Quantum Fields: The Most Beautiful Theory in Physics!
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BACKGROUND VIDEOS:
Basics of QFT: • QFT: What is the unive...
Quantum Gravity: • The Trouble with Gravi...
Basics of Quantum Mechanics: • What is Quantum Mechan...
QM model of the Atom: • The Quantum Mechanical...
Quantum Chromodynamics (QCD): • QCD: Visualizing the S...
CHAPTERS:
0:00 - Historical perspective of modern physics
1:50 - The advent of Quantum Mechanics
5:00 - The problems with quantum mechanics
6:52 - What is Quantum Field Theory?
9:25 - How QFT explains force mediation and decay
10:53 - How QFT is also incomplete
11:44 - The most beautiful theory in the universe!
12:41 - Further study with Brilliant
SUMMARY:
Quantum field theory or QFT is the basis of the best theory we have in physics today to explain nearly everything, called the Standard Model of particle physics. What is Quantum Field theory? Why is it necessary? How is it different than quantum mechanics?
Classical mechanics indicates that an orbiting electron creates electromagnetic radiation which means that it would constantly lose energy, and fall to the nucleus. This does not happen. Quantum Mechanics solved this problem by showing that electrons travel in quantized orbits at their lowest energy state, and that they do not orbit but exist as a clould around the nucleus.
In quantum mechanics, objects are wavefunctions described by the Schrodinger equation. The location of a particle is unknown until the moment of measurement. We cannot know where it is beforehand, only the probability of finding it at any specific location.
This is a great model but it also has some problems. First of all, quantum mechanics is not relativistic. It will give you the wrong result if the quantum object is moving close the speed of light. The practical result of this is that as it doesn’t incorporate a speed limit, the speed of light, needed to make causality work. It allows for two measurements to influence each other faster than light. This would mean that there would be some reference frame in which the future could influence the past, breaking causality.
A second problem with quantum mechanics is that it only tells you how a particle evolves over time. It does not tell you how it is created or annihilated. So it can’t account for things like beta decay, due to the weak nuclear force, where a neutron transforms into a proton, an electron and an antineutrino.
This is where quantum field theory explains things that quantum mechanics cannot explain on its own. So what is quantum field theory? QFT a mathematical framework that combines classical field theory, special relativity, and quantum mechanics There is a field for every particle of the standard model.
All of these fields extend out in all of spacetime. The fields are always there and exist everywhere including inside your body. Although they exist everywhere and you can’t see them, they are not nothing. They are teeming with virtual particles. These are particle-antiparticle pairs that get created and destroyed constantly.
We can visualize these fields as a kind of ocean. Just like the ocean always has some turbulence, the fields always have a kind of turbulence even in their ground state of minimal energy. This turbulence is due to virtual particle creation and annihilation. In these turbulent seas, if there is enough energy, a larger wave can be created which CAN be measured. These are the real particles.
Energy can be transferred between two fields via a mediating boson field. This is considered an interaction or a force. Matter particles can’t interact on their own without a mediating boson.
So while in quantum mechanics there is no way for the neutron to split its energy into 3 different particles - a proton, electron and antineutrino, in quantum field theory this can be done via energy exchange between the fields. Although the number of particles may change, the total energy is always conserved. In other words, the energy of the fields is the same before and after the energy exchange. So by having quantum fields we can mathematically account for and model creation and annihilation of particles, as well as the mechanism of force exchange.
#quantumfieldtheory
#QFT
The icing on the cake is that the theory is fully relativistic, and free of causality violations. But even this modification of quantum mechanics is not perfect. For example, QFT is still missing gravity. We do not have a quantum field theory for gravity. So even QFT which is extremely accurate for the forces and particles we know of in the standard model, remains as yet incomplete.
Best brief QFT intro I've come across!
Minimum
So can this quantum field interaction account for entropy?
Love these vids and yours Sabine!!
