I’ll be honest, pbs space time taught me that there are boundaries where meaningful learning disintegrates. If you actually start learning the technicalities, you find that goes little beyond the math…. Constantly pondering what ifs is rather pointless….
They remind me of how much I may never learn with how much there is to learn, because behind every door of new discovery we open up, there's a hallway of locked doors to try and unlock, in order to see what's behind them!
PBS is one of the reasons I decided to study physics, currently struggling with classical mechanics, but I won’t give up, the goal is a PhD in physics, thank you for keeping up curious ❤️ Edit: I have passed the module, I’m now doing a physics and pure maths double major for my final year, next update will be graduation. Thank you for all the positive messages.❤️
Piece of advice from someone who wasn't able to make it work for me. Don't over pack your schedule. Take the time you need to actually learn and understand all the things that are relevant. All the math classes are relevant even if you don't see how it could be used in the present. Good luck!
This show is such a gift. It strikes that perfect balance of technical details and concepts while not totally abandoning those who don't work in the field.
Nothing makes me happier than finding a new episode while winding down body before sleep. This channel is pure bliss. Also Matt is a fantastic narrator ❤️
You and me both🤞🏾. Whenever my body is at 1%, Im on a mission to find that ideal video to drift off to sleep. Their content is like a soothing treat 😴😴
Space can come into existence without using a previously existing ingredient (Prathya), and also, space element (Akasa Dhathu) emerges from the 4 existing ingredients called Aharaja (foodly molecules), Cittaja (mindly actions), Wruthuja (weatherly elements), and Kammaja (reactionly entanglements) according to the Buddha's teachings. Form is emptiness, and emptiness is form. Probably, the two forms of emptiness can behave like space (free points of space) and counter space (solid points of space). Space could increase due to the unstoppable flow of the absolute time from negative time (from zero-infinity) to positive time (to infinity).
The analogy of foamy spacetime also serves to explain what I mean when I answer with "nothing" to a "what are you thinking about?" question. A bunch of virtual thoughts and anti-thoughts, altering the geometry of my mindspace. The fluctuations are there if you look close enough, but from a broader perspective it looks perfectly level. In other words: *no thoughts; head empty*
Too humble. Your 'nothingness' is what most people lack and should envy. You are very good at self-observation. This very deduction of yours can be labeled as 'Hawking radiation' of wormholes. (inside your not-so-empty head) 😊
Man, the writing in these videos is INCREDIBLE. The way you explained the heisenberg uncertainty principle in combination with GR in such a easy to understand and logical way for people who dont have university level physics education is mind blowing. There's no where else on youtube where you get such easy to understand but in depth videos on such insanely complex topics :D
The writers are excellent at writing an easily understandable presentation, not just Matt. People like you are the reason there's a writers strike presently taking place.
You know you've been watching spacetime for a while when you know who Wheeler, Feynman, Thorne and Everett are and what their contributions were to physics. 6 years ago, I would have had no clue.
That's great you learnt something from him & if learning physics makes you feel happy but, never forget the fact that Science is nothing more than the study of phenomenon/ process/ know-how which is perceived by our limited knowledge, intellect, understanding and senses like hearing and seeing ability. And Ideas/Theories are proposed by observations which are perceived by our limited senses. So, when a Programmer elaborates the importance of Binary Numbers/ Language Code of the Computer & explains (know-how/ phenomenon/ process) how a Machine/Computer talk then it does suggests us that there is a Programmer /Designer behind a computer. And, a human body is one of the most complicated machine on Earth let alone if we talk about the Universe which is much bigger and complex than our DNA 🧬 A Unique Program/ Instruction Manual/ Code).
I was watching an older video and paused it to come to the newest video comment section because it's new. Anyways I just wanted to thank this channel. I started watching it and although it interested I didn't understand much of anything and couldn't grasp some concepts. After a year and a number of youtube videos later I really feel like I'm starting to understand this stuff alot better. I'm now able to follow along and not be completely lost. The most I took in school was grade 9 physics and it didn't interest me at the time. Now I'm 34 getting into physics, and my only regret is not learning this in school. Thank you PBS spacetime.
I want to thank the writers for their efforts in making this an easy listen and Matt for his oratory skills! It's always a pleasure to tune in and learn about this fantastic cosmos we live in. You guys and gals ROCK!!!
I've been watching SpaceTime for years and never known who's actually writing the episodes. I'd love to find out, whether it's Matt, a writing team, or some combination.
this show is such a great contribution to science education and humanity, you take us on the ride of modern physics without needing us to do the math I apprentice your choice of words that convey the innate uncertainty of all scientific theories while recognizing all the work that went into our current understandings It's just a perfect channel and I wanted to thank you for your service
I'm increasingly uncertain about the amount of beer I actually have under an alarmingly large expanse of foam. I guess only time will tell how much empty space I am left with once it settles.
This theory explains so much and even though it hasn't been tested it has that intuitive quality of beauty that correct theories tend to have. Thank you Matt for your excellent presentation and graphic illustrations.
Reminder episode starts with a What IF part of series that starts with What If Space And Time Are NOT Real? Note Quantum Mechanics is extremely non intuitive to the point human brains have trouble. And I have intense trouble understanding Relativity as in how it truly works. Plenty of beautiful incorrect theories.
@@milferdjones2573Quantum þeory becomes very intuitive once you realize it's just ðe equilibrium case of Bohmian Mechanics. Ðe latter þeory has just two ground axioms: Schrödinger's Equation and ðe Guiding Equation. Everyþing else follows from ðese two. BM can wonderfully explain ðe measurement problem wiðout invoking any mysterious, ill-defined, or non-physical concepts.
Another stellar episode gents. This one really made it click for me why an empty vacuum would have non-zero energy. Turns out it's that pesky uncertainty principle at work all along, except for geometry itself, that would never occur to me. Big shoutout to the whole production team by the way. Matt is such a treasure to listen to, truly the David Attenborough of physics. The animations make it really easy to grasp what Matt is describing by visualizing the effects. This time in particular they were helpful to intuitively understand the effects described and looked really cool too. It's a real privilege to be able to learn so much about the natural world, this type of knowledge was unheard of for most people until just a few years ago. Now it's accessible to the common layman like myself who have a curious itch to scratch when it comes to the underlying workings of the universe. I am not sure if you guys are aware how important the work you do is, but just know it means a lot to people like myself. So thank you for your efforts and may many more stellar PBS Spacetime episodes air on this channel.
5:00 Be mindful that the Heisenberg Microscope makes it easy to confuse the uncertainty principle with the observer effect. One can argue in this vein to show the trade-off in uncertainties, but it makes it easy to mistake any uncertainty for a product of a measurement, rather than an intrinsic property.
Yeah, the Heisenberg Microscope makes it way too easy to conflate those. Do you know of any (relatively) easily imaginable analogies or thought experiments that help us to distinguish the two (purely epistemic uncertainty vs. Fundamentally Real metaphysical uncertainty)?
@@harmonicpsyche8313Yes, on this very channel there was an episode called "Breaking the Heisenberg Uncertainty Principle" that explained it beautifully.
Can you put up a 10 minute repeating video of that quantum foam? It was oddly satisfying and relaxing. Bonus points if the audio is Matt reading his favorite physics paper.
Imagine sailing in a boat of size of a peanut through an ocean with waves higher than a skyscraper for 40 billion years. And then astronomers catch you and say aha, this fella must have been emitted by a helium atom from galaxy GE-5576 around a million years after the Big Bang.
about two weeks ago I was watching multiple people play in a swimming pool independently and observed the rhythmic fluctuations of the water. I was imagining the people as particles and the water as space, so this analogy felt very intuitive to me. super cool!!
