Quantum Field Theory visualized 

Hi sciclic. Thank you very much for this beautiful illustration. I wonder if you can recommend some textbooks on this subject?

Is so obvious u go to cambridge\oxford. You’re over pronouncing the words.. wtf? Is just try hard and overly preppy. Alienating. Unless u think ur a cut above other ppl because ur clever and/or go to a good school. Not a bad thing, good studies get done at these places but stay human and don’t think ur better than other ppl because ur part of some elite club that speak like they have a silver spoon up their arse

@Hugos Thar Actually it's not me speaking in the videos, I am French and my English accent is terrible so I asked a friend who kindly accepted to record his voice. Octave is doing a great job helping me translate the videos

@@ScienceClicEN yes you are correct and I’m just angry. That sounds sarcastic but I promise it’s not. Lol sorry. The way he said v-A-ries, as if the e had no effect on the a, reminded me of things not worth mentioning, but made me angry and caused me to react with vitriol, for which I apologise. Maybe the manner in which I’m saying this makes it seem disingenuous, but it is the exact same reason why I was angered by the seemingly arrogant mispronunciation of certain words. It is however, as you correctly state my ones accent is not something to hold against someone. Not to mention a separate issue to the content of the video which I do actually value; so unsure why I let this negativity cloud my vision

@@ScienceClicEN I think the English sounds pretty normal to me - so your friend did a good job. One or two “scientific” words to me are pronounced a bit odd with emphasis on the wrong syllable like “annihilate” or “temporal” - Other that that pretty normal. I did a B.Sc in Physics 30 years ago but became a geophysicist professionally - so I’ve long forgotten the maths but it’s really great to see the animations you are doing. I particularly like the space time animation you did in another video - I’ve always struggled with the rubber sheet analogy.

I know, this is a wonderful lucid explanation. I've watched videos where famous physicists talked about spinors and I was left feeling even more perplexed.

@@bobbobson6867 Can you do even a little better then?? Sort of.

Just what I thought. Also just how virtual particle interactions forge the paths of particles. Heard lots about Feynman diagrams and sum over all paths but not seen those so nicely intuitively linked before.

It lacks an explanation of what the hell to turn the universe around a particle for at all.

@@mroygl So you can determine their spin.

Try speaking as a toad. It will better suit you.

lmho - this is just nice graphics but nothing more...

@@andreyrushchenko2378 i would love to see your explanation then 👍🏽 Is it possible to see or hear it online?

I think they have not posed the questions that divide QM from GRT. Maybe here is a bit of a revolutionary idea about the Electron ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-1PD3uxHyhuY.html

It's an extraordinarily confused explanation of QFT, illegitimately mixing together bits from canonical quantization and Feynman's path integral, as well as interpreting Feynman diagrams as real field configurations when in reality virtual particles are off-shell. Philosophically it's wrong too, since it forgets that as in every quantum process all you get at the end are probabilities for the various measurements, whereas what was presented here gives the impression of something like a Fourier sum just giving classical physics. I have no idea what a layperson would get from watching this but it wouldn't look much like what physicists do when they do QFT.

Exactly! I don't speak Greek. But, I can look at their graphs and animations and write my own that results in the same conclusions.

@@MuffinMan87 Greek? Its an english voice?

@@bas_ee Greek is the language of physics. I don't know what most of their letters are called. It had nothing to do with the narrator's voice.

Eloquent, and elegant. Even if you’ve never had opportunity to mess around with a guitar, you can apply it to a speaker just as well (for all the bass-heads out there). I’m relatively certain that everyone has seen a speaker vibrate at some point? That’s probably naive on my part because some places just have different instruments due to culture and geography.

right??? like it made so much sense

I play guitar and Didgeridoo simultaneously.. I've gone into what my people the biripi Dunghutti of Australia call the dreaming...a continuous timeless place of creation ... The analogue of the vibrating strings and all the frequencies coming together to create the actual sounds is an amazing interpretation... Because it allows you to see it from now of a creator perspective and even ask .. "who is playing the guitar"? ...or what lol

that same visualisation can tell us why instruments sound different playing the same notes, when they are of course only emitting a series of sine waves at similar. frequencies. The dominant sine waves in that series will be harmonics of the intended/heard note: eg heard note at 300Hz: 2nd harmonic at 600Hz, 3rd at 1200Hz, etc. A particular guitar E-note string may have the root, 3rd, 4th and 12th harmonic at the largest amplitudes, whereas a violin E-note string may have root, 3rd, 10th and 15th. This simple difference in the combination of the harmonics is what determines the timbre and therefore the signature sound of one instrument compared to another. It’s why speaker cones can recreate every instrument- they just emit the right combination of sin waves at the right amplitudes.

this analogy doesn't work for me. it does not explain the principle of least action. the harmonic vibrations of a string do not "collapse" to a single frequency, but exist completely independently, robust under measurement. it's only in human auditory perception that these overtones "collapse" to a single timbre.