If Sabine says this, I have to watch this video in every detail .
Sabine your videos are amazing the same way!
My physics teacher once asked me where my home work was. I told him it was part of a home work field. With my home work popping in and out of existence almost instantaneously. And there always being an uncertainty of where the home work actually is. He laughed, and I got off easy that time.
😂
The lucidity of your presentation and explanations makes what appears complex simpler to understand. Much appreciated!
agreed !
He would make a good used car salesman, able to convince the gullible of any nonsense. Which this all is.
@@L2p2 Why is it nonsense?
@@70AD-user45 did I say it is ?
Many real science explainers and demonstrators on youtube are excellent: Sabine, Sean Carroll, Don Lincoln, many others, and especially this channel should have several million subscribers. Arvin is a superb explainer with team behind him. This is like Feynman brought back to life. Not a single filler word and each thought leads to the next. And without silly sound effects. Superb.
L l Q
Meanwhile a bunch of wooo space is cool! channels with info from wiki have millions of views.
filler words, almost instantaneously, the fields are everywhere (fields are planes/plains/2d surfaces of anything. if they are planes that mean, no 3rd dimension). if red fields are everywhere then that implies all fields are everywhere. greens, blues, yellows are everywhere. if everything is everywhere then any one of these particles could never be detected. they are part of everything else. but you say you can be observed. that is like saying adding colored dye to a clear glass of water, the dye goes everywhere. And I don't believe solutions like this decay and become an area of clear water and an area of pure dye. All this standard and quantum stuff could be true but the illustrations don't seem to match the storyo.
Dude, this explanation is probably the best I have ever seen for QFT. Thank you
yes sir !
Agreed : )
What's blowing my mind is this video is basically particles explaining to other particles how particles work.
Hey Arvin, after binging all of your video's I have become so increadibly intersted in physics, you are one of the main reasons for me choosing to study physics. So I want to thank you for making seemingly impossible to understand subjects intuitively availible to all of us :)
Great to hear! Thank you. Welcome to the journey.
@Arvin Ash sir 🙏 I suggest you to read about Advait Vedant which is very similar in concept to QFT
LMFAO! You got tricked by a fraud! This guys actually pretty stupid.
Certainly changes the way I think about Matter and Energy and their complex interactions. Thanks Mr. Arvin.
As always, Arvin makes a highly complex concept really approachable and brings it closer to our limited minds. Thank you for that, every time you create a new video I watch it with confidence that I will be able to grasp the concept behind it. The only thing that I know I will be missing by the end is simply more on the subject. It's like a window to a new universe which is shortly opened for us.
Great thing about physicists like you is they can step aside from the math and actually explain whats going on. An oft overlooked aspects of explaining physics. I'm a physics teacher myself and I teach this way also.
Is it really possible to understand QFT/QM with maths? Even GR?
@creativesource3514 If you believe it is, it is.
@@bryanchambers1964 I'm a doctor. I was just asking as you are a physics teacher.
@@creativesource3514I understand the basics of how an internal combustion engine works, but I couldn’t design and build one. That’s kind of like understanding this stuff in principle versus calculating all the wavefunction madness
Beautifully described and edited video. This is a visualization that I have not seen before but it clicks so many pieces into place for me!
I can't wait until amplituhedrons get explained on this channel. You're so good at explaining!
What an amazing episode. Amazing visuals with outstanding explanation. 🙏
Did you eat your curry today my friend...
@@Sidionian yes bro 😀
These idiots are beliving it out now when our ancestors found it long time ago... Vasudhaiva Kutumbakam Whole world is one family 🥰
@uPtrade 😢
Qft most closer lord buddhas talks
With such an immaculate explaining method, we had no issues in understanding everything you explain to us ,, many thanks .
That's incredible that the fields extend in time as well as space. The best news I have heard in the 13 billion years I have existed. Well done man!
@uPtrade and fake reply
do you also believe in Santa Clause? You seem very gullible.
