Loving the fact you get straight into the equations....and give really clear narrative about how they work and what they mean. I'm not a physicist, just have an interest. So many lectures aimed at folk like me avoid the equations; wrongly in my view. Keep it up!!!
Agreed. The derivations make it very clear what the implications are and don't require anything more complex than some calculus (and a lot of algebra) to follow. Of course it's far easier to see it explained than do it yourself!
Sure "the universe should have torn itself apart in a minute fraction of a second" sounds bad but I maintain that "ovens should produce limitless energy and radiation" is still the worse prediction.
But it's the only explanation where I can still absolve myself of any blame when I burn something in my oven. So I'll stick with that one thank you very much.
@@gorantev If we don't know enough to know exactly where we are wrong and why, it is clear as night and day we can't and shouldn't say we know "matter" is exactly 5% of the universe, "dark matter" is exactly 25% of the universe, and "dark energy" exactly 70% of the universe, etc., etc. THAT is just idiocy committed by the most brilliant, most educated folks in civilization... similar to what Aristotle and countless others had done in previous generations (the brightest in society coming up with some of the most stupid "explanations" for how reality and the cosmos work, here on earth and "out there" in the far distance). For me, unless and until the contrasting explanations by Quantum Mechanics and General Relativity are brought to a seamless whole, like a perfectly fitted puzzle, things like (the "mysterious") "dark matter" and (the "even more mysterious") "dark energy" as well as "Inflation" (or "hyper-inflation," the Allen Guth imaginary energy) are just Planet Vulcan, Aether, Crystalline Sphere assertions, randomly & clever reverse engineering mathematical contraptions conjured up and invoked to make "theories" look plausible. It's not real science when X or Y or Z "must" have happened. Any time the word "MUST" is used, it's nothing more than Bronze Age religious fairy tale doctrines and beliefs...
Quite quite true!! For the mathematically respectful but not accomplished, this has been like the experience of the kid who's been taught a half year of cello but never heard any music but blue grass gospel in church, who then gets seated before a professional orchestra performing Brahms. Impossible to comprehend but not, in awe, profoundly to appreciate.
Pretty much equivalent to about a dozen+ hours of Lenny Susskind's/Stanford lectures(which are superb in their own right imo) but amazingly condensed to well under an hour. A priceless EDU Gem !
As someone starting a physics degree soon, I just wanted to say that you are an incredible content creator. Your work is inspiring and clear, keep up the amazing effort!
Brilliant job! I was really disappointed when the video ended after only 49 minutes. I could have listened to you for another couple of hours, at least.
Thank you so much. This is incredible content. Your technical explanations are at a perfect level for a lot of us who enjoy deeper dives into physics. I hope your channel grows.
I wish I had this video when I was in the middle of my cosmology module at university... I've always been bad at seeing the 'whole picture' as I'm learning and studying for an exam, but when I revisit summaries later on, it all fits together nicely. Your videos are excellent.
And yet he is not even questioning the theory of expansion, and is quite happy to believe in theories of mysterious energy, a rather conservative mind.
@@ps200306 It depends if your measurements are correct (they're not) and also depends how far you can see. Around the Laniakea Supercluster space appears to be contracting. Mathematical predictions of expansion do not match observations.
@@digbysirchickentf2315 , the Laniakea Supercluster is not gravitationally bound, therefore not contracting. Of course there are deviations from the Hubble flow on the scale of superclusters and below -- that's what you would expect.
New sub: Back in the sixties when I attended high school, I was drawn to read Scientific American in spite of the fact that I comprehended very little of the content. In the same way-as a layperson-I am enchanted by the production values and teaching methods of this video.👍👍👍👍👍
Aaaaaahhh… I get it!- “Dark Energy= Pi squared times energy mass velocity derivative factor over r factor multiplied by divided gravity squared plus Hawkings wheelchair minus Einstein’s whiskers” -thanks for clearing that up for a layman like myself!
I love learning stuff by listening to stuff I don't really understand like that in the background while doing chores. I don't understand most of it, but slowly I start to, or I will connect something from one thing to another thing and it will start to make sense. I now know a little bit about basically everything, which is pretty useful.
Me, reading your comment from two hours ago: Huh? it's only ten minutes to eleven. *looks at symbols in your name*: oh, yeah, that explains it. I hope you have slept well, when you read this. Have a nice day!
Same here. 3AM. Just about to put phone down & sleep...oh look here's an interesting news story about the EPA restoring scientific integrity post-Trump...article refers to Sharpie Gate...haha yea I remember that, let's watch a quick funny UA-cam video to recall what that was all about...hahaha...oh look, there's a new video from Physics Explained about the Vacuum Catastrophe. Fascinating! ...damn now it's 5AM.
You just explain these things in a very intriguing and understandable way. The usage of the equations alongside your explanation helps to better understand how one comes up with these assumptions about the universe.
This is one of the most interesting channels on UA-cam; you do SO MUCH better with physics than many other channels. I do hope this channel starts posting more videos!
Amazing, as always. Thanks for taking the considerable time to cogently summarize and relate these concepts - I always learn something from your videos.
The best physics channel I know of. Frankly, it is the first time I hear clear definitions and explanations of most fundamental concepts of modern physics, up to their limits so to speak...But to me a scale factor of 10^120 in the discrepancy of calculated and predicted values is a clear sign there is a fundamental mismatch lying at the root, and a new Einstein is needed to create a new framework to overcome it...
This is one of my favorites videos on UA-cam, so well explained and simplified, and enables you to visualize what is going on inside of the equations... You can actually see the output and you can see the transformation from concept to concrete reality.
Currently completing research for an essay regarding the cosmological constant. Your explanation of the cosmological constant problem is by some distance the best I've seen. Thanks so much and keep it up!
Your explanations are amazing. I do have to watch several times to start to get it most of the time. Can't wait to hear the ones you have planned. Who are some of your favorite physicists, alive and dead?
The clarity here is astonishing. Blown away that you can make such complicated topics so easy to understand. First time subbing after watching just one video.
Being a physics noob I have several questions after watching this video: 1) Plank's length and time simply denote the limit of our ability to meaningfully measure something. They are not some fundamental constants so why are they used as such? 2) By dividing by acceleration and its derivative we automatically assume that the acceleration isn't zero and changes with time. If it's not true then doesn't the whole thing fall apart? 3) Using the fluid equation for the whole Universe seems like a stretch. Can we really know that the Universe doesn't lose or gain energy as it changes in size? 4) We know that time flow varies. Around the supermassive black holes, which amount to a significant part of the observable mass, time almost slows down to a halt. and so do all the processes. Knowing this how can time derivatives be simply applied to the whole Universe without being inspected more thoroughly? Can someone please explain?
Also being a physics noob i can't answer these with definite certainty 1. I think its because they are constants, the Planck length isn't going to change unless something fundamental with Newton's law of gravitation or the electromagnetic force changes. The Planck time isn't going to change unless the Planck length or the speed of light change, so I think because these numbers are already based on constants and equations that we know shouldn't change that we use them as constants. 2. Its because we've observed that the universe is accelerating and at an increasing rate, although I'm not sure how this would be justified before these discoveries were made. 3. It's due to the conservation of energy that we observe everywhere, so we assume (and probably have evidence I'm unaware of) that it applies to the universe as a whole. 4. I think that's due to using the cosmological principle to say that the universe is homogeneous and isotropic, so we kind of just ignore the regions of space that are particularly different like black holes.