I think it makes sense if always wondered how the world works

You nailed it.

That's just your brain's pattern recognition associating the boxes around the 9:30 mark to military insignia badges like chevron patterns.

@@BasiliskInTheSky Happy octopus

@@brandonm9579 I don’t understand what this has to do with the content of this Video?

What scares you the most, quarks or electrons or something else? :-)

As long as you don't think about vacuum decay you're fine.

@@LouSaydus some eldrich stuff

@@LouSaydus i feel like we're more likely to die from a rogue black hole then vacuum decay

@@nobodyinparticular968 don't worry, vacuum decay or black hole is nothing in comparison with our reckless stupidity. We will destroy ourselves I bet 🤣

I agree!

Just ask me what you didn't understand maybe I can help (just don't ask me about energy quantinization I'm still learning about that)

@@DanoshTech I think I got lost when he started talking about how the spins are "abstract mathematical ideas". The way I understood it, in an extremely simplified way, is that quantum field theory is essentially a way of modeling a universe using just pure math that happens to describe our actual reality. I think it'd be useful if he described how a specific spin (or combination of spins) is meant to symbolize an actual particle. That's what I got out of it at least: particles are just complex combinations of spins, whatever spins actually are meant to be, I'm still kinda lost on. I also got lost around 4:45. What is that y-shape supposed to represent? Is it two particles combining into one? I think it's also fair to advice that I'm no physicist or anything. I'm just a curious teen that's trying to learn more about the world. I admit that I don't understand these concepts the way they're meant to, these are just helpful visualizations that'll help me when I actually need to tackle these concepts eventually. I'm a very visual thinker, it helps me to imagine things in this way. I understand that when you get to such small scales the concept of visuals and distances kind of breaks down, and imagining things visually is kind of useless, things tend to get more mathematical and abstract. Still, having some sort of visualization, even if somewhat inaccurate, helps my brain wrap itself around weird concepts like this.

​@@qwertydavid8070 I guess in 4:45 author just wanted to illustrate the conservation of momentum. So yes, basically two particles (doesn't matter which) with opposite values of momentum components along the horizontal axis glue to each other and thus their opposite components of momentum just neutralize each other

Just keep watching these videos, from different authors too, supplemented by books and other material. This is not a subject which could be understood from a single video, even if it gas the best explanation ever.

Check out Science Asylum, that's the other channel that helps these types of things click for me in the way this one does.

@@jaredf6205 I just found that channel, finally understood tensors and the field tensor for my gr class after watch just one video there.

And I just found this channel only a couple of days ago already being subbed to both of those channels for years, it's SO good!!

I can’t stand Science Asylum host and the presentation, it’s a shame because the information is very good

@@tophan5146 Bit marmite, I guess?

Thank you very much ! Took a lot of time to find good visualizations

@@ScienceClicEN Did you make the visualizations yourself? What tools did you use? I'm always trying to learn how visualizations that I admire are constructed.

@@rodvanmeter517 i find many illustrations made in Mathematica are well done.

What is QFT? Quantum Fuck That?

Agreed - the animations here are superb.

thats an awesome quote

We’ll critiqued ❤

This also blew my mind.

This also blew my mind

I had to pause and think through exactly that thought. Blew my mind.

🙀 mind blown

no he did not

Thanks glad you liked it !

I believe it's the pauses. They give room to comprehend the explanations

It's extremely impressive!

This is EXACTLY why I like these videos. concepts are explained visually, pacing is slow enough for actually grasping the information presented, while being fast enough that you don't lose the thread. The background music track helps with this IMMENSLY. Maybe it's just me but that + speaking speed + information pace in a great balance is probably the most important factor when educating.

ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-qfi0vaBMnTA.html

Glad you liked it ! I've just finished my Master's and same as you, when I was studying I looked online hoping to find intuitive visualizations, but couldn't find anything convincing