There was a lecture leonard susskind gave where he said that quantum entanglement appears to be the thing linking different regions of space together. Highly entangled regions are closer together and weakly entangled regions are further apart. It was a possible implication of the ER=EPR paper that draws a connection between the wormholes of GR and quantum entanglement. As I understand it, theorists discovered that 2 entangled black holes (2 sets of entangled particles compressed to form 2 black hole) can be equivalently described using the Einstein Rosen bridges of GM and using the entanglement of QM. You can model the 2 black holes as being connected by a wormhole or as being quantum entangled and you get the same results either way. Its as if they are just two sides to the same coin. This lead to the argument that if two entangled things can connect separate regions of space via a wormhole then maybe entanglement is what connects different regions of space in general. I dont know why, but I really intuitively like that idea. The nonlocality of entanglement seems to suggest it is possibly something more fundamental than spacetime
I just want to say that I appreciate how the titles of these videos seem innocent enough to hook viewers who might be more hesitant about clicking on more complicated sounding videos.
I watch this because one can learn some ideas. Learning from failures and dead ends often is illuminating. I don’t watch this because I believe GR is incomplete due to its conflict with QM. It is only logical that QM is also incomplete for the same reasons. If QM wasn’t incomplete, we would understand why the strong force is short ranged, why color confinement happens, the nature of anti matter, we would prove that hawking radiation is real and so are gravitons, and of course, we would know the answer to the measurement problem, moreover, we would know definitively whether non local hidden variables are possible or not. The dogma is sad and dangerous, but it also allows room for great discoveries to be made.
That just means you're learning! If you go back to earlier episodes, they'll likely actually click much quicker. Nothing wrong with feeling a bit over your head: it's what you do about it that matters.
The surest sign that a person does not understand Quantum Physics is that they think they understand Quantum Physics. Some people understand some parts of the subject, and know how to use some tools to study it. Not even our greatest minds understand all of it. If they did, they would publish their unified theory.
I'm fascinated by how some people's reaction to education about the outside world is to marinate themselves in how it makes them feel about themselves. Like, why do you need to make a value judgement? Just learn. You don't need to have already known about the things you're learning.
Quantum scientist here, love PBS Space Time, quick correction at 4:50: The Heisenberg uncertainty principle is not equivalent to the classical observer effect, where measuring a particle’s position disturbs its momentum. The quantum uncertainty principle tells us that the more well defined a particle’s position is, the less well-defined its momentum must be, and vice versa. It’s not that we can’t accurately measure both variables at the same time; the particle literally doesn’t have fully defined values for position and momentum at the same time (depending on your interpretation of Quantum Mechanics). This is unfortunately a common misconception, contributing to the general confusion as to how quantum and classical mechanics are different. For a clear explanation (and explicit confirmation that the two effects are not equivalent) I recommend your original video on the Uncertainty Principle!: ruclips.net/video/izqaWyZsEtY/видео.html
The explanation of Planck length's connection to GR's nature of energy distorting spacetime, and the connection to Heisenberg's uncertainty of the energy (uncertainty is equivalent with pairs such as energy/time or position/momentum) was a huge revelation to me. First time I got a physical intuition for where the "any traditional spacetime geometry stops at Planck's length" thing comes from.
I wish this would've been available when I was in school. I hope the kids know how good they've got it nowadays. Had to read all that stuff in books / pay attention in class / even do some homework sometimes
Matt, thank you! Your emphasis on spacetime "falling apart" at the Planck level helped me see a new and, I think, more quantifiable interpretation of quantum mechanics as an algebra of interacting xyzt instances created by varying-scale collections of closely interacting mass-energy parts. Each frame xyzt has a resolution, orientation, and... hmm, yes, a spin! Interesting... I wonder if some Planck foam maths might be relevant if rescaled attached to mass-energy limits? An xyzt instance algebra of multi-scale spacetimes that interact and rescale (collapse) each other, with the high-mass units tending to dominate, opens up new paths... Perhaps that's all collapse is: Joining the larger local Inertial Frame Club. Again, thanks!
Re the uncertainty principle--just because we can't know something, doesn't mean every extreme possibility is occurring. All the uncertainty principle says is we literally don't and can't know. Maybe virtual particles aren't real. Maybe there is zero energy at the Planck scale. Edit: It turns out it has been experimentally confirmed that particles can spontaneously emerge from a vacuum, however, the explanation may not require virtual particles.
You talk about particles ...may I ask what do you think they are? A particle is by deffinition a very specific localised excitation in a quantum field. Let's study the electron . We refer to the electron as a particle with a mass of 0.51 MeV and as being an excitation in the electron field. Everthing is made up by 1,2, 3 etc electrons, but never of 1/2 electron , or 3/2 electrons. That means that particles are quanta. Now, the punch line : When the electron field vibrate with the exact energy of 0,51 MeV or multiple of that number it will be a real particle , if not then its gonna be a virtual particle. For example: a vibration in the electron field of 0,71 Mev its the virtual particle. This process is happening in all the 17 known Quantum fields. When it vibrates with the energy numbers that you will find in the Periodic Tabel of Elements and integer multiple of those , then a particle will appear in existance. In all other cases, we call the vibrations of this quantum fields , guess what? Virtual particles !
Thank you for this episode! I don't think I've ever adequately understood just what the "quantum foam" of "empty" space is supposed to actually be like. This helped a ton! By the way, are there any plans currently in the works for a larger UV telescope than Hubble? God be with you out there everybody. ✝️ :)
I watch your videos instead of the Hollywood Sci-Fi abominations. This is some quality content here and your persistence in producing it is admirable. Keep going!
I've known for a while that the Planck length is the shortest meaningful distance, but I never knew why. Finally being able to connect it to other physics concepts is like a lightbulb moment
What I get from this is, that the planck length, rather than implying that there is a quantisation of size, is just a limit on what we can currently resolve. (Because of the quantised nature of the photon.)
My love for this channel is unmatched. With all the grand questions being asked, feeling insignificant and unable to ever answer many of our big mysteries - this makes me feel connected to whatever this universe is. So grateful for this information ❤
10:22 this is the first time I’ve heard that they can have negative mass. Everyone always says that they’re just “antiparticles,” which implies that their charge is opposite, when it is actually their energy.
I could be wrong but I remember hearing somewhere that virtual particles are not bound by he speed of light/causality. So, they move faster than light. Back on topic now; virtual particles have negative mass? Someone, quick, call Miguel Alvubierre! Tell him we found his exotic particle! The Alcubierre Drive just became one dyrp closer.
@@WolframHeart-xp2px See spacetime on virtual particles. They are not real like real particles and thus they don't have to comply with lots of parts of physics. They are approximations of what is going on not what is actually going on that we do not have clear idea of. Virtual particles can't be extracted from anything and isolated so can't use them to make the Drive work.
@@milferdjones2573 But, then what about the Casimir Effect? Isn't it related to this topic? Not that I necessarily believe we could extract virtual particles, but that at least a portion of physics suggest they are there is something nice to have. But hey maybe something will come from it one day, right?
The Casimir effect is a result of a more complex phenomena that can be more easily calculated using virtual particles. The virtual particles themselves are a nice mathematical construct, but they represent something real. In the same way we can treat alpha radioactive decay as a pre-exisitng particle inside the nucleus randomly tunneling out after bouncing around a bunch of times. The particle doesn't exist like that, nuclei aren't hollow shells filled with marbles, but the construct DOES represent something and radioactive decay most certainly happens.
One of my favourite things about science at this scale is that you can have a situation where you use technology to analyze data of stars billions of light years away to help find evidence for a theory about what time and space looks like on the smallest scale. Just wild, in the best way, but still.... Wild ❤❤❤
Could the theoretical small wormholes opening at the plank scale explain quantum tunnelling subatomic particles? Thanks as always Matt and the whole PBS team!
As a pedestrian mechanical engineering graduate student, I recognize a lot of descriptive similarities to the work I’ve done in turbulence research. Thank you for the video. I might have to watch it a few more times though!
That was a groundbreaking explanation. Not sure if I watched same explanation before, but linking uncertainty from Relativity and uncertainty from Principle of Heizenberg to the square of Plank lenghth was really amazing!