I am in no way a professional so I might state some mistaken points but I will try to ellaborate on Spaghett's answers: 1)Planck units (natural units) are derived using gravitational constant, speed of light and planck constant: they are basically as fundamental as these things get. The reason why they were used there is because the fluctuations should constrained by the uncertainty principle, that is have a maximum value. Planck scale makes a logical cutoff. It is true that you can get Planck units derived slightly differently and those then are different from the standard size by a small coefficient, like 2pi or 4pi, but that doesn't matter too much in this case. 2) this actually shows that the universe CANNOT be static which was goal of Friedman in studying this equation. Remember, before 60s most people thought that the universe is static and this was one of the biggest blows to that idea.
You are unreally good at explaining this stuff. In the stuff I already understand as a total STEM nerd of 43 years, you basically nail the simplest explanation I've learnt or discovered, every single time, or you teach me somewhat more. This is a rare treat. Please continue. I'll correct, of course, if there's a reason, as the scientific and didactic process lies. But for now there hasn't been a *single* instance where I could intervene. Usually mind kind of polymath *would* intervene, but you're just too good and methodical. You cover all the bases. And you're TIGHT AS FUCK! The conciseness and preciseness of your presentation well out-shines anything I've ever seen, online, or off.
@Physics Explained Your videos are a real treasure for youtube. Honestly, you should be given an award for the best physics video content creation in youtube. You breathtaking high quality presentation in your videos and unambiguous in depth and detail formal explanations and physical interpretation given, is leaving really no room for misunderstanding and is an amazing achievement. Be sure your videos are not only educational but are being used also as a review material by scholars and academics. People watching your videos not only appreciate more physics but also mathematics and how these two are entangled together the one pushing forward the other and controlled by logic. Really, best physics scholar literature content in long memory currently on UA-cam or any other public electronic media. You have risen the bar to a much higher new level . Bravo!
The single most mind blowing and important presentation I’ve seen in some time. How inspiring, not to attempt to solve the problem, of course! One might try to calculate the size of brain you might need to attempt it, but just thinking about these equations is a trip. I suspect Ill be referring to this video for years to come. Many thanks!
I'll be really sincere here and say that I didn't know what dark energy is and was too lazy to search for some boring explanation, and you, sir, made me understand what dark energy and dark matter is without being boring, and for that I must say thank you very much!
Watched this on recommendation of one of my profs after explaining that fascination with the vacuum catastrophe was a major reason I was studying physics. Good recommendation prof! Particularly fascinated by the observed/classical/quantum relationship for lambda values. It's got me thinking, 'how does one go about predicting a value for lambda-classical from first principles?' It's a good job I'm well aware (and only a tiny bit scared) that there is no bottom to the question well :). Nice work PE. Easily the most rigorous, compressed coverage I've yet sampled on YT.
For any fans of SixtySymbols, you may like to know that Ed Copeland refers to the Friedmann equation as the "Cool Dude" equation in his lectures and notes. You have to love him
To perhaps clarify - the smaller the vibration (wavelength) the higher the energy. Wavelength and frequency being inverse to one another. E=hf. High frequency = high energy (i.e. gamma versus microwave) QM uses the shortest wavelength. Why I don't know. GR is using the longest wavelength. The vacuum of space. This is like comparing the two different sides of the MTS equation. A long long wavelength (small frequency) exists at the Dark Energy side (S side of MTS) (10 to the minus 29 g/cm3) while the shortest wavelength (Planck & 5.16 to the 93rd g/cm3) (high frequency) exists as the extreme density of a black hole (M side of the MTS equation) . Remember The MTS equation is from 0 mph to "c" in the MTS direction. In the STM direction, we go from "c" to 0mph. And with Lorentz transformations along the way. [As a side note I recall I believe out of Chicago two scientists saying that as things were brought an Bose-Einstein condensate, they approached a black hole, well, this appears evident in the MTS equation as the M (black hole) side of the equation is one of no motion. I believe I left a nervous and blathering phone message to one of them some ten or so years ago. ] What I have just realized now is that there are some 10 to the order of 120 magnitudes between the M and S side of the MTS equation. In your vacuum catastrophe you are comparing a short wavelength (high mass-high frequency ) QM environment to a long wavelength (low mass - high space-low frequency) GR environment. Why? The zero point energy of QM has nothing to do with the vacuum of space. You are mixing apples and peanuts.
An incredible channel. Mind blowing stuff. Thank-you for presenting it so well. It would be amazing if and when this problem is resolved. Hopefully in my lifetime.
Very few channels provide mathematical concepts related to fundamental problems in physics as you did , I also have made few lecture videos based on equations on UA-cam , but yours are very good. Keep doing this good work as it helps people who are interested in physics.
I have always been taught that, when your model makes an prediction that turns out false (particularly if it is wildly false), then your first order of business (after checking your math over) is to go back through the various assumptions you made in your model, both stated and unstated, to determine where something we take as obvious or reasonable might in fact not be so. Since the calculated value of the quantum vacuum energy depended on certain assumptions about using the Planck Time as a 'cutoff' for frequencies that could contribute to it, that seems like one plausible place we could have made an incorrect assumption. What 'cutoff' would we have to assume in order to match the observed energy density? What would that revised cutoff imply in a physical sense, and how might we justify or verify that?
Yes, it seems that the smallest imaginable time produces an excessively large energy density, so that such small fluctuations are nonexistent, for some reason.
First off, I accept your challenge. Second, fantastic and very well done presentation on a very complex topic. A very clear approach; obviously, someone without basic physics and some calculus would not be able to follow all the arguments but certainly the general approach. As you have shown the issue becomes a problem due to the uncertainty principle when applied to the vacuum energy. There, I feel, lies both the issue and solution. I am certainly interested in solving this problem and do feel it can be done. Obviously, any solution has to use and agree with existing physics but additional extensions must be incorporated to allow a viable solution. This I do believe is possible and some aspects that I have worked out both have experimental proof (for the assumptions) and follow current physics. Time will tell (and calculation) if my approach is valid. Your youtube topic has really help me with this problem - thank you
Up date: I've actually made some real progress in addressing these and other aspects of gravitation theory, as well (like what space curvature really is) - and my basic idea as extended to gravity does agree with experimental data and is falsifiable; it solves these and other issues but I am still a long way off but aspects are falling into place
I love your cadence and your ability to take such a complex process and explain it in mathematical terms as well as in in laymen terms and make it totally understandable.
