With all of the ugliness going on in the world right now, these videos remind me of how incredible humanity can be at our best. Thank you very much Prof Carroll.
@srghma Жыл бұрын
What ugliness you are thinking about ? (Just want to know)
@oldcowbb10 ай бұрын
@@srghma everything was about covid 3 years ago
@GausEdukativniCentar3 жыл бұрын
I am a theoretical physicist, working in the field of quantum gravitation, and I can say that this is the most straightforward explanation of the concept of renormalization compared to a lot of actual physicist books. You got yourself a new subscriber, Sean!
@frun Жыл бұрын
Does a black hole center have lower energy density, than a crust? In holography they renormalize the fields on the boundary towards lower energies. Going from the shell towards the center we encounter lower energies, no?
@animefurry35087 ай бұрын
As a person who studies Philosophy, and likes Science (especially Physics) I'm super happy to see a serious Scientist that takes Philosophy seriously and gives it the proper respect it deserves! Love your work! Keep it up!
@captainzappbrannagan4 жыл бұрын
This is the best explanation i have ever seen on why infinities occur, why they aren't real, and how we correct for them without skewing results. Keep the great vids coming!
@atanumaulik70939 ай бұрын
Hundreds of thousands of people learning about renormalization in QFT. Astonishing! There is hope for mankind.
@silent_traveller74 жыл бұрын
I am really enjoying how deep we are going here, keep doing Dr.Sean!
@Cemselvi19884 жыл бұрын
Very cool comment
@oliverwinters14064 жыл бұрын
That’s what she said
@iziskin1234 жыл бұрын
Definitely the best public explanation of renornalization that I have ever seen. AND he even justified it by citing the fact that when we renormalize we implicitly accept that we are just writing an EFFECTIVE field theory that approximates some deeper theory that describes interactions at energies above the cutoff (e.g. maybe String Theory, but probably not) Beautiful!!
@quantumgravity77044 жыл бұрын
I am not sure your interpretation is correct though. In renormalizable theories (not EFTs), the renormalization scale is arbitrary and there is no need for new physics at some scale, unlike EFTs. In EFTs, you can still renormalize your theory order by order choosing your renormalization scale arbitrarily (hence the RG group flow just like renormalizable theories) but there is a cut-off. These are two different things. Renormalization itself does not necessitate any kind of physics beyond a renormalizable theory (e.g. QCD).
@iziskin1234 жыл бұрын
@@quantumgravity7704 The modern (majority) opinion in the field is that QFT is a framework for writing effective field theories. Given the symmetries (and broken symmetries) that we observe at the energy scales probed, no matter the form of the "True" theory that applies at higher energies (Strings, Loops, etc), the world will "effectively" appear to be composed of quantum fields.
@themenace47164 жыл бұрын
I have an exam tomorrow, but who cares? Sean Carroll posted a new awesome video! :-)
@calwerz4 жыл бұрын
Poor Sean, wanted to keep the episodes short, but they are just getting longer and longer. :) I'm not complaining tho.
@nibblrrr71244 жыл бұрын
Curiously, the opposite of his hair! :3
@picksalot14 жыл бұрын
Renormalization has become my favorite topic in this series of lectures, and Ken Wilson is a hero. I'm so glad that he figured out how to get rid of all those "infinities." There is a point when concepts exceed available experiments, and it becomes a necessity to have a precise language to communicate coherently. Thanks
@Daniel-ih4zh3 жыл бұрын
Like a lot of big discoveries, Ken Wilson wrapped up the ideas of his predecessors like Gel-mann.
@dude1243534 жыл бұрын
This has very quickly become my favourite series on youtube, thank you for the in-depth explanations Sean.
@grahamdlawton3 жыл бұрын
I felt that this video was where the prep work started to crystallize. Sean is a star - love the style. Cannot help smiling when Sean pauses to clarify x, y and z and draws a little axis ……….. then rolls on to Fourier transforms, Hamiltonian, Lagrangian, Hilbert space and solving the Schroedinger equation in about 10 secs without skipping a beat. Definitely looking forward to the rest of the videos (not lectures)!
@rtheben2 жыл бұрын
This soothes my soul, thx. I don’t mean all that crap mixing pseudo spirituality with physics, just staying on the logical and technical ground of it it’s so rewarding
@kjrunia4 жыл бұрын
3:30 Sean Carroll is the Bob Ross of painting lush quantum fields with little trees with branches coming out.