That idea has a name. It's called "Heisenberg microscope" and it's 100% false. The uncertainty that the Heisenberg uncertainty relation describes is NOT the uncertainty of an individual measurement. It's rather a mathematical phenomenon of linear operators over linear function spaces. You will encounter it every time you do a Fourier transform, even if that Fourier transform is taken over completely classical data that has no physical uncertainty whatsoever. You can find it discussed in textbooks on acoustics, geophysics, signal processing, it's part of your Wifi router's collection of algorithms and to a mathematician it's a trivial lemma in introductions to functional analysis. Why Heisenberg felt the need to build a fake physical model for it is unknown. He should have known better.
WHIM effects should be rarer but larger in magnitude and involve outright scattering -deflection of light in a totally random direction. In a sense the charged particles of the WHIM are like rogue waves on a choppy sea, following a separate distribution, one that can overturn even large boats. And we see such effects, as well as even more obvious effects from intervening clouds of gas. (The latter giving us the 'Lyman alpha forest' in spectra.)
I like this channel because there's always something ancillary yet relevant to the subject that ends up leading me down a rabbit hole. For instance the Planck length. It leaves me wondering whether the length exists because that's the minimum size of space something can occupy or if its just the minimum size we can detect. Then I wonder if we know our measuring photon is X wavelength, why not calculate and subtract whatever change it has on the gravitational effects of the space we want to measure. And I haven't even gotten to the main subject! Dang you PBS Space Time for these rabbit holes!
I seem to remember that this velocity/position measurement explanation was a misleading misinterpretation of the Heisenberg uncertainty principle. That the HUP has nothing to do with measurement and everything to do with the actual wave function, so that constraining one variable actually spreads out the possibilities that the other variable can collapse into. Was it not on this channel where I learned that? Edit: Yes, the PBS Space Time episode explaining it was called "Breaking the Heisenberg Uncertainty Principle".
In an earlier episode (can't remember which) it was discussed the black hole might not be able to evaporate completely. They might just sit at the plank limit. Wouldn't the idea of cosmic foam prove that not to be the case. Because if black holes were always popping up, the universe would just be filled with tiny black holes. Am I misremembering the episode or is something else going on?
Those would be two very different types of plank-scale black holes. The ones discussed here are in some sense "virtual" black holes, their mass-energy comes from the uncertainty of space. "Real" black holes that evaporate down to the planck scale would still have one planck mass of real mass-energy, that may or may not be able to evaporate, and if it can't evaporate it cannot return to nothingness like the virtual black holes can because of conservation laws.
Matt you are the best. i love being able to play sections over and over until my mind stop wondering off on some previous explanation, and i get the next one.
What i have been wondering about the quantum foam, is can momentum be imparted upon it? Does something near the speed of light have a wake? Does a rapidly spinning massive object deform the quantum foam?
Yes, it should. This is a relation to 'vacuum polarization' where the charge of a particle alters the vacuum. It would be a very weak effect and depend on whether we treat gravity as a particle-mediated field or a warping of spacetime. The latter, on larger scales, gives us 'frame dragging' and gravitational waves.
is this the most precise way to say it however? like is this the difference between active and passive voice? because the photon never "gains" energy simply pops in and out of existence, as mass is converted into energy, like photon
Great episode!! "The vacuum is alive keeping the divide between motion and stillness." Hiesenberg~ This quote of his is a beautiful explanation for the interaction between space-time, the vacuum, and the nothing.😊
At the beggining, you mentioned 2 possible "fixing" of Gravity & Quantum Loopholes vs String theory, but what about Verlinde's gravity or entropy gravity theory ? Could you make a episode on that ?
That water/foam analogy reminded me of a line from the movie Ponyo, "If it fails she'll turn to foam" "But that's where we all came from." Turns out Hyaio Miazacy is a bigger genius then everyone thought.
You know you’ve been watching/listening for so long when you can instantly tell that Matt has a wicked cold he’s pushing through 😂 Still kills it though!
@@noahwilliams8996Good point. Well, how about composite particles? They have a size (sorta. There’s uncertainty on the size. But whatever.) If the position momentum uncertainty relation is due to particles (having some amplitude of) going through wormholes, would we see the same position momentum relations for composite particles? Like, if the composite particles would be too big to go through. Hm, well, if the position momentum relations for the elementary particles obey the relations, that normally gives rise to the relations for the composite particles I think? Suppose composite particle comprised of two elementary particles with the same mass. Position operator of composite particle should be the average of the two position operators, momentum operator of composite should just be the sum of the two momentum operators. Taking the commutator... Yeah, that gives the canonical commutation relation for the composite particle. So, if the wormholes can explain the canonical commutation relations for the individual particles, then I guess it would explain for the composite ones as well... But... Does it make sense for it to explain the commutation relations for the elementary particles? Seems like it could contribute to uncertainty in position and I guess also momentum, but... could it explain the commutation relations? For that... Hm. Well, it doesn’t seem like it should in an instantaneous way at least? Like, if it were the case that “without these wormholes and such, position and momentum would commute”, then... well, then at any moment they would commute. But, if say, we let the position and momentum operators evolve over time (using the Heisenberg picture rather than the Schrödinger picture) then... perhaps the evolved forms of it could tend to have approximately the canonical commutation relation? This seems a bit far-fetched to me, but also interesting. It would be interesting to see if one could describe a system where position and momentum operators by default commute, but where after evolving for a long time under the time evolution, tend to approximately satisfy the... Oh wait. If \tau_t(A) is the result of evolving an operator A for time t, well, this should be an automorphism, so [\tau_t(x),\tau_t(p)] = \tau_t([x,p]) So, that can’t work. Not to say there couldn’t be any other way the CCR relation could potentially arise from said wormholes and such, just, I can’t think of any.
The water example would be better illustrated with underwater example in the end. We are underwater and don't see waves, it looks the same everywhere. The waves are only the "edge of the universe".
Would a better analogy for spacetime foam be a submarine passing through the water, either deep, shallow or surface? In deep water, the travel would be smooth, but still all encompassing- whereas the plane analogy creates a visualisation that implies a separation of the observer from the subject - which is impossible from our limited perspective. Just a thought - love the videos!
If you place an object into an environment with specific conditions, that object will either change to accommodate the environment or the environment will change to the accommodate the object. Same fundamentals as entropy and the three body problem.
First impressions: thanks to the video editors for not compressing/speeding up the audio on this video. The last few episodes were really annoying. *Edit: fascinating content, made all the more engaging thanks to Matt not sounding like a chipmunk.
This is an interesting idea and one that seems to resonate with many people. It's relatively simple concept. The closer you look at something to more fine details you notice. This can change things a lot. Most of the issue is we are looking at stuff from very far away compared to the plank scale and can't see the details. If we can find ways to look at this closer then we may uncover things like this foam. It is also suspected that light may not travel at C in a vacuum I heard lately. But that the difference is so small we can't see it. Very interesting concepts.
Thank you, Matt, for once again leaving me enamored with the wild possibilities of science. You continue to inspire me to keep learning and pushing for that next piece of knowledge. Another fabulous video and I do very much look forward to the next!
If something can not be measured, does it still exist? If a star continues to collapse until it reaches a plank length, what happens then? Does it stop collapsing?
Atoms existed before our ability to measure them #justsaying. A star would not collapse to planck length, the constiuent parts are too big. This is why collapse triggers massive outbursts of energetic particles
"More work is needed" Also as a biologist, this is the ultimate conclusion of so many experiments. The closer you look, the more complicated things get, and the more you have to look 😁
GR has more discrepancies in what we observe than quantum theory. That's why we see things like dark matter, MOND, the issues with galactic rotation speeds, and observations of galaxies that don't seem to fit any of the models. Quantum theory has its own issues like the vacuum catastrophe, but GR seems more incomplete based on what we observe.