I agree. This 4D unified, quantised subspace matter-energy field model provides a few possibilities. Exploding neutrino crystals... locally shrunk/expanded subspace cell width/gap... huge hole blown in the subspace matter-energy field... Black hole universes in black hole universe... -- Bottom-up Thought Experiment... Constraints: As few base forces and particles as possible to form a coherent, integrated 4D multi/universe model -- Subspace Charge Field: +ve charge cells (ball, quanta, +1) held together by free-flowing -ve charge. Matter-energy field conserves momentum -- Matter-Energy: Matter is focused energy.. Energy is mobile matter.. Momentum conserves velocity.. Force changes velocity and/or direction -- Positron/Up Quark/Graviton (p+): Free, out of place cell warps the field, radiating AC field cell vibration 'blip' spheres at C + 6 DC spin loops -- Electron/Down Quark (e-): Hole left behind warps the field, radiating AC field cell vibration 'blip' spheres of opposite phase at C + 6 DC spin loops -- Noton/Dark Matter (n+-): Exactly opposite phase close p+ and e- annihilate (ie. entangled pair created together (e_p) ), else a noton forms -- Nucleons: Proton: P=pep.. Neutron: N=P_e=pep_e.. Beta-: N-e>>P+e.. Beta+: P+e_p>>N+p.. Alpha: A=PNPN=PeP_PeP=(pep_e_pep)_(pep_e_pep) -- Heavier Fermions: Larger holes and chunks of subspace field rapidly disintegrate to p+s, e-s, n+-s and/or annihilate to regular = empty field -- Electrostatic Force: Recoiling blip spheres propagate. Opposite direction + and - blips form a vibrating AC bond, same sign=phase repel -- Instant-Off Long Force: AC (longitudinally blipping) subspace 'flux tube' as thin as 1 cell wide. Each cell and its -ve charge move in contrary motion -- Spin: e-s and p+s pull in the 12 surrounding cells, or -ve charge that pulls cells, that then bounce out, stabilising as a torus of 6 in/out (N/S) DC loops -- Strong Force: Spin loops merge and form flowing DC circuits between e-s and p+s -- Mass: Sum of the lengths of all strong force bonds + near electric field. Notons have compact strong force bonds, Protons' are long as 2 p+s repel -- Magnetism: Some spin-aligned atoms' p+s and e-s' strong bonds join in a shorter straight path. Energy conservation results in external force circuits -- Weak Force: Geometric structural charge balance instability. Possibly noton hits statistically tipping the balance -- Photon: Charged particles moving up and down (transmitter, atomic electron) form a radiating transverse wave blip pattern -- Double Slit: Laser light / particle centre's preceding, extended subspace distortion diffracts, interferes, forming wave guides observation destroys -- Dark Gravity: p+ traps 1 quantum of -ve charge so void cell size/gap grows (and matter's shrinks?) forming a macro -ve charge gradient -- Bang Expansion: Loss of -ve charge to the multiverse?.. Bang ejector velocity petered out, magnified in time by outward momentum conservation -- Gravity Wave: Longitudinal wave where the entire field in a large region is effected in unison for a duration -- Big Ping: A dark crystal universe collisions' intense gravity wave forms e- & p+ pairs inwardly at C that annihilate or form notons, Protons, Neutrons -- Big Bang: Ping wave collides centrally? Field blast forms matter + a large hole (then Big/Dark Refill)? Fast -ve charge loss? Noton crystal exploded? -- Black Hole: Absorbs matter and energy. Noton crystal (with a core returning to empty field)? Large hole in the field traps anything entering? -- Frame Dragging: Entire sphere of subspace cells rotating around a point in unison -- Time: Cell to cell blips take a constant time. Gravity shrinks cells so light slows but locally measures C as circuits lengthen in space & time, adding mass -- Makes more sense than making up bosons to carry force and mass, quarks that don't solve the anti-matter and dark matter problem, anti-neutrinos, loads of fundamental fields, extra spatial and temporal dimensions etc, that ultimately don't tie relativity and quantum mechanics together properly or well... They should at least be honest and call their 'spatial dimensions' geometric/field dimensions or something.. Magic Space is not my cup of tea.
If space is infinite then any finite volume occupies an infinitely small volume, relatively speaking, even though it does have absolute size.. Even though our universe has expanded, if it is finite in size in an infinite space it still occupies a relatively infinitely small volume... A problem with maths or a feature of reality? I like a finite universal field occupying a finite amount of Real Space that is infinite and propertyless.. My 4D EM Field is all that is needed to explain a coherent universe.
I am horrible at math and when you got into numbers i got a bit (a lot) lost, but at least the colourfull letters and numbers + the calm voice were pretty epic
Loved the math lesson. One or two commentators raised an excellent point: what can be contained and not what is measured. We occupy a timeframe (channel) which can't see the others. We can only infer those other versions do exist using the math. Compact these and it fits the predicted value. Like your mobile phone ignoring those other numbers being dialled, our universe does the same.
This is great! As a non-physicist interested in this stuff, I've heard the massive discrepancy between the energy density prediction & observation mentioned many times, but getting an explanation as to why there's such a massive disagreement is much harder to come by. The string theory anthropic explanation seems very unconvincing. How do we even know those 10^500 other universes really exist in the first place? You may as well say God is watching the quantum pot and making sure it never boils. Surely with that many universes to choose from, in at least one of them God would exist too?
@Gerard Moloney I'm speaking only from the point of quantum physics that the life is the best self improving and self replicating machine. One that you need a decade of intense study to just realise how vast and complex it is and how much more is to discover. The metaphysical context is not needed here. Especially that I didn't declare that the life is ruled by randomness and started spontaneously.
@Gerard Moloney Thanks, but I've read the Bible. In fact I was raised in a good Evangelical household and my Dad was a pastor for a time. The obsession with sin, the hostility towards the sciences, the bigotry and divisiveness did me a lot of damage and really held me back while I dealt with the emotional fallout. In fact I consider Christian indoctrination a form of child abuse. In any case, definitely not for me!
Beautiful graphics and crystal clear explanations. I’m not a physicist but I actually feel that I understand a little more about the magnitude of the problems facing cosmologists now. Thanks.
First rate job of explanation, a real joy to sit back and watch, with pausing and catching up with my thinking. Also, I appreciate the use of yellow, blue, and white colors in the plots and equations, and at least the reds and greens are saturated enough for my Red-Green color blindness. I'm relearning forgotten physics from my youth!
Extending the previous comment to the multidimensional understanding. From Poincare invariance, he considers the 4th dimension as Ct, a length dimension not time. An atomic view of this will give x^2 + y^2 + y^2 + (iCt)^2 = constant; where (x, y, z) express the quantum space and (Ct) express the energy wavelength. A length with a length equation. Local higher energy implies less wavelength and so, a space contraction; this puts near GTR to the quantum world. Minkowski later joins them as space and time and so the spacetime instead of space-energy as Einstein's GTR expresses. The 4th dimension represents energy! Now, energy can be decomposed in other terms as mass-energy, kinetic energy, EM energy, weak and strong, etc. Many more wavelength-length dimensions. Your ability in resuming and explaining physics is excellent.. hope you can someday make a video referring to these ideas, thanks
Whenever I just want to play. This channel helps me to study math and science. And makes me go a little closer to the goal I have in my life. Thanks for making these informative and inspiring videos 👍
This is absolutely the most brilliantly explained and visualised video that I have ever seen, and I have watched a lot of them. What a wonderful contribution to public education. We are all richer for the author's efforts.
32:46 One major problem with stating that energy fluctuation is limited by how much its duration is short is that when talking about density it poses the question "How much its duration is short compared to what?". If two of those fluctuations appear one after the other, its basicly a fluctuation which is twice as long. I wonder if taking that into account could somehow help to solve the problem. If i'm right, the computation of vacuum energy density assumes that all fluctuations happen all the time which just doesn't make sense because in that case it's the same as if it's a much longer fluctuation, and therefore should have much lower energy.
Great explanation. As soon as I saw the difference between the predicted and observed I knew the math was going to show some crazy things going on. It sure does seem like the answer lies in getting a better understanding of how dark energy operates beyond "it's the energy of the vacuum". Maybe it's somehow tied to something in quantum mechanics we haven't found yet.
But, no. If you are in a free-falling elevator, you are floating, and a pencil "standing on its point" wouldn't have any meaning, because there would be no up or down. How can a pencil be "standing" in this situation? It can't. It's just floating, like you are.
You are my most-thumbs-up-channel by sure! One thought on vacuum energy: what, if it is not "fair" to put the highest possible energy into the lowest possible volume, then we obviously get an extreme. What, if there are more useful magnitudes for energy and length, maybe similar to Planck's deviation for radiation?
Another masterpiece! 👏🏼🏆 Thank you for the excellent videos and the excellent channel! P.S. Could you do a video explaining the electron orbitals? How are they derived from first principles? Their shapes from first principles.