13.7 Billion* and honestly. We might be older.
@@shawnscientifica7784 Or that story might be all guesswork, as we don't KNOW what happened in the past. We make assumptions. We cant even agree what really happened in WW2. let alone millions of years ago.
@@shawnscientifica7784 I remember when it was about 12 billion+. Each new space telescope puts years on my life!
Another great video, Arvin! I also really appreciated your framework of using classical physics to "explain" electron behavior in an atom, and how that doesn't work, so it led to quantum mechanics. Like 99% of science communication is finding a way to make unintuitive concepts more intuitive for people, and I think using that historical parallel really does a great job of showing that we had a tool, it didn't work to explain this behavior, so we observed that behavior and it helped us create another tool, that then led us into that same situation again, and tada, QFT. Really well done.
Best visual explaination Arvin! QFT is beautiful and it shows us that at the smallest levels there is actually nothing. Just invisible fields.
I just found your channel two days ago and I love it so much! I’ve watched tons and tons of video but yours is simply one of the best I’ve come across so far, you did a very wonderful job sir 👍🏻👍🏻👍🏻 Also, I’ve never seen a more beautiful segue to the sponsor bit of the video, very well done ♥️
Thank you so much!!
WOW WOW Mr Ash, Thank you for this videos! Every new video gets better and better! As i said before, i'm nowhere near of a physicist, but for the first time i feel i understand a little bit QFT! Please i hope people make your videos more popular and that you get to 1M subscribers soon! Thank you and your team!
By far the best presentation of advanced topics I have yet to find. What a great job you do Arvin.
What a great visual depiction and explanation. It's people like you who make this world a better place....well for me it is. Thank you! I am interested to know how the fields are interconnected with all time and every thing.
Arvin Ash's videos make complex concepts so appealing and intuitive. Highly recommend this channel. Thanks so much Arvin
i second that !
i use this and pbs space time to get familiar with last science thoughts.
Arvin, you are astonishingly good at what you do. Please never stop. Thank you.
the best visual demonstration and explanations of QFT I have seen. thank you.
This is a subject that I've been struggling to get my head around. This video really helped. Thank you!
Thanks Arvin, I really enjoyed this one. The interactions between fields has never looked clearer to me. An anti-neutrino is just like a neutrino, except that the field's value "points the other way"... assuming that's accurate, it's a really intuitive way to think about it and helps a great deal.
Glad it was helpful! it's an approximate illustration.
You are becoming my favorite over PBS spacetime!!! don’t get me wrong. I still love that show but I feel like your last couple videos, you have given me “aha" moments, both on explaining in a layman friendly way, but also love how are you tie it together with the we are all one thing!!! I always wondered if it was just me or if there were people who understood it much better than me who also got the feeling that the things we learn from quotum mechanics seem to jive with a lot of the eastern philosophy about we are one… you are the universe… etc
They do. And not just eastern philosophy. It reaches a point where you become inclined to listen and consider what older cultures have said. We tend to think the old ones couldn't possibly have any accurate concept of the fundamentals of reality, but ultimately science is only describing something that already exists, in order to understand it in a new way, but(apparently) it's not the only way. After all, there are many paths to a single destination. The curious part is how they figured some of these things out without science. Makes you wonder about the other things they've said that we haven't figured out or linked scientifically.
Thanks Arvin ! helps clarify the context. QCD, QFT, QM all very confusing concepts but you have clarified !
as someone who just learns physics from tv, youtube and podcasts, qft has always been so confusing, magical and mystical but this video has helped me massively understand how it works
Amazing. Ill Watch ithis as much as necessary for complete understanding. TY very much Arvin !
Thanksssssss Arvin sir! This is by far the best explanation of the boson(animation of matter interaction) I've ever come across!
The most beautiful explanation of QFT I ever seen! You are really awsome Arvin!
Could probably be that I finally understood this thing - on a basic level : ) Thanks for this great explanation!