@coinstudiocrosstec87454 жыл бұрын
Everytime a probability wave collapses, it's a happy accident
@kjrunia4 жыл бұрын
CoinStudio Crosstec I love that!
@Psnym4 жыл бұрын
We need Sean Ross Happy Fields memes and Tshirts... NOW!
@kjrunia4 жыл бұрын
Denis Goddard Ha! Yes!
@martinds48954 жыл бұрын
Haha exactly!🤣
@aravin3144 жыл бұрын
This series is precious
@captainpints4 жыл бұрын
Yep. Him and the Brian Greene ones are so good. The format is awesome and in particular the Q&A stuff.
@anandhiremath25302 жыл бұрын
I am not a physicist but have a genuine interest in it. So glad Dr. Carroll explains it so beautifully and includes math to explain concepts that are understandable for a non-mathematician like myself. Can’t wait for more like these on other topics from Dr. Carroll. Thanks again 😊
@pamelacollins11534 жыл бұрын
Absolutely fascinating and enlightening. This is the first time I’ve heard the problematical infinities explained. Thank you!!
@Dr10Jeeps4 жыл бұрын
As a (semi-retired) Canadian professor of psychology, apart from my own field of social psychology, one of my passions is physics. During this pandemic lock down I am thrilled to be able to watch KZbin videos from some of my favourite physicists including Sean Carroll, Brian Greene, and Lawrence Krauss. What a shame it will be when these videos come to an end. The promotion of the physical, biological, and social sciences in society is a must when certain populations, especially in the United States, appear to be turning away from science and filling their knowledge void with religion and superstition. Humanity needs a greater knowledge and understanding of science, not superstitious nonsense.
@Bazzo614 жыл бұрын
Totally agree and very elequently expressed.
@zwz.zdenek4 жыл бұрын
There is no question that the basic claims of religion are false. One has to wonder though why this meme managed to survive for so long. Is it the ferocity in fight it gives its bearers? Do groups need a strong common "banner" to tell friends from foes? Or is it the fact that a false positive in the wild is just safer than a false negative?
@psycronizer4 жыл бұрын
@@zwz.zdenek when you get right down to it, I have found, by asking many people, it is the fear of absolute death. It's one of the greatest challenges of being sentient, and, born in a time when death is an absolute certainty. Put it this way, imagine a time in the future where you could chose, to either age naturally, and die, or age naturally, and transfer your body to a younger one, or not age at all, or transfer to some synthetic body, I wonder how many would allow themselves to end, given that life in the future could be a total transformation from the crappy way we live today, chasing wealth accumulation just to live out our last days in some level of partial comfort, if life in the future, due to technology, was a utopian paradise, the need for a god, or religion, becomes less necessary to believe in, to be indoctrinated in. I don't think that religions are needed to teach people to be decent to each other, given a paradise, there's no need. If we can reach a state where technology can really save us, god , the notion of it, becomes meaningless.And it is my hope, that one day, gods and religions are just an ancient illogical curiosity, some are already.
@b-manz4 жыл бұрын
Religion and science are able to exist together. If someone makes an excuse by claiming religion they are simply not smart enough to work out the science. Doesn’t make their religion wrong.
@b-manz4 жыл бұрын
@@zwz.zdenek interesting to know how you now this. Prove it.
@jeffspaulding98344 жыл бұрын
I do not have the education to understand this. I'm just a guy with a bit of math (nothing above diff eq) and almost no physics outside the occasional Wikipedia binge and memories of a basic physics class fifteen years ago. While I certainly couldn't follow much of this subject matter, I do feel like I got something out of this, even if it's only a small intuition of how physics theories work. The fact that I got anything at all out of the video is a testament to your presentation skills. Excellent video!
@martinmiller41814 жыл бұрын
Hi Sean, this is the first one I've caught so far, will definitely go back and watch the others. You've pitched this at the absolute perfect level for someone like me, who kind of gets what your talking about but doesn't have the maths to back it up! Thanks very much for all you do in promoting physics!
@forbdonut0yt4 жыл бұрын
A welcome break from everything going on right now. Thank you!!
@esperancaemisterio4 жыл бұрын
Stopping everything and starting to watch, as usual! Thanks Sean!