Your videos rock!!! Your explanations are better than DR PHYSICS A. I love the way you add math to your explanations Can you do a video on einstein field equations?
Boy, that's why I subscribed to this channel. Magnificent explanation of one of the most astonishing facts about our universe. Thanks again for the vídeo!
This vedio helps me a lot for the test i'm about to take. You did a great job to explain things specific and easy to understand for people like me that didn't have master degree.Thank you!
PE: A masterful presentation without any shortcuts. Finally, I see where the 120 decade Catastrophe originates. I will follow your other videos. May I suggest you clarify just why the Planck constant is reduced by 2pi to your viewers: frequency in Hz, cyc/sec and frequency in radians/sec needed in the transcendental variables. Additionally, it would really help those who wonder about dark matter and dark energy if you fully explained that these parameters are solely dependent on Einstein's GR. Model independent studies are ongoing and may lead nowhere, however, we only have GR at this moment. And GR requires that DE MUST be forever a constant energy density. Does this not trouble you? I bothers me that GR, as the only gravity theory we have, is not stated as an assumption when we use dark matter and energy terms. Back to your work: Brilliant, mate.
I have literally, always had difficulty with math, I understood the concept of swapping stuff via division and subtraction etc. But never why; this video, made me understand WHY this is so important and how it helps us understand the universe. Thank you for being a better teacher than 20 years of school and tutoring
TBF, Science is about trying to prove a hypothesis incorrect, not to prove something correct. So even wrong predictions and hypothesis are valuable information.
My brain simply does not work in learning languages. Unfortunately, that includes the language of Math. That being said, I very much appreciate you putting the equations on the screen and explaining them as you do. The more I see them, the more I learn the language, and however slow and painful it might be with repetition helps understanding over time. The definition of learning.
This channel has even more subscribers than some other science channels out there, EVEN if it it’s pure math. That shows how good it is. It has also achieved that, within a year, while other channels, which have been around for YEARS, still come nowhere close to this channel’s subscribers.
The preverbal ‘Ys in the road’ in the first minute of your video offers numerous options. One neglect option is that the geophysics dynamic of inner-core super-rotation should be examined in considerable detail. It’s inverted gravity dynamic offers a legitimate portal conjecture toward dark energy. A gravity inversion starts at a radius of 3480 Kilometers in earth. This gravity inversion curiosity creates legitimate questions about our current mindset of the ‘conservation of energy and momentum’ - Also known as “The First Commandment of Modern Physics.” This curiosity is likely insightful for resolving this ‘Catastrophe’ in your outstanding video; along with many other misconceptions in physics.
This was a great, detailed explanation of a topic i have never seen a good video on, thank you very much! But when you derive the acceleration equation you still just take it as a given that the universe is expanding in the first place, right? A cause of the expansion itself is never given. Will a contracting universe "bounce" back to expansion? So solving the ultraviolet catastrophe leads to the vacuum catastrophe... Can't this(and other divergences in QFT from infinite contributions) be solved in a similar manner? Quantizing the amplitude contributions to the energy density? I had a discussion with Zap Physics about this in terms of Feynman Diagrams and they say it would be hard to motivate such an approach given how well the current theory with renormalization works.
god, these videos are SO GOOD. also: i know basically everyone hates it at school, but it's fucking incredible how powerful a concept as simple as algebra is.
I am realizing this far too late in life. Math is incredible. In 25 years of American schooling, I have had exactly ONE good math teacher. Such a shame.
Will you ever do a video on the Schrödinger equations, where it’s derived from, what’s it comprised of and what it’s useful for? Or is that not your field at all?
Yes, would like that as well. Including how the Fock we can make the Schrödinger equations work in relativistic quantum mechanics. Ouch. Thanks, I'll see myself out.
![The Dark Energy Mystery [4K]](http://i.ytimg.com/vi/cQyoYzHxdvo/mqdefault.jpg)
Loving the fact you get straight into the equations....and give really clear narrative about how they work and what they mean. I'm not a physicist, just have an interest. So many lectures aimed at folk like me avoid the equations; wrongly in my view. Keep it up!!!
Cheers!
Agreed. The derivations make it very clear what the implications are and don't require anything more complex than some calculus (and a lot of algebra) to follow. Of course it's far easier to see it explained than do it yourself!
Also a great way to weed out nonsense. Ask for the maths.
"I have a theory about how it all works and no one will listen!"
-> "Let's see your maths."
this is so true
@@PhysicsExplainedVideos I need to agree! I'm glad you went directly into the equations :D And you've produced a very well forged video! :D
Sure "the universe should have torn itself apart in a minute fraction of a second" sounds bad but I maintain that "ovens should produce limitless energy and radiation" is still the worse prediction.
But it's the only explanation where I can still absolve myself of any blame when I burn something in my oven. So I'll stick with that one thank you very much.
Oh, you and your ultraviolet catastrophe ;-)
@@theglitch312 lmao
@@WeirdMedicine ohh so that what that is
I think my stove is getting excess radiation from another universe because simmer should not boil an open pot of soup.
when in doubt, just slap a cosmological constant onto the end of the equation
More alarming is leaving an infinity in the accepted academic cosmology lexicon. If you have an infinity in your work, you made a mistake.
@@coolhand411luke6 Yeah, but we can't fix that, yet. We simply don't know enough to know exactly where we are wrong, and why.
@@chri-k Thanks for letting me know.
Yeah, that was kinda weird ngl
@@gorantev If we don't know enough to know exactly where we are wrong and why, it is clear as night and day we can't and shouldn't say we know "matter" is exactly 5% of the universe, "dark matter" is exactly 25% of the universe, and "dark energy" exactly 70% of the universe, etc., etc. THAT is just idiocy committed by the most brilliant, most educated folks in civilization... similar to what Aristotle and countless others had done in previous generations (the brightest in society coming up with some of the most stupid "explanations" for how reality and the cosmos work, here on earth and "out there" in the far distance).
For me, unless and until the contrasting explanations by Quantum Mechanics and General Relativity are brought to a seamless whole, like a perfectly fitted puzzle, things like (the "mysterious") "dark matter" and (the "even more mysterious") "dark energy" as well as "Inflation" (or "hyper-inflation," the Allen Guth imaginary energy) are just Planet Vulcan, Aether, Crystalline Sphere assertions, randomly & clever reverse engineering mathematical contraptions conjured up and invoked to make "theories" look plausible.
It's not real science when X or Y or Z "must" have happened. Any time the word "MUST" is used, it's nothing more than Bronze Age religious fairy tale doctrines and beliefs...
“Let’s take a deeper look at the vacuum of space”
You say, pushing me out the airlock.
James Barclay was not An Impostor.
2 Impostors remain.
that sounds like a Quark threat from deep space nine ''or i'll push you out the nearest airlock''
@@taufiqutomo hahahaha AMOGUS hahaha 😂🤭😆😅🤣
@@taufiqutomo Amogus
@@shaunhumphreys6714 i see youre a man of Culture aswell
Love the way you show how the most important findings and problems in physics can be derived from basic equations. Thank you!
You're very welcome!
Quite quite true!! For the mathematically respectful but not accomplished, this has been like the experience of the kid who's been taught a half year of cello but never heard any music but blue grass gospel in church, who then gets seated before a professional orchestra performing Brahms. Impossible to comprehend but not, in awe, profoundly to appreciate.
Pretty much equivalent to about a dozen+ hours of Lenny Susskind's/Stanford lectures(which are superb in their own right imo) but amazingly condensed to well under an hour. A priceless EDU Gem !
This entire video is literally only 3 pages in my cosmology textbook, it's not as condensed as you might think.