im a physicis student too but i only study on youtube

This explanation is fine for a more casual viewer but if you're actually learning physics I'd advise you to be cautious of it. 5-second long snippets of this video make sense in isolation, but they don't really form a cohesive whole -- it's as if someone mixed three different jigsaw puzzles of the Eiffel tower together and presented various bits of it as if they formed a single picture. There are pieces of several different 'perspectives' of QFT in this video, but they're not all true at once -- you have to pick one or the other. For example, the author says that to turn a classical object into a quantum object you "allow it to adopt several positions at the same time, with more or less probability" (which isn't quite right but it's a common enough so let's leave it aside for now). Then it is asserted that to turn a classical field into a quantum field 'we allow it to adopt several configurations'. The trouble here is that the former is describing so-called canonical quantum mechanics -- wavefunctions and so on -- whereas the latter is really describing Feynman's path integral formulation. The correct comparison should be between particles taking all paths between two points A and B, and fields taking all (time-dependent) configurations connecting configurations A and B. It's a subtle difference but an important one -- when doing canonical quantum field theory one doesn't deal with superpositions over classical configurations, but rather with superpositions of definite particle number -- there's an uncertainty relation between particle number and field intensity, so there's a possibility of confusion with the next point as well, since the presentation suggests that particles are associated with the fields being in a given classical-looking configuration but that is very much not the case. Anyway, the point is, if you already know QFT it's easy to sort out these various jigsaw pieces from one another and pick out the kernels of truth in the presentation, but if you're still learning you run the risk of ending more confused than when you started. I don't mean any disrespect to the creator of this video -- it's of course a laudable effort supported with really well-done visualizations. QFT is one of the hardest subjects in all of physics so it's unsurprising that it's hard to convey it in a way that's both accurate and understandable, and I think on average the video is useful for a layperson who wants to have a better idea of how this works. But if you're serious about learning QFT you need a presentation that perhaps sacrifices a little understandability for accuracy.

@@isodoubIet I completely agree. I'm studying for my QFT exam and I felt that the video hopped and skipped around all the important parts of my module. I felt so confused by this video I didn't know whether it's actually correct or not lol. At the very least, it's very pretty.

Truth is -- QFT is complicated. There is just no way to put it simply. While the visualisation is well-made indeed (thumbs up to the author), it is unfortunately not rigorous and should not be regarded as such. Vanilla QM has quite a simple mathematical apparatus, and yet its mapping to the real world holds questions which after a century nobody can fully answer. And in case of QFT *both* of the aspects are complicated.

Spin and vibration have similar effects. You can only spin a solid so fast. Plasma can be vibrated and accelerated to create cool quantum vacuum.

Why the fuck dont you nutthuggers timestamp your comments?

But it is still just all made up, it doesn't mean a thing, you people just suck this crap up and tell these people how clever they are.95% of the people watching has no idea what this guy is talking about

But it is still just all made up, it doesn't mean a thing, you people just suck this crap up and tell these people how clever they are. 98% of the people watching have no idea what this guy is talking about. Watch it again and tell me you know exactly what he is talking about, all these wonderful particles with their wonderful names and then there is the anti matter

​@robertthomason8905, just keep believing it, I am sure you knew exactly what you just said

And this is why I read comments before commenting. Came to say the same. Clearly!

LOL.... damn good one! hey, this comment should have thousands of likes... here you have mine, just one is all I can give unfortunately :)

Damn.

what does this mean..??

I salute you for making me feel even more stupid

Do you like collard greens??.🤔

@@lawoull.6581 Right here...👋

@@lawoull.6581 I like color green…does that count? 😆

@@rachelnyn5543 ...it's a vast universe....you're in.. yesss

I wish you a lot of success in your education, it's good to see younger people seriously interested in this stuff.

Very glad this can help you ! Good luck in your work, QFT is very interesting

Hi Lorenzo I am a novice. But can understand maths ans enjoys. Please recommend a book on QFT, the one I have is too complicated for me. I have Introduction to QFT by Peskin and Schroeder

@@thesciencehinduby the lecture notes by David tong are pretty good, also free :)

@@thesciencehinduby Peskin in Schroeder give by far the best substantial introduction to QFT available

@@youtubesucks1885 Peskin is good if you already know qft

Thanks ! Glad you liked it :)

Thank you very much for the compliment 🙏 I am very glad you like it. Not yet no but I might do one in the future. Basically I draw the images with Photoshop, and then animate them in 2D / 3D using After Effects. With time I've learned a few tricks to optimize my workflow so I can produce better looking results

Very very impressive!

@@ScienceClicEN You are amazing

@@ScienceClicEN I would recommend learning Blender

Yes I use Blender for some projects, it's great! (I used Maya before but switched to Blender a year ago), but for these videos as it's mainly 2D I am more familiar with AE

12:30

Yes! Especially after I just learned about the nature of overtones which is you hearing the individual sin waves that make up the superposition and learning that sythisisers are just computers that synthesize sin waves. 🤯

But, what if the guitar has a vibrato ?

@@pascalfragnoud2846 any example video? so that i can see and reply accordingly?

@@yash1152 Oh, that was just a joke ! But alright, I'll play the game. The part where the strings meet the body of a guitar is called the bridge. There are many types of bridge, but mainly we can split them in two categories: fixed bridges, and floating bridges. What is special about a floating bridge is that you can move it, usually with a thin metal bar, which has the effect of changing the length of the string ever so slightly. Changing the length of a string will in turn change the frequency at which it vibrates, and thus change the note. Floating bridges have many names, a familiar one being vibrato (which may be confusing, as this word is also used for a different albeit not totally unrelated thing). The typical vibrato is the one used by Hendrix for the famous diving bomb effect. You can see one in use by Jeff Beck here (You can see the vibrato bar pretty clearly around 20 seconds, and he uses it regularly though the whole video, or even through his whole career) : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-nQDjSGnmYBI.html If you type whammy bar in youtube, you'll find a thousand videos showing exactly what I was talking about. I personally don't use them much, but it's a quite fun little thing !