@iamnixflix4 жыл бұрын
Prof. Carroll, my gratitude field is in the Ultraviolet 🎇 Thank you for taking the time to share this knowledge
@59ratfink4 жыл бұрын
Thank you Sean for this amazing series. Wish i was younger and smarter to really grasp all these fantastic ideas but what i can grasp is so unbelievably satisfying. i can tell you truly love teaching physics and it shows.
@youtubebane7036 Жыл бұрын
This is a pretty deep dive into physics right here I've learned a lot already. I'm kind of sick and tired of all the beginning level programs and videos that assume that you can't follow the math so they don't have any equations or anything and although I'm not a mathematicia and I can't really follow the math John Carroll does a good job of explaining what the numbers mean as he's writing them and I don't have to know how to do any of these equations myself just by listening to him I understand what they mean and that is the main point for me cuz I've always been mystified by how they convert things of the real world into the different number value so they do their equations and he does a good job of explaining that
@faisalsheikh78464 жыл бұрын
Sean Carroll and Brian greene sir my role model sean sir lot's of love from india
@nijram154 жыл бұрын
This was definitely one of the better lectures of this serie! I really enjoy the (relative) simple but still encapsulating math in order to show the important insights.
@sashwattanay4 жыл бұрын
Sean Carroll is a legend! I love him.
@RoryOConnor4 жыл бұрын
Some of the nuts /bolts/secondary concepts/mechanisms of physics are just a inspiring as more main stream bells & whistles! Really Fascinating lecture!
@uzulim92344 жыл бұрын
thanks for this, it's a good complement to the more technical and localized introductions to this topic.
@Dr10Jeeps4 жыл бұрын
Wonderful presentation! Thank you. I really look forward to your KZbin videos.
@tune490 Жыл бұрын
Thank you Sean Carroll, this was a great lecture, one of the few lectures I watched at normal speed :D
@Pedro-un3mk4 жыл бұрын
Awesome explanation!!! Fantastic Sean!!
@Robinson84913 жыл бұрын
These are such amazing lectures. Especially these last two-three QFT lectures are so useful, gaining so much knowledge and finally understanding terms I heard about a lot but were a mystery to me, like the meaning of UV-cut off for instance. You're awesome Sean! Thank you!
@rockapedra11302 жыл бұрын
Thanks for these excellent videos! I especially appreciate how you point out the parts that still need work. Some physicists talk as if all is known, my guess is it will never be. We just add piece by piece as we learn more. The progress and the relentless effort are still amazing even if, as always, a new more comprehensive theory will likely arise in the future that will recast some of these things in different concepts that have more predictive power.
@andreavecchione93774 жыл бұрын
Very very very beautiful lecture, I really appreciated it. Thanks professor Carroll and please don't stop making video-lectures like this one.
@Quantumpencil4 жыл бұрын
Best Physics Series on youtube. Keep them coming Dr. Carroll!
@rc59894 жыл бұрын
Dr. Sean Carroll, in the Q&A would you spend some time on the “quantum foam” of the vacuum? I understand that Feynman virtual particles are placeholders for the complicated back-reactions of the fundamental fields. But what about these foamy short-lived particles at the ground state? Thank you.
@wagsman99994 жыл бұрын
Really appreciate these videos. Makes you wonder if we will ever wake up one day with no more mysteries to solve, and how depressing that day might be. But for now the rabbit hole is still deep!
@adhdasian18964 жыл бұрын
Interactions was a doozy, Normalization was no less! ty Sean for getting us through :)
@briancannard73354 жыл бұрын
Just. Wow. You made my Spring.
@Bootlebarth2 жыл бұрын
This is a brilliant series, the best I have seen. Thank you for attempting to educate us.
@genechen38693 жыл бұрын
This is so neatly presented, thanks for making it public.
@trxe4204 жыл бұрын
I feel like I am getting a free education on my favorite side hustle. This is really awesome and noble of you Sean! Side note, seems computer programmers really like physics. Several I work with are studying the subject. I wonder why that is. Maybe the simulation is reality after all:)
@viewer30914 жыл бұрын
I hope there are some young Einsteins watching and learning from these and what Brian Greene is doing !
@bmoneybby4 жыл бұрын
Present 🙋
@ssshurley4 жыл бұрын
I’m here too! However, I would rather pass all of this off to my 6 year old daughter!! So she can conquer space and I can have a mars hotel 🏨
@Psnym4 жыл бұрын
It’s a golden age of self-learning
@David-tp7sr4 жыл бұрын
What is Brian Greene doing that I am missing out on?