@@ObjectsInMotion Yea, I don't doubt it. I tend to exaggerate, its still a gem though.
@@ObjectsInMotion which cosmology book?
@@sdadsada8528 Barbara Ryden's
👍🍻
This channel is a treasure
Especially for physic fanboys or interested
@@TylerSolvestri yeah I'm a medical student but still a physics nerd since high school 😁
It is
@@TylerSolvestri He's on a list because fanboys who look 18 but turned out to be 12
agreed!
"We are now in a position to combine all of our previous results"
Oh yeah, it's all coming together.
As someone starting a physics degree soon, I just wanted to say that you are an incredible content creator. Your work is inspiring and clear, keep up the amazing effort!
Thank you for the feedback, it is much appreciated. Good luck with the Physics degree!
Brilliant job! I was really disappointed when the video ended after only 49 minutes. I could have listened to you for another couple of hours, at least.
Always keep them wanting more.
Thank you so much. This is incredible content. Your technical explanations are at a perfect level for a lot of us who enjoy deeper dives into physics. I hope your channel grows.
Glad it was helpful!
Very very well said.
I wish I had this video when I was in the middle of my cosmology module at university... I've always been bad at seeing the 'whole picture' as I'm learning and studying for an exam, but when I revisit summaries later on, it all fits together nicely.
Your videos are excellent.
Same here. Always takes a couple of years to sink in ;-)
@@ps200306 5 years and a Master's later, and I still don't think I know E&M.
I'm starting my PhD this year too, god help me
Thanks for the kind feedback
This must have taken an incredible amount of work to create. It was very thorough and clear. Thanks and great job!
Glad it was helpful!
And yet he is not even questioning the theory of expansion, and is quite happy to believe in theories of mysterious energy, a rather conservative mind.
@@digbysirchickentf2315 , expansion is an observational fact.
@@ps200306 It depends if your measurements are correct (they're not) and also depends how far you can see. Around the Laniakea Supercluster space appears to be contracting. Mathematical predictions of expansion do not match observations.
@@digbysirchickentf2315 , the Laniakea Supercluster is not gravitationally bound, therefore not contracting. Of course there are deviations from the Hubble flow on the scale of superclusters and below -- that's what you would expect.
I dont have any physics background but you explain things in such an easy to understand way, without dumbing it down at all.
I'm absolutely abysmal at maths, but have such an interest in physics... This channel is a bloody godsend for me! Thank you so much
Great to hear!
New sub: Back in the sixties when I attended high school, I was drawn to read Scientific American in spite of the fact that I comprehended very little of the content. In the same way-as a layperson-I am enchanted by the production values and teaching methods of this video.👍👍👍👍👍
Thanks for the feedback, glad to hear that you are enjoying the content
Aaaaaahhh… I get it!- “Dark Energy= Pi squared times energy mass velocity derivative factor over r factor multiplied by divided gravity squared plus Hawkings wheelchair minus Einstein’s whiskers” -thanks for clearing that up for a layman like myself!
I love learning stuff by listening to stuff I don't really understand like that in the background while doing chores. I don't understand most of it, but slowly I start to, or I will connect something from one thing to another thing and it will start to make sense.
I now know a little bit about basically everything, which is pretty useful.
I followed this video for about 5 minutes. Which I think is a new record for me.
Me preparing to sleep at 3am:
youtube: DARK ENERGY AND THE VACUUM CATASTROPHE
Me, reading your comment from two hours ago: Huh? it's only ten minutes to eleven.
*looks at symbols in your name*: oh, yeah, that explains it.
I hope you have slept well, when you read this.
Have a nice day!
Same here.
Me too. Just a pain in the arse when you choose a video with adverts which are broadcast at 3 times the volume of the actual video 👍
Same here. 3AM. Just about to put phone down & sleep...oh look here's an interesting news story about the EPA restoring scientific integrity post-Trump...article refers to Sharpie Gate...haha yea I remember that, let's watch a quick funny UA-cam video to recall what that was all about...hahaha...oh look, there's a new video from Physics Explained about the Vacuum Catastrophe. Fascinating! ...damn now it's 5AM.
Same here
You just explain these things in a very intriguing and understandable way.
The usage of the equations alongside your explanation helps to better understand how one comes up with these assumptions about the universe.
Cheers!
My professor asked me about what's ZPE and i found the best video on the web. Tons of thanks ❣️
Glad it was helpful!
You killed this. Thank you so much! I've always wanted to be 'walked' through this math but never knew anyone who could. Instant sub!
Underrated channel. Great job.
Much appreciated!
You both...
@@dimitrijmaslov1209 Thanks, man.
This is one of the most interesting channels on UA-cam; you do SO MUCH better with physics than many other channels. I do hope this channel starts posting more videos!
Amazing, as always. Thanks for taking the considerable time to cogently summarize and relate these concepts - I always learn something from your videos.
Great to hear!
The best physics channel I know of. Frankly, it is the first time I hear clear definitions and explanations of most fundamental concepts of modern physics, up to their limits so to speak...But to me a scale factor of 10^120 in the discrepancy of calculated and predicted values is a clear sign there is a fundamental mismatch lying at the root, and a new Einstein is needed to create a new framework to overcome it...
This is one of my favorites videos on UA-cam, so well explained and simplified, and enables you to visualize what is going on inside of the equations... You can actually see the output and you can see the transformation from concept to concrete reality.
Concepts explained in detail and illustrations are extremely helpful to imagine & understand, Thank you
Glad it was helpful!
Currently completing research for an essay regarding the cosmological constant. Your explanation of the cosmological constant problem is by some distance the best I've seen. Thanks so much and keep it up!
Your explanations are amazing. I do have to watch several times to start to get it most of the time. Can't wait to hear the ones you have planned. Who are some of your favorite physicists, alive and dead?
James Clerk Maxwell is perhaps my favourite..
@@PhysicsExplainedVideos Perfect.
The clarity here is astonishing. Blown away that you can make such complicated topics so easy to understand. First time subbing after watching just one video.
Thanks for the feedback, much appreciated!
Being a physics noob I have several questions after watching this video:
1) Plank's length and time simply denote the limit of our ability to meaningfully measure something. They are not some fundamental constants so why are they used as such?
2) By dividing by acceleration and its derivative we automatically assume that the acceleration isn't zero and changes with time. If it's not true then doesn't the whole thing fall apart?
3) Using the fluid equation for the whole Universe seems like a stretch. Can we really know that the Universe doesn't lose or gain energy as it changes in size?
4) We know that time flow varies. Around the supermassive black holes, which amount to a significant part of the observable mass, time almost slows down to a halt. and so do all the processes. Knowing this how can time derivatives be simply applied to the whole Universe without being inspected more thoroughly?
Can someone please explain?
Also being a physics noob i can't answer these with definite certainty
1. I think its because they are constants, the Planck length isn't going to change unless something fundamental with Newton's law of gravitation or the electromagnetic force changes. The Planck time isn't going to change unless the Planck length or the speed of light change, so I think because these numbers are already based on constants and equations that we know shouldn't change that we use them as constants.
2. Its because we've observed that the universe is accelerating and at an increasing rate, although I'm not sure how this would be justified before these discoveries were made.
3. It's due to the conservation of energy that we observe everywhere, so we assume (and probably have evidence I'm unaware of) that it applies to the universe as a whole.
4. I think that's due to using the cosmological principle to say that the universe is homogeneous and isotropic, so we kind of just ignore the regions of space that are particularly different like black holes.