@@Garresh1 Do you think the reason that this feels backwards to most people is that we (mostly) observe GR on our scale (humany sized things) as opposed to Quantum Theory (mostly Planky sized things), and this throws our intuition off of which one we're measuring more often, most accurately, or with the fewest discrepencies?
@@scottglajch1555 I don't think that assertion is correct, actually. The first confirmed observation of GR occurred during a solar eclipse when the position of stars was slightly shifted due to the light being curved. And within our solar system the only thing GR has any effect on is the orbit of mercury. Nowadays we have to account for GR with things like GPS due to the insanely precise timings. On human scales everything can be explained with newtonian gravity. Quantum mechanics on the other hand is something we deal with regularly even in our day to day lives, at least with our technology. Quantum effects *massively* affect things like CPU manufacturing and place limitations on cpu speeds due errors from quantum tunneling. Anything involving manufacturing on microscopic scales has to account for quantum effects. So while we have mountains of evidence for both, I'd argue quantum effects have a larger effect on our day to day lives.
@@Garresh1 Thanks. That make more sense than what I normally hear which always comes down to "We know that there is something wrong with GR because it does not play nice with Quantum theory." My suspicion is that most of this is due to the fact that GR is deterministic based on what is measurable while quantum is build on the probabilistic description of the immeasurable. Given that framework it is no wonder that they do not fit together.
I wonder if this distinction really exists? Like, of course both would be different. GR doesn’t have superpositions of states or uncertainty relations, and QFT doesn’t have a spacetime that changes based on the matter and such in it. Oh, here’s an idea: it turns out that the way of using Hilbert Spaces in describing quantum mechanics can also be used to describe classical mechanics, if you make a few changes (instead of having the position momentum canonical commutation relations, you have them commute, and introduce some other variables to have the canonical commutation relations with position and momentum respectively, and also the way observations work is changed. This ends up being, iirc, equivalent to the usual way of formulating classical time evolution of states with uncertainty (not like fundamental quantum uncertainty relation uncertainty, just like “our initial measurements are imperfect” uncertainty).) . What happens when we try to formulate general relativity in this framework? Well, I guess first we would want to formulate some simpler classical field theory in this framework. And then formulate general relativity in it. Ok, so the plan would be: 1) Formulate a classical non-relativistic field theory in this framework (called “Koopman-von Neumann classical mechanics”, and in the rest of this comment, abbreviated as KvN). 2) Take specifically a non-quantum version of some non-relativistic quantum field theory, and formulate in KvN framework. 3) compare it to the usual QFT version of the theory. 4) take the non-quantum version of some relativistic QFT, and formulate it in KvN framework. 5) compare that to the QFT theory it corresponds to. 6) formulate GR if the KvN framework 7) using the previously found relationships between the KvN formulations of classical versions of various field theories, try to find the appropriate analogy. I don’t know which steps of this plan have already been done. Maybe all of them have been done, or maybe the first step doesn’t work.
You're not wrong, really. This page itself isn't stored anywhere, just the instructions to recreate it. So when nobody is looking at it, it's not there.
![Blox Fruits Dragon Rework Update [Full Stream]](http://i.ytimg.com/vi/EqDAp8udhm0/mqdefault.jpg)
PBS Space Time reminds me how much I want to keep learning.
Lay off the Adderall bud 😂😂
I’m 50 and agree with you. This is an amazing time to be alive with how much knowledge we’re gaining in science.
I’ll be honest, pbs space time taught me that there are boundaries where meaningful learning disintegrates. If you actually start learning the technicalities, you find that goes little beyond the math….
Constantly pondering what ifs is rather pointless….
They remind me of how much I may never learn with how much there is to learn, because behind every door of new discovery we open up, there's a hallway of locked doors to try and unlock, in order to see what's behind them!
Depends on the healthcare plan
PBS is one of the reasons I decided to study physics, currently struggling with classical mechanics, but I won’t give up, the goal is a PhD in physics, thank you for keeping up curious ❤️
Edit: I have passed the module, I’m now doing a physics and pure maths double major for my final year, next update will be graduation. Thank you for all the positive messages.❤️
You got this!
Piece of advice from someone who wasn't able to make it work for me. Don't over pack your schedule. Take the time you need to actually learn and understand all the things that are relevant. All the math classes are relevant even if you don't see how it could be used in the present. Good luck!
Eyyy me too :D
I’m a 1st year in college trying to get a degree in theoretical physics. They help so much in understanding in a fun way
@@zacrintoulElon muck took 7 years to get his bachelors soooo
This show is such a gift. It strikes that perfect balance of technical details and concepts while not totally abandoning those who don't work in the field.
This show is crap. He mentioned space time as though it actually existed.
Nothing makes me happier than finding a new episode while winding down body before sleep. This channel is pure bliss. Also Matt is a fantastic narrator ❤️
You and me both🤞🏾. Whenever my body is at 1%, Im on a mission to find that ideal video to drift off to sleep. Their content is like a soothing treat 😴😴
Yeah, matt mercer always makes the conversation interesting!
who is matt mercer ? matt o dowd is the host@@rezzaprasetyosetiawan4431
Buddhist stories are better.
Space can come into existence without using a previously existing ingredient (Prathya), and also, space element (Akasa Dhathu) emerges from the 4 existing ingredients called Aharaja (foodly molecules), Cittaja (mindly actions), Wruthuja (weatherly elements), and Kammaja (reactionly entanglements) according to the Buddha's teachings. Form is emptiness, and emptiness is form. Probably, the two forms of emptiness can behave like space (free points of space) and counter space (solid points of space). Space could increase due to the unstoppable flow of the absolute time from negative time (from zero-infinity) to positive time (to infinity).
The analogy of foamy spacetime also serves to explain what I mean when I answer with "nothing" to a "what are you thinking about?" question.
A bunch of virtual thoughts and anti-thoughts, altering the geometry of my mindspace. The fluctuations are there if you look close enough, but from a broader perspective it looks perfectly level. In other words: *no thoughts; head empty*
There is a book - "Theory of Everything in Physics and the Universe"
"Foamy spacetime" aka a worse name for a concept that already existed
But a great name for a band.
Too humble. Your 'nothingness' is what most people lack and should envy. You are very good at self-observation. This very deduction of yours can be labeled as 'Hawking radiation' of wormholes. (inside your not-so-empty head) 😊
Man, the writing in these videos is INCREDIBLE. The way you explained the heisenberg uncertainty principle in combination with GR in such a easy to understand and logical way for people who dont have university level physics education is mind blowing. There's no where else on youtube where you get such easy to understand but in depth videos on such insanely complex topics :D
Yeap.
Its amazing this channel isnt super famous
@@OuroborosVengeance3+ million subsribers isnt super-famous in your book?
@@KendraAndTheLaw Blame public education being paid for by taxes on property owners.
@@kvdrr well, yeah, i might be putting the bar a bit too high
Yes that part blew my mind
Great content on a very complicated subject. Matt is a fantastic communicator. thank you PBS for supporting and producing this content.
This sounds like a bot comment
The writers are excellent at writing an easily understandable presentation, not just Matt.
People like you are the reason there's a writers strike presently taking place.
@@ACuriousSquirrelmat is writer himself too
@@LuisSierra42 Well my friend I'm not a bot, flesh and bones.
@@fredyair1 😱😱
You know you've been watching spacetime for a while when you know who Wheeler, Feynman, Thorne and Everett are and what their contributions were to physics. 6 years ago, I would have had no clue.
This guy just learned what 'learning' is
@@cryotimberthis guy just learned what "learning what "learning" is" is
@@cryotimberyour comment displeases me and i find it quite annoying and pretentious do better.
You've good memory, lucky you you have no ADHD like I do :(
That's great you learnt something from him & if learning physics makes you feel happy but, never forget the fact that Science is nothing more than the study of phenomenon/ process/ know-how which is perceived by our limited knowledge, intellect, understanding and senses like hearing and seeing ability. And Ideas/Theories are proposed by observations which are perceived by our limited senses.