@IzzatZubir4 жыл бұрын
And Sabine Hossenfelder
@dzanc4 жыл бұрын
Ooh here comes the big stuff
@mistermxyzptlk35734 жыл бұрын
Amazingly clear and insightful, as always. Thanks a lot and I hope you will write a textbook on these thorny topics one day.
@dullyvampir832 жыл бұрын
Could you explain at 38:00 what the time derivatie of the Field is? As far as I understand it, it is not moving like a particle.
@trucid24 жыл бұрын
This is great stuff. You make it seem so simple.
@salahsedarous76163 жыл бұрын
Outstanding teacher, thank you
@davidseed29392 жыл бұрын
at 11:34 i just now see, that the problem is that from E1 to E3 you have E_bar adding one way round the loop and minus E_bar going round the other way
@newhoggy4 жыл бұрын
At 10:00, you say that energy (E bar) can be any number from minus infinity to plus infinity and you add them up and what you get is an infinitely big contribution. Can that statement be clarified further because my intuition tells me that adding everything from -∞ to +∞ is zero.
@icedhockey14 жыл бұрын
Thank you. Well done, great format, enormously appreciated.
@ssshurley4 жыл бұрын
The series is great! Alway look forward to every video...
@bipinsonawane5312 Жыл бұрын
Though it, the explanation, seems to be very lucid and simple, but really it is not. A teacher knows the handwork behind it. It is your skill Sean. Great, fantastic ! Keep it up ! Thanks!....
@ToriKo_2 жыл бұрын
11:30 “maybe you shouldn’t have been so naive.” Classical vs Quantum. Real world etc. I should watch this part again 13:40 philosophy of counterterms 18:00 Effective Field Theory (below a certain cutoff) vs TOEs 23:00 philosophy of why we are allowed to ignore this aspect of our physical system 30:00 dimensional analysis 39:51 I think you meant to say ‘The actual Lagrangian is the intergral of the Lagrangian Density over [ *_time_* ]’. 50:00 relevant, marginal, and irrelevant interactions 55:00 is GR renormalizable? We is/isn’t that important? 58:40 the payoff. “You don’t need to know arbitrarily complicated things to do Effective Field Theory. Tell me what Fields you have and what symmetries they obey, I can go and use this theory, it will come with a small number of parameters that I can measure; I can figure out the Effective Field Theory at low energies really simply.” 1:05:00 Feynman Diagrams are story’s we tell to gain some intuition, what is the Field actually doing? 1:12:00 “when you really probe Quantum Fields, your probing them at some scale, and that scale matters. This is where renormalization matters, it is a physical effect.” What I don’t understand is that virtual particles don’t exist, so how non-physical virtual particles accounting for this physical effect? Also I don’t think I understand properly the link between virtual particles and renormalization. Sean goes on to talk about the Higgs Mass mystery after
@AdamGenesisArt4 жыл бұрын
I love how down to earth this guy is!!!!! Great stuff. [GxQ=Universe]
@emilylowrance79304 жыл бұрын
joyfully informal!!
@Grasuggan224 жыл бұрын
Question: what if we did the double slit experiment, recorded on a harddrive which slit the electron went through. Then we deleted the harddrive directly or after 5 minutes. Then we can rule out or confirm if the experiment is dependent on a (subjective) observer. Owing to if there is a interfenerce pattern or not. But I assume this already is done. The result would be that there is no interference pattern, I belive, but then we can rule out that the wave collpase when we are looking at it.
@zwz.zdenek4 жыл бұрын
They often make a popular phrase that the mind is what makes an observer. It doesn't work like that. For a particle to remain ambiguous, there needs to be very little energy exchange between it and the environment. Once there is such exchange, it already counts as an observer and the result is ruined. A computer recording the information is a much bigger "leak" than needed. On top of that, the retention of superposition is bounded by time. So even if your computer was processing very low energy, you would have to delete the information in femtoseconds, or the decision would have propagated to the electron ruining the interference once again.
@DApple-sq1om3 жыл бұрын
Good Idea. We know a rock can be an observer and destroy the interference pattern.
@TheDarktsun3 жыл бұрын
I found the dark energy pressure estimate under an Emergent gravity model. It would be interesting to compare with an order of magnitude to the cosmological constant at quantum scales.
