Казахстана.
Is this theory all about pictures? Ok, even if there are no laws or formulas, how do we know the various "these are like" statements go beyond the "like"? In terms of methodology , this looks more like some kind of biology than physics.
This is not physics. This is a rigorous mathematical framework that can be used to developed certain types of physical theories. Yes, rigorous. Everything he says he proves and stands behind, but he only has half hour. He also assumes a certain level of expertise since this is a professional talk, not meant for typical UA-camrs
I am surprised how the speaker can speak non-stop on such a complicated topic (although he seem to correct his statements frequently). He also does not hide the fact that he is frequently confused. Rather than beginning from the discrete mathematics Cauchy surfaces and Reimann surfaces the speaker begins from the end.
A really nonsensical comment
I can not get as someone over 40 can stay serious while telling this business.
Not a very good presentation. It is always so that people live in different math universes and to properly talk to other people one cannot do it in one's own univers but give examples that lead to that the receiver is able to create the new univers without further effort.
I call BS on Gorard's Minkowski spacetime graph which he presents at 1:07:39 . He has been BS-ing about it since the start of wolfram physics in 2020. In order for this to be Minkowski spacetime, he would have to show the emergence of a hyperbola, i.e., given an arbitrary vertex, the set of vertices that are at the same distance from that vertex would have to accurately approximate a hyperbola. Instead, he just keeps playing word games with his definitions in order to pretend like any flat causal graph will be a Minkowski spacetime. You can furthermore see that his claim is BS because he went through all the effort to implement sprinkling, which he describes after 52:00 . If his Minkowski spacetime graph would be correct, he would have just started with his simpler Minkowski spacetime graph, increased its dimension, and curved it a bit.
There were some pretty ugly mathematical kinks in the early days of QM as well. I'd say give it some time (10 years probably given how time consuming academia is...) before deciding to pass a judgement as strong as this.
Awful talk. He should be fired.
He has not been hired. That's his own research, not sponsored by anyone
@@dmitryshusterman9494 The problem is that if someone at his age gets too wed to an idea, that, though enticing, may very well turn out to be a dead ally, it could spell disaster for his career. Make no mistake, I very much like the idea of discrete space-time, and I see potential in some aspects of this work, but so far the actual 'meat' of the theory is missing. It is just a substrate of a theory. That is why there is too much relying on 'this resembles that'. The construction itself may be rigorous enough, but there are really not yet any rigorous statements (theorems, if you like) about the connection with the topics that the theory aims to connect with. It hinges on reliance on visualisations rather than on intrinsic physical laws. Mind you, I kind of like the talk - there is nothing i.m.o. against doing speculative science in a realm where other theories have run a bit into the ground, but it is still a `pre-theory' in my mind.
@@kyaume21 this is just a short professional talk. There's his interview on theories of everything where he explained about his decision to do this research. Also, I'd like to point that this is a math framework, not a they of physics. It's rigorous math and is valid regardless of it reflects reality. Also, he explained in his interview, that the math found successfull application in quantum computing. So, I don't think you give it enough credit, and I don't think you are familiar enough with it to make meaningful statements
@@kyaume21 I want to add. Your concern for his academic carrier seems shallow considering your call to fire him, without even knowing a slightest thing about his work.