So, when a Programmer elaborates the importance of Binary Numbers/ Language Code of the Computer & explains (know-how/ phenomenon/ process) how a Machine/Computer talk then it does suggests us that there is a Programmer /Designer behind a computer. And, a human body is one of the most complicated machine on Earth let alone if we talk about the Universe which is much bigger and complex than our DNA 🧬 A Unique Program/ Instruction Manual/ Code).
I was watching an older video and paused it to come to the newest video comment section because it's new. Anyways I just wanted to thank this channel. I started watching it and although it interested I didn't understand much of anything and couldn't grasp some concepts. After a year and a number of youtube videos later I really feel like I'm starting to understand this stuff alot better. I'm now able to follow along and not be completely lost. The most I took in school was grade 9 physics and it didn't interest me at the time. Now I'm 34 getting into physics, and my only regret is not learning this in school. Thank you PBS spacetime.
I want to thank the writers for their efforts in making this an easy listen and Matt for his oratory skills! It's always a pleasure to tune in and learn about this fantastic cosmos we live in. You guys and gals ROCK!!!
I think Matt is writing most of it himself, He is an astrophysicists and not only good at speaking and present it.
I've been watching SpaceTime for years and never known who's actually writing the episodes. I'd love to find out, whether it's Matt, a writing team, or some combination.
I believe Dr. Matt writes his own material, which just adds to how impressive he is, and to the series production as a whole.
This program is a farce
this show is such a great contribution to science education and humanity, you take us on the ride of modern physics without needing us to do the math
I apprentice your choice of words that convey the innate uncertainty of all scientific theories while recognizing all the work that went into our current understandings
It's just a perfect channel and I wanted to thank you for your service
I'm increasingly uncertain about the amount of beer I actually have under an alarmingly large expanse of foam. I guess only time will tell how much empty space I am left with once it settles.
Drinking beer for science
When beer creates uncertainty of position and of momentum, you're going to get wet.
I suspect you risk becoming a gas giant...
@davidb6576 and can have 2 plumes when erupting.
@@beaudweiser Brewing beer is science for thirsty people 😁
that ocean surface analogy was fantastically presented.. thank you pbs space-time team ❤
But it's just an analogy. Analogies are not evidence. Be careful.
@@KendraAndTheLaw the title beginning with "What If" makes that clear
Audio sounds more natural this time. Appreciate whatever the team has done to improve it. Great episode, too!
Yea but his voice is weird?? Can’t tell you what but he sounds different
Sounds fine, the audio was really weird from 2019-2021 @@rwood1995
@@rwood1995because the sound editing is very bad. Too many unnecessary filters. That's why Matt sounds generic and unnatural now 😢
Yes, he sounds like he has a cold
It's definitely aliens
the animators are getting better and better, that's a real treat for the viewers. thanks to the team
You’re just saying that because of the capybara
This theory explains so much and even though it hasn't been tested it has that intuitive quality of beauty that correct theories tend to have. Thank you Matt for your excellent presentation and graphic illustrations.
Its just luminiferous aether by another name
"it has that intuitive quality of beauty that correct theories tend to have" - don't let Sabine Hossenfelder hear you say that lol! 😅
Reminder episode starts with a What IF part of series that starts with What If Space And Time Are NOT Real?
Note Quantum Mechanics is extremely non intuitive to the point human brains have trouble. And I have intense trouble understanding Relativity as in how it truly works.
Plenty of beautiful incorrect theories.
@@milferdjones2573Quantum þeory becomes very intuitive once you realize it's just ðe equilibrium case of Bohmian Mechanics. Ðe latter þeory has just two ground axioms: Schrödinger's Equation and ðe Guiding Equation. Everyþing else follows from ðese two. BM can wonderfully explain ðe measurement problem wiðout invoking any mysterious, ill-defined, or non-physical concepts.
Another stellar episode gents. This one really made it click for me why an empty vacuum would have non-zero energy. Turns out it's that pesky uncertainty principle at work all along, except for geometry itself, that would never occur to me.
Big shoutout to the whole production team by the way. Matt is such a treasure to listen to, truly the David Attenborough of physics. The animations make it really easy to grasp what Matt is describing by visualizing the effects. This time in particular they were helpful to intuitively understand the effects described and looked really cool too.
It's a real privilege to be able to learn so much about the natural world, this type of knowledge was unheard of for most people until just a few years ago. Now it's accessible to the common layman like myself who have a curious itch to scratch when it comes to the underlying workings of the universe. I am not sure if you guys are aware how important the work you do is, but just know it means a lot to people like myself. So thank you for your efforts and may many more stellar PBS Spacetime episodes air on this channel.
You couldn't figure it out before? Are you dum?
Exactly:)
5:00 Be mindful that the Heisenberg Microscope makes it easy to confuse the uncertainty principle with the observer effect. One can argue in this vein to show the trade-off in uncertainties, but it makes it easy to mistake any uncertainty for a product of a measurement, rather than an intrinsic property.
Yeah, the Heisenberg Microscope makes it way too easy to conflate those. Do you know of any (relatively) easily imaginable analogies or thought experiments that help us to distinguish the two (purely epistemic uncertainty vs. Fundamentally Real metaphysical uncertainty)?
Real metaphysical physics you say?
Hmm
@@harmonicpsyche8313Yes, on this very channel there was an episode called "Breaking the Heisenberg Uncertainty Principle" that explained it beautifully.
Pumped my fist alone in my kitchen, I love PBS Space Time, it's such a treat seeing a new video pop up!
this is easily one of the most interesting and informative channels on the internet. much appreciated
Over the past 7 years or so I've probably watched about 100 hours of this channel.Anyone else ?
This particular script was just a pleasure to hear and follow! And the visualizations were especially sick and on point. Kudos to the team!
Can you put up a 10 minute repeating video of that quantum foam? It was oddly satisfying and relaxing. Bonus points if the audio is Matt reading his favorite physics paper.
Imagine sailing in a boat of size of a peanut through an ocean with waves higher than a skyscraper for 40 billion years. And then astronomers catch you and say aha, this fella must have been emitted by a helium atom from galaxy GE-5576 around a million years after the Big Bang.
Sure is wild! Add to it that light is moving at the speed of causeality so from it's point of reference basically no time at all had passed.
about two weeks ago I was watching multiple people play in a swimming pool independently and observed the rhythmic fluctuations of the water. I was imagining the people as particles and the water as space, so this analogy felt very intuitive to me. super cool!!
There was a lecture leonard susskind gave where he said that quantum entanglement appears to be the thing linking different regions of space together. Highly entangled regions are closer together and weakly entangled regions are further apart. It was a possible implication of the ER=EPR paper that draws a connection between the wormholes of GR and quantum entanglement.
As I understand it, theorists discovered that 2 entangled black holes (2 sets of entangled particles compressed to form 2 black hole) can be equivalently described using the Einstein Rosen bridges of GM and using the entanglement of QM. You can model the 2 black holes as being connected by a wormhole or as being quantum entangled and you get the same results either way. Its as if they are just two sides to the same coin. This lead to the argument that if two entangled things can connect separate regions of space via a wormhole then maybe entanglement is what connects different regions of space in general.
I dont know why, but I really intuitively like that idea. The nonlocality of entanglement seems to suggest it is possibly something more fundamental than spacetime
I just want to say that I appreciate how the titles of these videos seem innocent enough to hook viewers who might be more hesitant about clicking on more complicated sounding videos.
I like watching these videos because they always click something into place that I had a hard time understanding
I watch this because one can learn some ideas. Learning from failures and dead ends often is illuminating. I don’t watch this because I believe GR is incomplete due to its conflict with QM. It is only logical that QM is also incomplete for the same reasons. If QM wasn’t incomplete, we would understand why the strong force is short ranged, why color confinement happens, the nature of anti matter, we would prove that hawking radiation is real and so are gravitons, and of course, we would know the answer to the measurement problem, moreover, we would know definitively whether non local hidden variables are possible or not. The dogma is sad and dangerous, but it also allows room for great discoveries to be made.