@VideoFunForAll3 жыл бұрын
Pushing the effective field theory to high E's and then concluding you need new physics (i.e. postulating more particles or forces to be added to the zoo) because the results contradict experimentation implies that the theory is already presumed to be perfect but just needs some adjustments from new experimental information. Science becomes fine-tuning without new paradigms, something that would eventually collapse in absurdities.
@Petrov34344 жыл бұрын
This is an absolutely outstanding lecture -- thank you soooo much !!! PS: Could you address the "cosmological constant" in more detail. Including your comment at the very end of this lecture.... about only two items that ... Many thanks in advance... PS: I keep re-watching episodes to better understand -- for example --- for decades I couldn't figure out just why (and how) eV unit is being created/used.... PS2: "..electron is, as we know, NOT a fundamental particle -- it is just an excitation in electric field " .... breaks my electronics engineer's heart ... ;-))
@DApple-sq1om3 жыл бұрын
For many purposes the electron can be considered a particle.Many great physicists considered them as particles. Sean is in the other camp .
@eelcj1 Жыл бұрын
the effective field theory looks similar to the method of truncating an asymptotic (divergent) series that comes from a singular perturbation system. Truncate the series and take the limit of the epsilon to zero to get the leading order solution... Are the two related?
@TenzinLundrup4 жыл бұрын
(1) It would be great to know where Lorentz invariance comes in. I remember reading that the Feynmann diagram approach maintains this invariance for each term. (2) Does a conformal field theory lack a cut-off? (3) It would help to know how the mass of the Higgs is measured. It is obtained as a peak in some curve. What does that curve mean?
@youtubebane7036 Жыл бұрын
It seems to me that units can be replaced with terms like cardinalities. Also the different algebraic terms that stand for different numbers but have to be the same for you to do mathematical operations with a very similar in my way of thinking. So how do you assign values to cardinalities or units and make them a hierarchy? I think imaginary numbers is the solution or something very similar
@youtubebane7036 Жыл бұрын
Seems to me that the ebar going down in the Ibarra coming up with cancel each other out as you already said the same way that these counter operations are expressions or whatever you called them do. Kind of like how a negative integer and a positive integer of the same value would make 0
@SuperMaDBrothers2 жыл бұрын
1:22:30 how would a multiverse explain this? What is even meant by multiverse?
@eefaaf4 жыл бұрын
You do exactly in handwriting what I do ever since I could write... my hand is slower than my thinking, so I skip letters, start writing what I am thinking of next.
@guitarika84772 жыл бұрын
Hi, you said that the effective charge is dependent on the cutoff scale but I thought this was only true for bare charge ( couplings) and that renormalized charge (couplings) are dependent on energy at which one probes it but is independent of the cutoff
@youtubebane7036 Жыл бұрын
I've noticed that the values for all these units depend on time or space as a multiplier or some kind of factor in the equation. What what is the value for time in space?
@kquat78994 жыл бұрын
Brilliant series.Thank you.
@MrWicoe4 жыл бұрын
Hey Sean, thanks for these videos! One question that I still struggle with (and see contradictory answers) is whether Virtual Particles have any physical significance or if they are just mathematical "tricks" for doing calculations of complex field interactions. If they were the latter, there would be situations (like a free particle in a non-interacting field) where they should not matter. However, in this video, you indicated that they still cause vacuum polarization. Besides, as I understand it, Virtual Particles are directly responsible for static field forces (i.e. when a static electromagnetic field pushes/pulls on an electron). Is there a reason why they cannot be accepted as existing in reality, i.e. as another type of particle that cannot be directly observed and violates some principles, but is otherwise perfectly "real"?
@martinds48954 жыл бұрын
Great video, thanks Sean.
@miriamhatira75054 жыл бұрын
Hi the video is so good .. Can you maybe do more videos about renormalization group equation and fixed points ? I'm interested in fixed points of renormalization group equation of high partial waves of two nucleon-scattering it will be very helpful
@luizdegrande7112 жыл бұрын
Would fields be mere fictitious instruments to avoid the idea of unmediated action from a distance?
@dr1971bz4 жыл бұрын
A couple of questions. 1. Can you think of the original UV catastrophe or the Plank theory of Black body radiation in terms of EFT? 2. A little more prosaic, what hardware & software are you using to produce your videos?