This is another excellent video! I appreciate your honesty in what can and cannot be explained… you are a true scientist.
Best video on QFT ever! The animations make it so so easy to understand!! 👍🏻👍🏻
Perect. Whenever I don't understand something, I come to Arvin Ash!
12:40 - When he said “I find this to be beautiful” - his smile was one of the most beautiful, meaningful things I’ve ever seen. Incredible theory and incredible presentation!! ❤
Arvin, you are such a brilliant teacher. Love this.
sickest animation i've seen, sound fx are a bonus. amazing work
This is a really great illustration. IT drives home in a simple way that many of the "mysteries" of QM are solved by using QFT.
Great graphics for the interaction and mediation between fields! Thanks again for the great content! See you in the next video, my friend!
11:44 Is exactly the reason I'm so into science and philosophy, to get that interconnectedness to all people snd things!🎉 #Spreadtheknowledge
The imagery and visuals have helped me so much in understanding this complex topic, I love your final thoughts, they are poetic.
Arvin you are such a BRILLIANT teacher! Thank you for making and posting these here
This presentation made sense to me FINALLY! So cool to "get it" understood after much deliberation, studying, confusion, etc. Thank you Arvin. My world makes so much more sense . Love you too...
Wonderful! Thank you for the compliment.
Arvin as always a magnificent explanation.🎉
Gonna share this to a friend of mine. Thanks Arv!
Great presentation mi fren. You have a great way of simplifying complex concepts. Thanks
Mr Ash indeed, this was a beautiful explanation, finally our scientists getting the point, I truly enjoyed this explanation.
This particular episode is excellent. It reveals some issues with QM and Standard Model etc that are often not discussed. Refreshing
Got a subscription out of me, one of the best I’ve seen on topic. Great work. Keep it coming.
You are the best teacher on u-tube. Thanks for sharing your knowledge and expertise with us. All the best to you my friend.
7:54 maybe there are a finite number of particle-anti-particle pairs in the universe and since they are together, they are undetectable but if you apply enough force, you can separate them.
thats how higgs boson was discovered right
PLEASE do a video on Quantized Inertia by Dr. Mike McCulloch. It explains galaxy rotation WITHOUT the need for Dark Matter (mathematical fudge factor). It elegantly combines Unruh Radiation, Casimir Force, and Rindler Horizons to explain inertia.
I second that
Yeah another weird idea. Inertia caused by Unruh radiation with a temperature even lower than hawking radiation. And how would it explain the usual roadblocks to non-Newtonian models such as baryon-acoustic-oscillations, bullet cluster, dark energy and the large scale structure of the universe and how would even higher accelerations (eg. above 1000 times higher in the CMB era) fit with observation?
Excellent. Written Statements according to the lecture and views are exceptional indeed.Expecting more and more videos.Thanks.
i don't quite understand the whole explanation. But somehow, feel the conclusion.
Very nice episode Arvin :-) My opinion is that the concept of separateness may be the most misleading concept we have in physics. It shapes our intuition and the questions we ask.
We are extensions of each other in the most fundamental way. Slime-moldishy.
Thank you for bringing up a holistic perspective in the end❤
Arvin Ash explains and visualizes things to the general public better than anyone I've come across. What a service to humanity, bravo!
Incredible explanation of QFT. I find myself trying to imagine how all those fields overlap and exist at every pinpoint spot in space....deeper dimensions of the super small make my head hurt but I still want to have it make classical sense.
I totally agree, at what point does the quantum become classical, mad, I have a hard time with this thought.
Arvin can you show us how matter and energy stay together in these fields on a macro level. Like, how does our bodies stay together in the same way without morphing and changing within these fields. And if two or more people are standing together how would it look in the fields. I hope i explained myself well enough🤓
There is no matter. It's all energy.