Time for another dose of PBS, the only informative RUclips channel where I feel more stupid the more I watch
That just means you're learning! If you go back to earlier episodes, they'll likely actually click much quicker. Nothing wrong with feeling a bit over your head: it's what you do about it that matters.
The surest sign that a person does not understand Quantum Physics is that they think they understand Quantum Physics.
Some people understand some parts of the subject, and know how to use some tools to study it. Not even our greatest minds understand all of it. If they did, they would publish their unified theory.
Actually... thats not quite right
I'm fascinated by how some people's reaction to education about the outside world is to marinate themselves in how it makes them feel about themselves. Like, why do you need to make a value judgement? Just learn. You don't need to have already known about the things you're learning.
Astronomy magazine gave me the tools for a general understanding going into these type of vids.
Quantum scientist here, love PBS Space Time, quick correction at 4:50: The Heisenberg uncertainty principle is not equivalent to the classical observer effect, where measuring a particle’s position disturbs its momentum. The quantum uncertainty principle tells us that the more well defined a particle’s position is, the less well-defined its momentum must be, and vice versa. It’s not that we can’t accurately measure both variables at the same time; the particle literally doesn’t have fully defined values for position and momentum at the same time (depending on your interpretation of Quantum Mechanics).
This is unfortunately a common misconception, contributing to the general confusion as to how quantum and classical mechanics are different. For a clear explanation (and explicit confirmation that the two effects are not equivalent) I recommend your original video on the Uncertainty Principle!: ruclips.net/video/izqaWyZsEtY/видео.html
Ahh that graphic with Einstein and Bohr is already a classic. Superb idea whoever on your team came up with it.
The explanation of Planck length's connection to GR's nature of energy distorting spacetime, and the connection to Heisenberg's uncertainty of the energy (uncertainty is equivalent with pairs such as energy/time or position/momentum) was a huge revelation to me. First time I got a physical intuition for where the "any traditional spacetime geometry stops at Planck's length" thing comes from.
Ohh, the energy/time thing is mentioned right after.
(Maybe I should watch the video until the end before commenting.)
I wish this would've been available when I was in school. I hope the kids know how good they've got it nowadays. Had to read all that stuff in books / pay attention in class / even do some homework sometimes
Yes, mental illness for young people is at an all time high, they have it so so good
lolol right? There are definitely MUCH better learning materials than ever before, and way more accessible. That's pretty cool :)
@@stefanfyhn4668dude, that anger has to come from somewhere
mental illness has always existed, we just have names and diagnoses for them now...@@stefanfyhn4668
@@stefanfyhn4668 regardless, what OP said is definitely true. It's much easier now to have access to information
Matt, thank you! Your emphasis on spacetime "falling apart" at the Planck level helped me see a new and, I think, more quantifiable interpretation of quantum mechanics as an algebra of interacting xyzt instances created by varying-scale collections of closely interacting mass-energy parts. Each frame xyzt has a resolution, orientation, and... hmm, yes, a spin! Interesting... I wonder if some Planck foam maths might be relevant if rescaled attached to mass-energy limits? An xyzt instance algebra of multi-scale spacetimes that interact and rescale (collapse) each other, with the high-mass units tending to dominate, opens up new paths... Perhaps that's all collapse is: Joining the larger local Inertial Frame Club. Again, thanks!
Thanks PBS Space Time for the upload, Always good to see space on RUclips. 👍😀
Re the uncertainty principle--just because we can't know something, doesn't mean every extreme possibility is occurring. All the uncertainty principle says is we literally don't and can't know. Maybe virtual particles aren't real. Maybe there is zero energy at the Planck scale.
Edit: It turns out it has been experimentally confirmed that particles can spontaneously emerge from a vacuum, however, the explanation may not require virtual particles.
You talk about particles ...may I ask what do you think they are?
A particle is by deffinition a very specific localised excitation in a quantum field.
Let's study the electron . We refer to the electron as a particle with a mass of 0.51 MeV and as being an excitation in the electron field. Everthing is made up by 1,2, 3 etc electrons, but never of 1/2 electron , or 3/2 electrons. That means that particles are quanta.
Now, the punch line : When the electron field vibrate with the exact energy of 0,51 MeV or multiple of that number it will be a real particle , if not then its gonna be a virtual particle. For example: a vibration in the electron field of 0,71 Mev its the virtual particle.
This process is happening in all the 17 known Quantum fields. When it vibrates with the energy numbers that you will find in the Periodic Tabel of Elements and integer multiple of those , then a particle will appear in existance. In all other cases, we call the vibrations of this quantum fields , guess what? Virtual particles !
every each one of your videos is absolute masterwork.
I've rewatched this vid several times but the uncertainty of understanding seems inverse to uncertainty of insomnia. I love it!
Thank you for this episode! I don't think I've ever adequately understood just what the "quantum foam" of "empty" space is supposed to actually be like. This helped a ton! By the way, are there any plans currently in the works for a larger UV telescope than Hubble?
God be with you out there everybody. ✝️ :)
I watch your videos instead of the Hollywood Sci-Fi abominations. This is some quality content here and your persistence in producing it is admirable. Keep going!
I've known for a while that the Planck length is the shortest meaningful distance, but I never knew why. Finally being able to connect it to other physics concepts is like a lightbulb moment
So annoyed by that word for a long time like theoretical physicist didn’t even talk about it EVER.
What I get from this is, that the planck length, rather than implying that there is a quantisation of size, is just a limit on what we can currently resolve.
(Because of the quantised nature of the photon.)
I don’t think it’s a matter of what can *currently* be resolved; It is a real limit of what *can* be resolved due to the properties of a photon.
Absolutely amazing representation, I love how it's not made to look dreamy or magical
PBS Space Time reminds me how much I want to keep learning.. PBS Space Time reminds me how much I want to keep learning..
PBS Spacetime is like Bill Nye for adults.
My love for this channel is unmatched. With all the grand questions being asked, feeling insignificant and unable to ever answer many of our big mysteries - this makes me feel connected to whatever this universe is. So grateful for this information ❤
10:22 this is the first time I’ve heard that they can have negative mass. Everyone always says that they’re just “antiparticles,” which implies that their charge is opposite, when it is actually their energy.
Same! Even antimatter has positive mass, virtual reality rocks.
I could be wrong but I remember hearing somewhere that virtual particles are not bound by he speed of light/causality.
So, they move faster than light.
Back on topic now; virtual particles have negative mass? Someone, quick, call Miguel Alvubierre! Tell him we found his exotic particle! The Alcubierre Drive just became one dyrp closer.
@@WolframHeart-xp2px See spacetime on virtual particles. They are not real like real particles and thus they don't have to comply with lots of parts of physics. They are approximations of what is going on not what is actually going on that we do not have clear idea of. Virtual particles can't be extracted from anything and isolated so can't use them to make the Drive work.
@@milferdjones2573
But, then what about the Casimir Effect?
Isn't it related to this topic?
Not that I necessarily believe we could extract virtual particles, but that at least a portion of physics suggest they are there is something nice to have. But hey maybe something will come from it one day, right?
The Casimir effect is a result of a more complex phenomena that can be more easily calculated using virtual particles. The virtual particles themselves are a nice mathematical construct, but they represent something real.
In the same way we can treat alpha radioactive decay as a pre-exisitng particle inside the nucleus randomly tunneling out after bouncing around a bunch of times. The particle doesn't exist like that, nuclei aren't hollow shells filled with marbles, but the construct DOES represent something and radioactive decay most certainly happens.
One of my favourite things about science at this scale is that you can have a situation where you use technology to analyze data of stars billions of light years away to help find evidence for a theory about what time and space looks like on the smallest scale. Just wild, in the best way, but still.... Wild ❤❤❤
Could the theoretical small wormholes opening at the plank scale explain quantum tunnelling subatomic particles? Thanks as always Matt and the whole PBS team!