@yodajimmy25744 жыл бұрын
1:21:00 Then we need a way too heavy mass which account for the observations. I mean literally wayyyy toooo biiiig. And gravity is weak. So it's even wayyyyyyyyy toooooooooo biiiiiiiiiiiig.
@yodajimmy25744 жыл бұрын
26:00 Why arbitrary E*? Shouldn't the maximum energy which can affect us have a wavelength greater than planck length?
@piathus9184 жыл бұрын
Question about the loop-feynman diagram? What about using a harmonic oscillator on the loop? Could this solve the infinity of this loop ,an oscillator has an infinity momentum?
@jamesr35052 жыл бұрын
This lecture is awesome, except for one thing: The plot of the fine structure constant vs. energy should show that it’s asymptotically the true value. Unfortunately it appears as if the electric charge measured increases without bound.
@charlesdurrett28784 жыл бұрын
At 30:00 shouldn't the dimensionality of h-bar be [h-bar] = [M][D]^2 ? h is an amount of work needs to be done to create a photon. How quickly that work is done is the energy needed as per Planck's E=fh. Dimensionality of f-frequency would be [f] = 1 / [T] so that [E] = [M][D]^2/[T] but [h] is only [M][D]^2. Really like your series. Cozy.
@nathanisbored4 жыл бұрын
[E] = [M][D]^2/[T]^2, not [E] = [M][D]^2/[T]. you get one [T] from [f] and the other from [h]
@yodajimmy25744 жыл бұрын
43:00 You're not simplifying anything here. It'd be better if you've showed us the equations. Why this happened? Because for the people who don't know L density (energy over time), scalar field (scalar function) to the power something, it can't exist in L density. What does that 'in' means there?
@LarryBorsinger4 жыл бұрын
Is the numerical discrepancy in Higgs mass and the cosmological consented related to the relative difference of electrical and gradation always forces?
@at0mly4 жыл бұрын
Sean, you might want to turn off notifications on your iPad. We can hear you get a text message at 7:21! :)
@dondovahkiin78994 жыл бұрын
I finally get why astrophysics is important. We simply cannot creat tests here on earth to test tgese ideas. We have to look in nature fro answers.
@DargiShameer2 жыл бұрын
Great Explanation 😍😍😍😍😍😍😍
@jeanenry3 жыл бұрын
The cut-off idea came out with Debye's Specific heat theory, only wavelengths of interatomic distances were included, circa 1905. More rip-off!!
@yodajimmy25744 жыл бұрын
I want to know what would be the true cut off, a limit where everything interacts, above which nothing can be measured, nothing can be affected. Some value for which E* would give a theory like Heisenberg's uncertainity principle.
@barefootalien4 жыл бұрын
Wat. You had a fairly interesting question until you invoked Heisenberg, which... seems to have absolutely nothing to do with this, though it's possible I'm wrong. You certainly don't need ultra-high-energy physics to invoke the uncertainty principle; it's just a natural consequence of the introduction of wave mechanics into things. As for this highest limit you asked about... our best current guess is the Planck energy, though that's really just the answer to the question, "What if you set all the dimensionful constants of the universe equal to 1 and then do some dimensional analysis to figure out what 1 unit of that energy would be, converted back to SI units?" If that doesn't sound like a very promising guess... yeah. It probably shouldn't. Since, in fact, there are several other ways to derive very similar units, and there's nothing particularly special about the Planck units in comparison with those ones, and no particular reason I can think of why they should be treated as so significant as to define such lofty concepts as maximum possible energies, granularities to space and time, etc.
@yodajimmy25744 жыл бұрын
@@barefootalien I meant a limit of energy above which nothing can interact, which means talking about such a thing greater than this limit would be meaningless, like for a constant momentum, things become uncertain, a set of energy greater than that when needed to be observed would become uncertain like which is the energy you want? Any energy greater than that would have the same effect in our world.
@timseguine24 жыл бұрын
So if I understood correctly: quantum gravity is not renormalizable essentially because it couples to too many other fields?
@PavlosPapageorgiou4 жыл бұрын
Is it one of the options for the universe to have some maximum energy density? It would make the field equations non linear at higher energies, but what if linearity is an approximation?
@denmaroca25844 жыл бұрын
There should be a msximum energy density within the universe because at some point the energy density would be sufficiently high to form a black hole, which would then promptly evaporate by emitting a load of particles and spreading the energy around.