Lots and lots of balancing of electromagnetic forces. Atoms repel, link together in molecular bonds, slide around, and influence each other. The reason you and everything in the universe doesn't just fall apart is because all the particles, atoms, molecules in your body interlock and attract and repel and move around in a way that creates what we perceive as solid structure. Think of how a pile of sand doesn't just collapse and roll away like a pile of marbles might, or how a bunch of tangled-up pasta is hard to untangle if it doesn't have any sauce. They're made of unconnected bits, but the pieces interact in a way that gives them shape.
@@ArvinAsh I have had the same question as "Dray", but I can never get an answer that is explanatory. Can you expand on "it's all energy"? - this does not really answer the question in an understandable way (at least for me). So if we think we see matter, this is just a trick that our brain is playing on us? Or is it a matter of semantics? What we ordinarily call "matter" is perhaps "really" energy, but it is identifiable to us as "matter", distinct from what we would perceive as "energy". I think the real test of that theory (or at least of one's belief in it) is to not hesitate to commit suicide. That would just be the rearrangement of energy fluctuations etc in a quantum field.
Matter “is” energy basically
Matter doesn’t really matter. Strawberry fields forever!
Incredible! Lovely explanation and first introduction to this channel.
Great video! Watching the modeling of these standard model fields, or fields with energy excitations, can’t help but notice and consider the bending of the space. Like what gravity does.
Another wonderful learning tool! Thank you Professor Ash. At 10:01, you say that the energy transfers between particle fields happen almost immediately. Do we know how fast? Perhaps c, or the same speed at which entangled particles interact, or some other speed? I would love to see what these quantum field animations look like while collapsing the shared wave function of entangled particles 🙏
Yes, we can calculate how fast. Look up the Energy and time derivation of the Heisenberg Uncertainty Principle.
@@ArvinAsh can you explain the mass gap problem? it's one of the 7 millineum problems. I'm 13 and interested in physic but it's kinda hard to understand
Sabine and you are producing best quality content on physics on youtube. Love you guys.
Let me recommend you: PBS Space-time
@@metruna he is doing great as well. But he is on more technical side. Whenever I need to get deeper insight I watch his videos. Thanks bro.
I honestly love your videos. Thank you for all of it!
What a beautiful explanation! This too, is my favorite theory and has been since 2017 when I first learned about it
The best explanation about quantum field theory I heard so far!
This was a great explanation arvin 👍 What you explain at the end about everything being connected is what it feels like taking lsd or psilocybin. Maybe the path to discovering whats next is in our subconscious....to see/feel the unseen. Enough of my hippy rant, thank you for the video and the great visuals 😃
I agree fully. Theres gotta be a connection with the brain and the universe.
💖
Before I learned physics, I saw visions on mushrooms. After learning physics, I'm about 80% sure what I saw was something like QFT. Only a few things were different
After watching over a dozen QFT videos, I think I finally got a picture 🎉Thank you!
The connection is beautiful. We should all feel a sense of this and seek harmony. Well said!
when there are quantized energy levels in wich the fields can be exited, how can the Energy distribute into a wave funktion? ( I know, its just the probability to find the quanta of exitement at the points in space time, but the wave ofprobability clearly interacts with itself)
when energy is quantised, there is a specific value in which the energy distribution is allowed.. they borrow the energy created in the vaccume as stated in the video, but the total energy borrowed is so less that it is considered negligible but its there.... and as we know from Einstein energy mass equation it can be converted into one form from another but the total energy remains the same or elese it would conflict with the energy conservation law.In simpl word, otherwise it requires advance mathematics to explain it in detail... of how thery are exchanged and trust me you'll hate it, its really long and hard, it will give you nightmare, also you might have heard of the particle dual nature, its all from there
QFT doesn't really have wave functions, it has field operators. Most QFT calculations consider non-interacting initial and final states being linked by an interaction matrix (called the S-matrix). Also: the wave function is not just the probability of finding a quanta at a point in spacetime. QM is non-relativistic, so time is just a parameter, so its "in space". The schrodinger eq then describes the time evolution of the system. But the point is the wave function is a complex (as in real + imaginary parts) probability _amplitude_ ....very different from its square: the prob. of finding a quant at "x".