As a pedestrian mechanical engineering graduate student, I recognize a lot of descriptive similarities to the work I’ve done in turbulence research. Thank you for the video. I might have to watch it a few more times though!
Deep down we all know that our collective missing socks are somehow responsible for many of the phenomena we see.
That was a groundbreaking explanation. Not sure if I watched same explanation before, but linking uncertainty from Relativity and uncertainty from Principle of Heizenberg to the square of Plank lenghth was really amazing!
Never clicked a video faster. Love the content you make
[5:00] This is the first time I have understood the reason for the Heisenberg Uncertainty Principle, thanks!
That idea has a name. It's called "Heisenberg microscope" and it's 100% false. The uncertainty that the Heisenberg uncertainty relation describes is NOT the uncertainty of an individual measurement. It's rather a mathematical phenomenon of linear operators over linear function spaces. You will encounter it every time you do a Fourier transform, even if that Fourier transform is taken over completely classical data that has no physical uncertainty whatsoever. You can find it discussed in textbooks on acoustics, geophysics, signal processing, it's part of your Wifi router's collection of algorithms and to a mathematician it's a trivial lemma in introductions to functional analysis. Why Heisenberg felt the need to build a fake physical model for it is unknown. He should have known better.
@@schmetterling4477 Okay, now I am back to not understanding the Heisenberg Uncertainty Principle.
How would we distinguish between space-time foam and the effect of the intergalactic medium on photons travelling those vast distances?
WHIM effects should be rarer but larger in magnitude and involve outright scattering -deflection of light in a totally random direction. In a sense the charged particles of the WHIM are like rogue waves on a choppy sea, following a separate distribution, one that can overturn even large boats. And we see such effects, as well as even more obvious effects from intervening clouds of gas. (The latter giving us the 'Lyman alpha forest' in spectra.)
I like this channel because there's always something ancillary yet relevant to the subject that ends up leading me down a rabbit hole. For instance the Planck length. It leaves me wondering whether the length exists because that's the minimum size of space something can occupy or if its just the minimum size we can detect. Then I wonder if we know our measuring photon is X wavelength, why not calculate and subtract whatever change it has on the gravitational effects of the space we want to measure. And I haven't even gotten to the main subject! Dang you PBS Space Time for these rabbit holes!
I seem to remember that this velocity/position measurement explanation was a misleading misinterpretation of the Heisenberg uncertainty principle. That the HUP has nothing to do with measurement and everything to do with the actual wave function, so that constraining one variable actually spreads out the possibilities that the other variable can collapse into. Was it not on this channel where I learned that?
Edit: Yes, the PBS Space Time episode explaining it was called "Breaking the Heisenberg Uncertainty Principle".
In an earlier episode (can't remember which) it was discussed the black hole might not be able to evaporate completely. They might just sit at the plank limit. Wouldn't the idea of cosmic foam prove that not to be the case. Because if black holes were always popping up, the universe would just be filled with tiny black holes. Am I misremembering the episode or is something else going on?
Very unsettling to think there might be tiny black holes in or near my body
Those would be two very different types of plank-scale black holes. The ones discussed here are in some sense "virtual" black holes, their mass-energy comes from the uncertainty of space. "Real" black holes that evaporate down to the planck scale would still have one planck mass of real mass-energy, that may or may not be able to evaporate, and if it can't evaporate it cannot return to nothingness like the virtual black holes can because of conservation laws.
Matt you are the best. i love being able to play sections over and over until my mind stop wondering off on some previous explanation, and i get the next one.
What i have been wondering about the quantum foam, is can momentum be imparted upon it? Does something near the speed of light have a wake? Does a rapidly spinning massive object deform the quantum foam?
Yes, it should. This is a relation to 'vacuum polarization' where the charge of a particle alters the vacuum. It would be a very weak effect and depend on whether we treat gravity as a particle-mediated field or a warping of spacetime. The latter, on larger scales, gives us 'frame dragging' and gravitational waves.
5:40 my brain is melting.
perhaps i didnt understand this as well as i did
but i did enjoy your analogy of the boat on an ocean
is this the most precise way to say it however?
like is this the difference between active and passive voice?
because the photon never "gains" energy
simply pops in and out of existence, as mass is converted into energy, like photon
I like how he brought it back to the flat space like the ocean.
Great episode!! "The vacuum is alive keeping the divide between motion and stillness." Hiesenberg~ This quote of his is a beautiful explanation for the interaction between space-time, the vacuum, and the nothing.😊
luminiferous aether in another name...
It always blows me away how most of what we know of reality is just things we deducted from observing objects that are imopsibly far away from us
Most things are impossibly far away from us. Like, all of the universe except Earth. Thats most of "reality".
That's bc these "geniuses" know nothing
Nice misinformation. “Know nothing” lol.
@@mblake0420jealous much 🤦♂️
@@mblake0420easy to say when you know even less
At the beggining, you mentioned 2 possible "fixing" of Gravity & Quantum Loopholes vs String theory, but what about Verlinde's gravity or entropy gravity theory ?
Could you make a episode on that ?
That water/foam analogy reminded me of a line from the movie Ponyo,
"If it fails she'll turn to foam"
"But that's where we all came from."
Turns out Hyaio Miazacy is a bigger genius then everyone thought.
Analogies are not evidence. But they can be useful for explaning relationships. Be careful.
I'm enchanted by how badly you've spelled Hyow Meeazarkee
Lol the "quantum foam" what a goofy name. It's luminiferous aether re skinned
I'm more excited by a new episode of space time than any tv show.
Isn't Wheeler the "one electron universe" guy, too?
Very nice analogy used by Wheeler to get a picture , what is happening on small scales, an ocean of possibilities !
You know you’ve been watching/listening for so long when you can instantly tell that Matt has a wicked cold he’s pushing through 😂
Still kills it though!
The sound editing was terrible last several videos
This isn't a cold. It's the Adobe Podcast AI. It re-synthesizes the audio and makes everything sound higher pitched.
@@mynameisChesto I can’t tell if you’re joking or not 😂
@@LaMagnatron It's not a joke
@@mynameisChesto but the image is real? His nose was red AF
Fantastic work on this video once again.
If there are tiny wormholes, could that be why particle positions are random? Are they going through these wormholes?
@@retiredbore378 I thought subatomic particles were infinitely small. ಠ_ಠ
The randomness of particle positions is a fundamental property of nature that is not fully understood as of today unfortunately :(
@@billcosby12344321 but what if this is why it's random? They're just normal particles that are going through randomly generated wormholes.
@@noahwilliams8996Good point.
Well, how about composite particles? They have a size (sorta. There’s uncertainty on the size. But whatever.)
If the position momentum uncertainty relation is due to particles (having some amplitude of) going through wormholes, would we see the same position momentum relations for composite particles? Like, if the composite particles would be too big to go through.
Hm, well, if the position momentum relations for the elementary particles obey the relations,
that normally gives rise to the relations for the composite particles I think?
Suppose composite particle comprised of two elementary particles with the same mass. Position operator of composite particle should be the average of the two position operators, momentum operator of composite should just be the sum of the two momentum operators.
Taking the commutator...
Yeah, that gives the canonical commutation relation for the composite particle.
So, if the wormholes can explain the canonical commutation relations for the individual particles, then I guess it would explain for the composite ones as well...
But...
Does it make sense for it to explain the commutation relations for the elementary particles?
Seems like it could contribute to uncertainty in position and I guess also momentum,
but... could it explain the commutation relations?
For that...
Hm.
Well, it doesn’t seem like it should in an instantaneous way at least?
Like, if it were the case that “without these wormholes and such, position and momentum would commute”, then...
well, then at any moment they would commute.
But, if say, we let the position and momentum operators evolve over time (using the Heisenberg picture rather than the Schrödinger picture)
then...
perhaps the evolved forms of it could tend to have approximately the canonical commutation relation? This seems a bit far-fetched to me, but also interesting.