@byronwatkins25652 жыл бұрын
I accept that every Feynman path is possible and must be considered; however, it does not automatically follow that all paths are equally probable. Consider applying B-E or F-D statistics to weight respective virtual particles in the sum (integral). Also, why cannot Ebar traverse the loop in the opposite direction? It would seem to me that virtual particle pairs must necessarily go both ways and form standing waves around the loop.
@youtubebane7036 Жыл бұрын
How do you calculate Phi without getting infinities? Is there a cutoff?
@brucesinclair52314 жыл бұрын
I thought I had read that the LHC search for the Higgs boson "expected" a mass in the 120 Gev range. How does this jibe with your discussion of the hierarchy problem?
@Ghan044 жыл бұрын
When we talk about something like the electron field with a configuration that looks like a particle at some location in space, what implication does this have (if any) on the field's configuration in the rest of space? If we set an E* cutoff at some value near the Planck scale, it would seem that that would place an effective maximum energy on the field across all of space. It seems clear that the different modes of the field don't have an infinite contribution to the vacuum energy based on our observations, so is it possible instead that any given field has some constant energy across all of space that is instead required to be conserved? (I.E. the distribution isn't uniform, but the total energy is constant)
@cazymike874 жыл бұрын
Its the other way arround im guessing . The cutoff E* its set for an interaction ( and as you know an interaction is happening in a deffinitive space ) ....The total energy its not conserved , because the total energy its not fundamental . Whats fundamental its the wave function of the universe , and that universal wave function has all the possible energies all the time ... so its not about conservation of energy .....Because Energy its NOT fundamental !
@cazymike874 жыл бұрын
If you still dont understand picture this : if you remove an imaginary point from an imaginary circle , then that imaginary circle still gonna be a circle no matter how many points you remove . Why? Because the imaginary point really doesnt matter ! Its just not what the imaginary circle its about
@cazymike874 жыл бұрын
The reason why it seems that energy its conserved its because, like I said the Universe doesnt care about the conservation of energy at all , what its about its that its something that defines reality...If you try to go beyound that you will have infinites , and black holes etc ..... our reality seems to be emergent. Even if you will get a good working Theory of Everything , then it still gonna be NOT testable , because it will go beyound the point of reality emergence .
@mcsquared43194 жыл бұрын
The Higgs mass is not a constant. It is a constant for proton-proton collisions. What is the Higgs in electron-positron annihilation? Maybe a pair of photons with a total spin of 0... in the reference frame of the electron-positron couple... It would be nice if you could comment on the path from QFT to QCD.
@TIENTI00004 жыл бұрын
best explanation ever
@youtubebane7036 Жыл бұрын
If you can convert time or space or distance into Mass cannot the opposite be said to be true?
@bohanxu61254 жыл бұрын
Your explanation of the origin of infinity (in say 3+1dimension phi-4 theory) is that it is some kind of difference between classical theory and quantum theory. It doesn't make sense to me (and I don't really understand what you meant). If you are talking about non-measurable quantity like absolute energy. Then it's a fine argument. But scattering amplitude is measurable. I don't even know if {phi-4 in 3+1D is a well-defined quantum theory} or not...or it's only well-defined as a low energy effective theory after renormalization? is there a known definitive answer to this question?
@joshua31714 жыл бұрын
entropy is the inability of the electrical field to maintain bonding when interacting with the weak(muonic) and strong(tauonic) fields, an interaction that exceeds these electrical bonds part of my idea for the Yang-Mills existence and mass gap for the Millennium Prize, would you like to have a share in the 1mill US??
@grahamwykes4 жыл бұрын
How does the vacuum energy calculated by this method compare with the vacuum energy during the inflationary period? Could the vacuum energy be responsible for the rapid inflation? Perhaps a working theory of quantum gravity would tell us that gravity almost cancels the vacuum energy somehow.
@Cooldrums7774 жыл бұрын
So this is my takeaway from considering a combination of dimensional analysis and QFT; Is my description below a true statement??? With the possible exception of Quantum Gravity and black holes, one should be able to completely describe the universe with just a few key concepts. 1)The Four natural fundamental quantities of nature (mass, distance, time and charge) 2) The abstract platonic object of mathematical structures 3) The equation of QFT (I guess this really is just an element in the set of number 2 above) 4) A sprinkling of a handful of the constants of nature The above should be all that one requires to describe the entire functionality of the universe.