I am in no way a professional so I might state some mistaken points but I will try to ellaborate on Spaghett's answers:
1)Planck units (natural units) are derived using gravitational constant, speed of light and planck constant: they are basically as fundamental as these things get. The reason why they were used there is because the fluctuations should constrained by the uncertainty principle, that is have a maximum value. Planck scale makes a logical cutoff. It is true that you can get Planck units derived slightly differently and those then are different from the standard size by a small coefficient, like 2pi or 4pi, but that doesn't matter too much in this case.
2) this actually shows that the universe CANNOT be static which was goal of Friedman in studying this equation. Remember, before 60s most people thought that the universe is static and this was one of the biggest blows to that idea.
You are unreally good at explaining this stuff. In the stuff I already understand as a total STEM nerd of 43 years, you basically nail the simplest explanation I've learnt or discovered, every single time, or you teach me somewhat more.
This is a rare treat. Please continue. I'll correct, of course, if there's a reason, as the scientific and didactic process lies.
But for now there hasn't been a *single* instance where I could intervene. Usually mind kind of polymath *would* intervene, but you're just too good and methodical. You cover all the bases. And you're TIGHT AS FUCK! The conciseness and preciseness of your presentation well out-shines anything I've ever seen, online, or off.
Awesome video. Excellent wrap up at the end. While the math was over my head the basic problem was very well explained. Thanks for posting this.
@Physics Explained Your videos are a real treasure for youtube. Honestly, you should be given an award for the best physics video content creation in youtube. You breathtaking high quality presentation in your videos and unambiguous in depth and detail formal explanations and physical interpretation given, is leaving really no room for misunderstanding and is an amazing achievement. Be sure your videos are not only educational but are being used also as a review material by scholars and academics. People watching your videos not only appreciate more physics but also mathematics and how these two are entangled together the one pushing forward the other and controlled by logic.
Really, best physics scholar literature content in long memory currently on UA-cam or any other public electronic media.
You have risen the bar to a much higher new level . Bravo!
The single most mind blowing and important presentation I’ve seen in some time. How inspiring, not to attempt to solve the problem, of course! One might try to calculate the size of brain you might need to attempt it, but just thinking about these equations is a trip. I suspect Ill be referring to this video for years to come. Many thanks!
I'll be really sincere here and say that I didn't know what dark energy is and was too lazy to search for some boring explanation, and you, sir, made me understand what dark energy and dark matter is without being boring, and for that I must say thank you very much!
One of the best channels out there.
Watched this on recommendation of one of my profs after explaining that fascination with the vacuum catastrophe was a major reason I was studying physics. Good recommendation prof!
Particularly fascinated by the observed/classical/quantum relationship for lambda values. It's got me thinking, 'how does one go about predicting a value for lambda-classical from first principles?' It's a good job I'm well aware (and only a tiny bit scared) that there is no bottom to the question well :).
Nice work PE. Easily the most rigorous, compressed coverage I've yet sampled on YT.
For any fans of SixtySymbols, you may like to know that Ed Copeland refers to the Friedmann equation as the "Cool Dude" equation in his lectures and notes. You have to love him
To perhaps clarify - the smaller the vibration (wavelength) the higher the energy. Wavelength and frequency being inverse to one another. E=hf. High frequency = high energy (i.e. gamma versus microwave) QM uses the shortest wavelength. Why I don't know. GR is using the longest wavelength. The vacuum of space. This is like comparing the two different sides of the MTS equation. A long long wavelength (small frequency) exists at the Dark Energy side (S side of MTS) (10 to the minus 29 g/cm3) while the shortest wavelength (Planck & 5.16 to the 93rd g/cm3) (high frequency) exists as the extreme density of a black hole (M side of the MTS equation) . Remember The MTS equation is from 0 mph to "c" in the MTS direction. In the STM direction, we go from "c" to 0mph. And with Lorentz transformations along the way. [As a side note I recall I believe out of Chicago two scientists saying that as things were brought an Bose-Einstein condensate, they approached a black hole, well, this appears evident in the MTS equation as the M (black hole) side of the equation is one of no motion. I believe I left a nervous and blathering phone message to one of them some ten or so years ago. ] What I have just realized now is that there are some 10 to the order of 120 magnitudes between the M and S side of the MTS equation. In your vacuum catastrophe you are comparing a short wavelength (high mass-high frequency ) QM environment to a long wavelength (low mass - high space-low frequency) GR environment. Why? The zero point energy of QM has nothing to do with the vacuum of space. You are mixing apples and peanuts.
An incredible channel. Mind blowing stuff. Thank-you for presenting it so well. It would be amazing if and when this problem is resolved. Hopefully in my lifetime.
Thank you very much!
Very few channels provide mathematical concepts related to fundamental problems in physics as you did , I also have made few lecture videos based on equations on UA-cam , but yours are very good. Keep doing this good work as it helps people who are interested in physics.
I love these detailed videos
They are perfect for undergrad physics enthusiasts
Writing this while tackling it 🕳️
I'll make you proud prof 🔥
I have always been taught that, when your model makes an prediction that turns out false (particularly if it is wildly false), then your first order of business (after checking your math over) is to go back through the various assumptions you made in your model, both stated and unstated, to determine where something we take as obvious or reasonable might in fact not be so.
Since the calculated value of the quantum vacuum energy depended on certain assumptions about using the Planck Time as a 'cutoff' for frequencies that could contribute to it, that seems like one plausible place we could have made an incorrect assumption. What 'cutoff' would we have to assume in order to match the observed energy density? What would that revised cutoff imply in a physical sense, and how might we justify or verify that?
Yes, it seems that the smallest imaginable time produces an excessively large energy density, so that such small fluctuations are nonexistent, for some reason.
First off, I accept your challenge.
Second, fantastic and very well done presentation on a very complex topic. A very clear approach; obviously, someone without basic physics and some calculus would not be able to follow all the arguments but certainly the general approach.
As you have shown the issue becomes a problem due to the uncertainty principle when applied to the vacuum energy. There, I feel, lies both the issue and solution. I am certainly interested in solving this problem and do feel it can be done. Obviously, any solution has to use and agree with existing physics but additional extensions must be incorporated to allow a viable solution. This I do believe is possible and some aspects that I have worked out both have experimental proof (for the assumptions) and follow current physics. Time will tell (and calculation) if my approach is valid. Your youtube topic has really help me with this problem - thank you
Up date: I've actually made some real progress in addressing these and other aspects of gravitation theory, as well (like what space curvature really is) - and my basic idea as extended to gravity does agree with experimental data and is falsifiable; it solves these and other issues but I am still a long way off but aspects are falling into place
Thanks again man for this quality content
I love your cadence and your ability to take such a complex process and explain it in mathematical terms as well as in in laymen terms and make it totally understandable.
This is the only channel I’ve ever turned on notifications for
Squeezing a billion trillion trillion trillion Andromeda galaxies into one cubic metre... He's 'avin a laugh!
It would be very expensive and time-consuming.
@@baruchben-david4196 Would be terrible for the economy!
I agree. This 4D unified, quantised subspace matter-energy field model provides a few possibilities. Exploding neutrino crystals... locally shrunk/expanded subspace cell width/gap... huge hole blown in the subspace matter-energy field... Black hole universes in black hole universe...