Arvin! What is the spacetime itself made of? Thats i ve never seen anyone talking about. Please make a video about that . 🙏
Surface of a hypersphere. Huge hypersphere..
That's a good question. Other than containing various fields, the actual makeup is not really understood. According to Loop Quantum Gravity, it is quantized. See my videos on Loop Quantum Gravity. But this is not a universally accepted concept.
What about the theory of entanglement forming the fabric of space time itself. Is this something you can delve into?
@@ArvinAsh If spacetime contains the various fields, and gravity is the curvature of spacetime, wouldn't the fields also be curved due to spacetime's curvature? Doesn't that incorporate gravity into QFT? Or is the curvature not big enough to be relevant at the scale QFT operates in?
@@marishkagrayson Yes, it's an interesting concept.
Very brief, informative and extraordinarily helpful. Thank You! So many clips on science are far too wordy and unfocused. I don’t have enough time to struggle through them. Yours was right to the point described: PERFECT!!
I absolutely love the standard model, simple but complex, just genius.
I did too. Right up until they told me to ignore gravity.
@@mitch_the_-itch Who told you that?
Please make a detailed video on string theory 🙏🙏🙏
I made two: kzhead.info/sun/Zs6EgK6ZZJhplok/bejne.html kzhead.info/sun/d9R_nNWbhKmeZY0/bejne.html
Wow, the best ever lecture on QFT!
Beautiful, I believe, might be an understatement. I find this magical and peaceful. Thanks
Loved this video. Narrator spoke easily and confidently and made me feel like I'm not stupid for 14 minutes. Thumbs up number twenty-thousand-one!
I think you have that backwards -- it is from fields to particles 🤷🏽♂️ ijs
Actually it's all fields. There are no particles. But our understanding historically has gone from particles to fields.
@@ArvinAsh didnt mean to throw shade and you are right. QFT is great. It makes it all make sense. I sucked at chemistry until I got to QED. Then QFT took me to the next level. Chemistry is sill not my strongest suit but I enjoy how QFT makes everything waves... i think love operates kind of the same way. Though that would be a different realm of discussion.
Such a great video!! So QFT simplified in context of this video is just multilayered unlimited unified field playing, explaining itself to itself about how itself explains itself constantly with energy conserved. If energy is constant maybe in "bigger" smaller scale energy is just another layer of QFT.
Wow. Excellent explanation of the practically impossible to comprehend! Thankyou.
I love this. So clear! Thank you!
Very well explained and Insightful! thank you
Arvin is getting better and better in his presentations. Well done.
Z przyjemnością obejrzałem świetny materiał filmowy. Dziękuję też za tłumaczenie.
Thanks for making this video! I enjoyed watching it
I now understand all of qft thanks so much again arvin ash😊👍🏻!!!
I’ve watched a lot of videos on quantum, but this is absolutely, hands-down, the very best.
Thanks ArvinAsh for another brilliant narrative on the subject
Sir, i will always be grateful of your contribution, thank you.
Thanks for the excellent view of such a complex subject.!
2:56 I like how you have used blue color for positive sign and red for negative))
What a great video!!! What a beautiful conclusion!!!
Beautiful animated explanation of QFT dynamics, going beyond the Feynman diagrams. Maybe gravity can be explained some day as fractal extrapolations of these quantum fields...
Took me an hr to finish this. Kept 'rewinding' till I was sure I understood a modicum of the concept before I advanced. 💜
Thank you Arvin, you are such a brilliant man.
You are the best physics teacher on the Internet by far you make everything so clear to the lay person so thank you very much and cheers!
Thank you and your team for excellent work!
Excellent explanation!! Well done Arvin!!