Thank you that helps a lot 🙏

I'm quickly done with the sharing...

I’m also gonna share it with friends who are not into this stuff bc maybe they will be after watching this

@Carl Andren Because it's allowed. On macro-scale, you what is observed is the summed result of all possible scenarios. In that sum, all possible scenarios have to be considered: What if 1 photon is emitted, what if 2 are emitted (and how), and so on. Scenarios with multiple chained interactions at once are less likely, so they contribute less to the final result, but just from probability sooner or later the two (resting) electrons are likely to exchange a photon now and then, w hich makes them move away from each other. Because it's allowed, because it's possible, it will happen sooner or later.

@@Owlrrex Correct. It's an average of a billion zillion random microscopic movements and exchanges. For instance, at the molecular level, every oxygen molecule in a canister is moving in a random direction. But back yourself out to the canister level, and the average interactions are so consistent and predictable, they follow the Ideal Gas Law. Order from chaos.

@@protorhinocerator142 Great example.

So the act of emitting photons (from electrons) is the reason why electrons repel each other? And is there a similar reason why positive charges repel??

@@Owlrrex So is this why negative charges in general repel, because of photon emission? Does this apply to positive charges too?

A fitting review, indeed

You will enjoy then listening to Sean Carroll; he has a Patreon account which is the best way to expand one’s brain horizons.

The best analogy for me is the deck of cards analogy. Imagine a king of hearts. It has two heads, one on either side. You have to rotate the card 180 degrees for there to still be a head facing up. Therefore it’s spin is 2. Imagine a ace of spades. You have to rotate it 360 degrees so that it is facing upright again, because it is not symmetrical. Therefore it’s spin is 1. I hope this makes sense!

​@@darthnihilus4074 yeah, same thing with vectors too (as shown in the video - 3:45) - but yeah, urs one is more layman. and as with most things, the mathematical description requires less words but that's somewhat compensated by the requirement of more background info lol.

@@darthnihilus4074 that's because the rotational symmetry is given by 2*pi/spin

Yeah I watched it on 0.5x playback speed

hello, so you understand some of what he said or almost evreything he say, yes i know a year later,are you still there?, this is very interesting anyway, the things we now days can see and understand from the micro world

@@loroverde1621 just little bit

@@Kosmologi-Indonesia same thing here with me, but curiosity, AND. SEARCH,NOT FOR THE TRUTH, rader than just a better understandig,all the things, that i have beèn wondering to understend, since i was born, just like you or anybodyelse whit the desire to learn how things work in the universe, before i leave this world = this life,,and ,off course, this body off mine. PS, if i play with the words ,y shall say, this body off mind,

Thanks ! Indeed, spin is often presented as some weird quantum property, although in some sense it rather comes from relativity as a way to classify mathematical objects

@@ScienceClicEN I'd love to add Dutch subtitles to your video, but I don't seem to be able to do that

I strongly agree!

Well, @ least the most compact I've seen 'till now. Highly complex it comes along with optimized audio & videofeatures in order to be easily absorbed. & it rushes by with a pretty hard impact on me as well... @ least according to the impression it has left on me. Great stuff d(8)b... & THXxL, muck(8)

Thank you very much ! I will ;)

and ppl like me speed up to 1.5x lol... i am soo impatient i guess 😅😅😆

Its the taste of the apple that should blow your mind - "How" does taste get into it and into "you" unless your a superposition of thems ....?

@@elizabethwinsor5140 how: wow!

I am not, nor even close, to being a physicist. I just like reading and watching RU-vid videos about physics, relativity etc. But the 2 electrons being the same seemed logical to me. Along the lines of an electron is an electron is an electron. I have no scientific explanation to back that up. Just seemed intuitive to me.

reallyyyy?? to me, both are called same thing, "electron" in this case, because they have same properties. And 2 electrons - which by the name means that they have same property - WILL have same properties. if it had different properties, then they'd have different names lol. take how is anything named.... this is how it goes.

@@yash1152 circular reasoning

watching a youtube video is not studying. If you dont read a proper book on QFT you will never understand it.

@@Teo-uw7mh well, I agree with you that to watch a short video is not going to have the same result as reading a most likely very thick book. But if your point is that, in general, a video can not substitute a book, I disagree. Actually, nowadays I most commonly listen to audiobooks instead of reading them, or, I watch videos of complete courses recorded in a classroom, with famous professors like Feinmann, Susskind, and many others.