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Bottom-up Thought Experiment... Constraints: As few base forces and particles as possible to form a coherent, integrated 4D multi/universe model
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Subspace Charge Field: +ve charge cells (ball, quanta, +1) held together by free-flowing -ve charge. Matter-energy field conserves momentum
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Matter-Energy: Matter is focused energy.. Energy is mobile matter.. Momentum conserves velocity.. Force changes velocity and/or direction
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Positron/Up Quark/Graviton (p+): Free, out of place cell warps the field, radiating AC field cell vibration 'blip' spheres at C + 6 DC spin loops
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Electron/Down Quark (e-): Hole left behind warps the field, radiating AC field cell vibration 'blip' spheres of opposite phase at C + 6 DC spin loops
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Noton/Dark Matter (n+-): Exactly opposite phase close p+ and e- annihilate (ie. entangled pair created together (e_p) ), else a noton forms
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Nucleons: Proton: P=pep.. Neutron: N=P_e=pep_e.. Beta-: N-e>>P+e.. Beta+: P+e_p>>N+p.. Alpha: A=PNPN=PeP_PeP=(pep_e_pep)_(pep_e_pep)
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Heavier Fermions: Larger holes and chunks of subspace field rapidly disintegrate to p+s, e-s, n+-s and/or annihilate to regular = empty field
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Electrostatic Force: Recoiling blip spheres propagate. Opposite direction + and - blips form a vibrating AC bond, same sign=phase repel
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Instant-Off Long Force: AC (longitudinally blipping) subspace 'flux tube' as thin as 1 cell wide. Each cell and its -ve charge move in contrary motion
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Spin: e-s and p+s pull in the 12 surrounding cells, or -ve charge that pulls cells, that then bounce out, stabilising as a torus of 6 in/out (N/S) DC loops
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Strong Force: Spin loops merge and form flowing DC circuits between e-s and p+s
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Mass: Sum of the lengths of all strong force bonds + near electric field. Notons have compact strong force bonds, Protons' are long as 2 p+s repel
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Magnetism: Some spin-aligned atoms' p+s and e-s' strong bonds join in a shorter straight path. Energy conservation results in external force circuits
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Weak Force: Geometric structural charge balance instability. Possibly noton hits statistically tipping the balance
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Photon: Charged particles moving up and down (transmitter, atomic electron) form a radiating transverse wave blip pattern
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Double Slit: Laser light / particle centre's preceding, extended subspace distortion diffracts, interferes, forming wave guides observation destroys
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Dark Gravity: p+ traps 1 quantum of -ve charge so void cell size/gap grows (and matter's shrinks?) forming a macro -ve charge gradient
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Bang Expansion: Loss of -ve charge to the multiverse?.. Bang ejector velocity petered out, magnified in time by outward momentum conservation
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Gravity Wave: Longitudinal wave where the entire field in a large region is effected in unison for a duration
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Big Ping: A dark crystal universe collisions' intense gravity wave forms e- & p+ pairs inwardly at C that annihilate or form notons, Protons, Neutrons
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Big Bang: Ping wave collides centrally? Field blast forms matter + a large hole (then Big/Dark Refill)? Fast -ve charge loss? Noton crystal exploded?
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Black Hole: Absorbs matter and energy. Noton crystal (with a core returning to empty field)? Large hole in the field traps anything entering?
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Frame Dragging: Entire sphere of subspace cells rotating around a point in unison
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Time: Cell to cell blips take a constant time. Gravity shrinks cells so light slows but locally measures C as circuits lengthen in space & time, adding mass
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Makes more sense than making up bosons to carry force and mass, quarks that don't solve the anti-matter and dark matter problem, anti-neutrinos, loads of fundamental fields, extra spatial and temporal dimensions etc, that ultimately don't tie relativity and quantum mechanics together properly or well... They should at least be honest and call their 'spatial dimensions' geometric/field dimensions or something.. Magic Space is not my cup of tea.
If space is infinite then any finite volume occupies an infinitely small volume, relatively speaking, even though it does have absolute size.. Even though our universe has expanded, if it is finite in size in an infinite space it still occupies a relatively infinitely small volume... A problem with maths or a feature of reality? I like a finite universal field occupying a finite amount of Real Space that is infinite and propertyless.. My 4D EM Field is all that is needed to explain a coherent universe.
speaking of compactification...
I am horrible at math and when you got into numbers i got a bit (a lot) lost, but at least the colourfull letters and numbers + the calm voice were pretty epic
I can't believe how much I understood With just basic calculus under my belt. Your explanations are superb.
Quality content. I like they way you describe with equations which other channels fail to do.
Loved the math lesson. One or two commentators raised an excellent point: what can be contained and not what is measured. We occupy a timeframe (channel) which can't see the others. We can only infer those other versions do exist using the math. Compact these and it fits the predicted value. Like your mobile phone ignoring those other numbers being dialled, our universe does the same.
This is great! As a non-physicist interested in this stuff, I've heard the massive discrepancy between the energy density prediction & observation mentioned many times, but getting an explanation as to why there's such a massive disagreement is much harder to come by. The string theory anthropic explanation seems very unconvincing. How do we even know those 10^500 other universes really exist in the first place? You may as well say God is watching the quantum pot and making sure it never boils. Surely with that many universes to choose from, in at least one of them God would exist too?
Well, for some the universe's laws and theories there is a need of an external observer... or the equations will take a different turn.
@Gerard Moloney I'm speaking only from the point of quantum physics that the life is the best self improving and self replicating machine. One that you need a decade of intense study to just realise how vast and complex it is and how much more is to discover. The metaphysical context is not needed here. Especially that I didn't declare that the life is ruled by randomness and started spontaneously.
@Gerard Moloney Thanks, but I've read the Bible. In fact I was raised in a good Evangelical household and my Dad was a pastor for a time. The obsession with sin, the hostility towards the sciences, the bigotry and divisiveness did me a lot of damage and really held me back while I dealt with the emotional fallout. In fact I consider Christian indoctrination a form of child abuse. In any case, definitely not for me!
Q: if you draw a picture of a tree in a field, are you automatically IN that picture? Cheers!
Beautiful graphics and crystal clear explanations. I’m not a physicist but I actually feel that I understand a little more about the magnitude of the problems facing cosmologists now. Thanks.
First rate job of explanation, a real joy to sit back and watch, with pausing and catching up with my thinking. Also, I appreciate the use of yellow, blue, and white colors in the plots and equations, and at least the reds and greens are saturated enough for my Red-Green color blindness. I'm relearning forgotten physics from my youth!
Glad it was helpful!
Extending the previous comment to the multidimensional understanding. From Poincare invariance, he considers the 4th dimension as Ct, a length dimension not time. An atomic view of this will give x^2 + y^2 + y^2 + (iCt)^2 = constant; where (x, y, z) express the quantum space and (Ct) express the energy wavelength. A length with a length equation. Local higher energy implies less wavelength and so, a space contraction; this puts near GTR to the quantum world. Minkowski later joins them as space and time and so the spacetime instead of space-energy as Einstein's GTR expresses. The 4th dimension represents energy! Now, energy can be decomposed in other terms as mass-energy, kinetic energy, EM energy, weak and strong, etc. Many more wavelength-length dimensions. Your ability in resuming and explaining physics is excellent.. hope you can someday make a video referring to these ideas, thanks
Whenever I just want to play. This channel helps me to study math and science. And makes me go a little closer to the goal I have in my life. Thanks for making these informative and inspiring videos 👍
That was one of if not the best physics videos I have ever seen. Amazing. Great job.
Glad you liked it! Thanks for the kind words
You are always the center of your own observable universe.
Unless you are near the edge of the actual universe.
This is absolutely the most brilliantly explained and visualised video that I have ever seen, and I have watched a lot of them. What a wonderful contribution to public education. We are all richer for the author's efforts.
Great video. Seems quantum mechanics has more development ahead - it's vacuum energy is not observed nor possible.
Thanks for the feedback, much appreciated
I was amazed, shocked, and perplexed by this the whole way through. Well done on the explanations!