It would be interesting to see if one could describe a system where position and momentum operators by default commute, but where after evolving for a long time under the time evolution, tend to approximately satisfy the...
Oh wait.
If \tau_t(A) is the result of evolving an operator A for time t,
well, this should be an automorphism,
so [\tau_t(x),\tau_t(p)] = \tau_t([x,p])
So, that can’t work.
Not to say there couldn’t be any other way the CCR relation could potentially arise from said wormholes and such,
just, I can’t think of any.
I believe they exist on an even smaller scale than those particles.
The water example would be better illustrated with underwater example in the end. We are underwater and don't see waves, it looks the same everywhere. The waves are only the "edge of the universe".
how can it be so many comments already? hahah
This videos made me a science fan, love them
.
Some of the comments went back in time due to quantum uncertainty.
5:04 thank you matt for letting me help you correct it
Would a better analogy for spacetime foam be a submarine passing through the water, either deep, shallow or surface?
In deep water, the travel would be smooth, but still all encompassing- whereas the plane analogy creates a visualisation that implies a separation of the observer from the subject - which is impossible from our limited perspective.
Just a thought - love the videos!
Why do we have to deal with trolls in the comments of such an excellent video?
Great channel. I started learning physics again last year. It is great to have such a channel. ❤❤❤❤❤
If you place an object into an environment with specific conditions, that object will either change to accommodate the environment or the environment will change to the accommodate the object. Same fundamentals as entropy and the three body problem.
A telescope to test this would be amazing. Is there one in the works?
They're building one on Uranus.
Just so love this channel.
It doesn’t talk down to you.
Everyone can get something from it.
Inspirational 🎉❤
Thank you 😊
First impressions: thanks to the video editors for not compressing/speeding up the audio on this video. The last few episodes were really annoying.
*Edit: fascinating content, made all the more engaging thanks to Matt not sounding like a chipmunk.
hadn't even noticed lol
@@kori228 Good for you, dude! I for one (and I'm not alone judging by the comments on recent videos) was getting distracted by the poor audio quality.
This is the best science-themed video I've ever seen. Thanks a lot for your passion to show us these amazing things!
"Space isn't empty. It contains the whole universe." - Alan Watts
And consciousness contains that.
This is an interesting idea and one that seems to resonate with many people. It's relatively simple concept. The closer you look at something to more fine details you notice. This can change things a lot. Most of the issue is we are looking at stuff from very far away compared to the plank scale and can't see the details. If we can find ways to look at this closer then we may uncover things like this foam. It is also suspected that light may not travel at C in a vacuum I heard lately. But that the difference is so small we can't see it. Very interesting concepts.
Thank you, Matt, for once again leaving me enamored with the wild possibilities of science. You continue to inspire me to keep learning and pushing for that next piece of knowledge. Another fabulous video and I do very much look forward to the next!
This is a good description of something that is immensely complicated
Actually spacetime on a small scale is a bunch of cool people who work together to make awesome RUclips videos.
Excellent presentation, excellent learning experience.
If something can not be measured, does it still exist? If a star continues to collapse until it reaches a plank length, what happens then? Does it stop collapsing?
Unknown. Our inability to measure smaller does not mean something can't be smaller.
Atoms existed before our ability to measure them #justsaying. A star would not collapse to planck length, the constiuent parts are too big. This is why collapse triggers massive outbursts of energetic particles
@@punchkitten874 How do you know this? Is there anything that prevents subatomic particles from being compressed infinitely?
@@michaelcliffordphotos dude you need Dr. Becky
@@punchkitten874 I watch her too.
The animations in this episode were super helpful!
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Correct 👍
👏👏👏
I don't see comments. Just a screen?
Brilliant 🤡
I didn't know if it was empty or not before I opened the comment box 😉
The field equations are wrong at 6:42 - the numerator of the coupling constant should read 8πG and not 8π/G.
"More work is needed" Also as a biologist, this is the ultimate conclusion of so many experiments. The closer you look, the more complicated things get, and the more you have to look 😁
science will pretty much always be this way, there's always more to discover!
"Science knows it doesn't know everything. If it did, it'd stop." -Dara O'Brien.
Why is it always assumed that it is GR and not Quantum Theory that needs "fixing" to make them work together?
GR has more discrepancies in what we observe than quantum theory. That's why we see things like dark matter, MOND, the issues with galactic rotation speeds, and observations of galaxies that don't seem to fit any of the models. Quantum theory has its own issues like the vacuum catastrophe, but GR seems more incomplete based on what we observe.
@@Garresh1 Do you think the reason that this feels backwards to most people is that we (mostly) observe GR on our scale (humany sized things) as opposed to Quantum Theory (mostly Planky sized things), and this throws our intuition off of which one we're measuring more often, most accurately, or with the fewest discrepencies?
@@scottglajch1555 I don't think that assertion is correct, actually. The first confirmed observation of GR occurred during a solar eclipse when the position of stars was slightly shifted due to the light being curved. And within our solar system the only thing GR has any effect on is the orbit of mercury. Nowadays we have to account for GR with things like GPS due to the insanely precise timings. On human scales everything can be explained with newtonian gravity.
Quantum mechanics on the other hand is something we deal with regularly even in our day to day lives, at least with our technology. Quantum effects *massively* affect things like CPU manufacturing and place limitations on cpu speeds due errors from quantum tunneling. Anything involving manufacturing on microscopic scales has to account for quantum effects.
So while we have mountains of evidence for both, I'd argue quantum effects have a larger effect on our day to day lives.
@@Garresh1 Thanks. That make more sense than what I normally hear which always comes down to "We know that there is something wrong with GR because it does not play nice with Quantum theory." My suspicion is that most of this is due to the fact that GR is deterministic based on what is measurable while quantum is build on the probabilistic description of the immeasurable. Given that framework it is no wonder that they do not fit together.
I wonder if this distinction really exists?
Like, of course both would be different. GR doesn’t have superpositions of states or uncertainty relations, and QFT doesn’t have a spacetime that changes based on the matter and such in it.
Oh, here’s an idea: it turns out that the way of using Hilbert Spaces in describing quantum mechanics can also be used to describe classical mechanics, if you make a few changes (instead of having the position momentum canonical commutation relations, you have them commute, and introduce some other variables to have the canonical commutation relations with position and momentum respectively, and also the way observations work is changed. This ends up being, iirc, equivalent to the usual way of formulating classical time evolution of states with uncertainty (not like fundamental quantum uncertainty relation uncertainty, just like “our initial measurements are imperfect” uncertainty).) .
What happens when we try to formulate general relativity in this framework?
Well, I guess first we would want to formulate some simpler classical field theory in this framework. And then formulate general relativity in it.
Ok, so the plan would be:
1) Formulate a classical non-relativistic field theory in this framework (called “Koopman-von Neumann classical mechanics”, and in the rest of this comment, abbreviated as KvN).
2) Take specifically a non-quantum version of some non-relativistic quantum field theory, and formulate in KvN framework.
3) compare it to the usual QFT version of the theory.
4) take the non-quantum version of some relativistic QFT, and formulate it in KvN framework.
5) compare that to the QFT theory it corresponds to.
6) formulate GR if the KvN framework
7) using the previously found relationships between the KvN formulations of classical versions of various field theories, try to find the appropriate analogy.
I don’t know which steps of this plan have already been done. Maybe all of them have been done, or maybe the first step doesn’t work.
I killed my astronomy class test curve by acing the test and then on the back explaining how the universe is a fishbowl and not a vacuum.
The comment section only exists when Observed.
You're not wrong, really. This page itself isn't stored anywhere, just the instructions to recreate it. So when nobody is looking at it, it's not there.
Another fantastic episode. Carl Sagan would be proud.
Obviously, as some of us have been pointing out for ages. What we call "space" is not an empty void, but a fullness brimming with immense energy.
I have to congratulate u on the excellently presented content as i congratulate myself for understanding most of it.
I IMMEDIATELY clicked on this, I missed you guys ❤️❤️❤️
saaame