32:46 One major problem with stating that energy fluctuation is limited by how much its duration is short is that when talking about density it poses the question "How much its duration is short compared to what?". If two of those fluctuations appear one after the other, its basicly a fluctuation which is twice as long. I wonder if taking that into account could somehow help to solve the problem. If i'm right, the computation of vacuum energy density assumes that all fluctuations happen all the time which just doesn't make sense because in that case it's the same as if it's a much longer fluctuation, and therefore should have much lower energy.
Great explanation. As soon as I saw the difference between the predicted and observed I knew the math was going to show some crazy things going on. It sure does seem like the answer lies in getting a better understanding of how dark energy operates beyond "it's the energy of the vacuum". Maybe it's somehow tied to something in quantum mechanics we haven't found yet.
Glad it was helpful!
LOVE this content! DO NOT STOP PLEASE!
If you walk into a room and find a pencil's standing on it's point - you're in a freefalling elevator! Who would have thought :)
If the elevator is freely falling wouldn't I be in air ? I am not sure my concepts aren't good and I haven't watched the video yet
@@himanshi0003 you could be in an astronaut mall
I won't be able to walk then because my steps then accelerate me into the ceiling.
I see what you did here, Andrew.
We should be thinking in GR terms, not QM ones.
But, no. If you are in a free-falling elevator, you are floating, and a pencil "standing on its point" wouldn't have any meaning, because there would be no up or down. How can a pencil be "standing" in this situation? It can't. It's just floating, like you are.
You are my most-thumbs-up-channel by sure!
One thought on vacuum energy: what, if it is not "fair" to put the highest possible energy into the lowest possible volume, then we obviously get an extreme. What, if there are more useful magnitudes for energy and length, maybe similar to Planck's deviation for radiation?
A physics channel that is not just about concept and philosophy, amazing!
Another masterpiece! 👏🏼🏆 Thank you for the excellent videos and the excellent channel!
P.S. Could you do a video explaining the electron orbitals? How are they derived from first principles? Their shapes from first principles.
Thank you so much for this, there is not enough quality physics derivations on UA-cam
50 minutes of awesomeness right here
Excellent presentation! I have solved both the vacuum catastrophe paradox and the mystery of fine structure constant. My paper will be published soon!
Your videos rock!!!
Your explanations are better than DR PHYSICS A.
I love the way you add math to your explanations
Can you do a video on einstein field equations?
Thanks for the kind words! Einstein's field equations are on the list
You are an exceptionally gifted teacher.
Thank you, glad you enjoyed the video
Boy, that's why I subscribed to this channel. Magnificent explanation of one of the most astonishing facts about our universe. Thanks again for the vídeo!
This vedio helps me a lot for the test i'm about to take. You did a great job to explain things specific and easy to understand for people like me that didn't have master degree.Thank you!
UA-cam, please recommend this channel to as many people as possible. All it takes is the interest of the right person, it could be any of us!
yep but not me, i'm just looking at a physicist pushing dt around. it strangely amuses me
Really happy to know all the stuff professional people put into this matter.
Really !
I love your excersizes in 'equation substitution' . Together with a nice dose of logic thinking one can go a long way.
Thinking the universe should be logical to a human is setting yourself up for failure though.
PE: A masterful presentation without any shortcuts. Finally, I see where the 120 decade Catastrophe originates. I will follow your other videos. May I suggest you clarify just why the Planck constant is reduced by 2pi to your viewers: frequency in Hz, cyc/sec and frequency in radians/sec needed in the transcendental variables. Additionally, it would really help those who wonder about dark matter and dark energy if you fully explained that these parameters are solely dependent on Einstein's GR. Model independent studies are ongoing and may lead nowhere, however, we only have GR at this moment. And GR requires that DE MUST be forever a constant energy density. Does this not trouble you? I bothers me that GR, as the only gravity theory we have, is not stated as an assumption when we use dark matter and energy terms. Back to your work: Brilliant, mate.
Fantastic tour the force through 20th century physics and it’s implications for cosmology. This is very hard to do well. Thank you.
Glad it was helpful!
I believe that I understood perhaps about 1% of what you covered in this video, however enjoyed every minute of it.
More gold. Who would’ve thought that the upload of this video and a successful static fire of Starship SN11 would occur on the same day!
Inspirational indeed. A most excellent exposition, thank you very much.
Another amazing video. I would love it if you do a video that explains why general relativity does not mathematically fit into quantum mechanics.
Absolutely agree, looking at why the perturbative method fails for general relativity would be a blast
I have literally, always had difficulty with math, I understood the concept of swapping stuff via division and subtraction etc. But never why; this video, made me understand WHY this is so important and how it helps us understand the universe. Thank you for being a better teacher than 20 years of school and tutoring
I make an error this big on my paper: get it marked wrong.
PhD's make an error this big: write grant proposals.
😆
TBF, Science is about trying to prove a hypothesis incorrect, not to prove something correct.
So even wrong predictions and hypothesis are valuable information.
@@masstv9052 He was being satirical. 😊
My brain simply does not work in learning languages. Unfortunately, that includes the language of Math. That being said, I very much appreciate you putting the equations on the screen and explaining them as you do. The more I see them, the more I learn the language, and however slow and painful it might be with repetition helps understanding over time. The definition of learning.
This channel has even more subscribers than some other science channels out there, EVEN if it it’s pure math. That shows how good it is. It has also achieved that, within a year, while other channels, which have been around for YEARS, still come nowhere close to this channel’s subscribers.
The preverbal ‘Ys in the road’ in the first minute of your video offers numerous options. One neglect option is that the geophysics dynamic of inner-core super-rotation should be examined in considerable detail. It’s inverted gravity dynamic offers a legitimate portal conjecture toward dark energy. A gravity inversion starts at a radius of 3480 Kilometers in earth. This gravity inversion curiosity creates legitimate questions about our current mindset of the ‘conservation of energy and momentum’ - Also known as “The First Commandment of Modern Physics.” This curiosity is likely insightful for resolving this ‘Catastrophe’ in your outstanding video; along with many other misconceptions in physics.
This was a great, detailed explanation of a topic i have never seen a good video on, thank you very much! But when you derive the acceleration equation you still just take it as a given that the universe is expanding in the first place, right? A cause of the expansion itself is never given. Will a contracting universe "bounce" back to expansion?
So solving the ultraviolet catastrophe leads to the vacuum catastrophe... Can't this(and other divergences in QFT from infinite contributions) be solved in a similar manner? Quantizing the amplitude
contributions to the energy density? I had a discussion with Zap Physics about this in terms of Feynman Diagrams and they say it would be hard to motivate such an approach given how well the current theory with renormalization works.
Excellent presentation of the materials
Many thanks!
god, these videos are SO GOOD. also: i know basically everyone hates it at school, but it's fucking incredible how powerful a concept as simple as algebra is.
I am realizing this far too late in life. Math is incredible. In 25 years of American schooling, I have had exactly ONE good math teacher. Such a shame.
Great that you are calling it Hubble parameter rather than constant.
Extremely well made video! Thank your for keeping on making these videos, I might even think of becoming a patreon in the future :)
Much appreciated! Thanks for the kind words of encouragement
The best physics channel I have ever seen in youtube!
Will you ever do a video on the Schrödinger equations, where it’s derived from, what’s it comprised of and what it’s useful for? Or is that not your field at all?
also, requesting a vid on inflation theory! Really, really large numbers really excite me!
Yes, would like that as well.
Including how the Fock we can make the Schrödinger equations work in relativistic quantum mechanics.
Ouch. Thanks, I'll see myself out.
This channel and PBS Spacetime are the best