The First Quantum Field Theory

[@EugeneKhutoryansky]

Very nice job on the animation of the array of oscillating springs eight minutes into the video.

[@sam-bl5co]

Really I didn't understand your general relativity vedio .....I'm 14 yrs old....can u simplify it in another vedio....Ur graphics are stunning

[@pizzaman6999]

@@sam-bl5co .GR ain't something you would want to learn by animations only, just go for a good intro to modern physics book like nolan Or Arthur bieser

[@sam-bl5co]

@@pizzaman6999 tqq u

[@jack8n]

It wasnt animation

[@canadianatheist3578]

I missed it and saw your comment so I went back! Love it 🤣 thanks hahaha

[@davidt0504]

This is one of the only shows on youtube I consistently watch every new episode for. I have a BS in physics but none of my professors ever really "explained" these concepts beyond just how the math works.

[@colinshawhan8590]

Because they A) don't understand it or B) secretly hate that reality is this weird so they brush it under the rug, like, "Yah, this is weird but MAAAAAAAATTTTTTTTHHHHHHHHHH!!!!"

[@minhucovu6321]

They just don't really have the time, really

[@marcinna8553]

​@@colinshawhan8590 ???? You really think professors don't understand the subject, they brush it under the rug and rationalize it all by resorting to with math? That makes no sense. People go into physics because they are fascinated by it and good at it, not because they hate it and don't understand it. And math is the foundation by which we come to understand physical concepts. Since Galileo and Newton, it is how we have come to understand as much as we do. Here is what Richard Feymann has to say on the role of math in physics: "Mathematics is not just a language. Mathematics is a language plus reasoning. It's like a language plus logic. Mathematics is a tool for reasoning. It's, in fact, a big collection of the results of some person's careful thought and reasoning. By mathematics, it is possible to connect one statement to another."

[@u235u235u235]

you're admitting you didn't read your textbooks. cause the books clearly explain it unless you have a reading deficiency.

[@u235u235u235]

@@marcinna8553 i think mostly cause they're good at it and like getting recognition and positive feedback. ego is a positive motivator.

[@elgabacho73]

I don't understand 90% of what he is saying but I'm still watching. I'm hoping that I'll eventually understand it if I watch it enough times. :/

[@ireallyhatemakingupnamesfo1758]

I started in the same way, but now after about a year I've started to understand the stuff he says, I think I'm about 50% now, so there's hope ahead, stick with it!!!

[@richibucki]

Ben Martin the class is too hard :(

[@ronaldderooij1774]

Just take home that the universe is nothing more than a bunch of fields. Where there is a lot of concentrated energy, there is matter. Where there is a bit less energy, there is radiaton (including light). We humans see that as particles. Now one step deeper: When a few fields interact with each other (lots of energy in the quark field, gluon field, electromagnetic field together) you have matter in the form of an atom.

[@jjptech]

same

[@WestOfEarth]

Don't worry too much. There's a famous joke about understanding Quantum Mechanics. It goes something like this: "There are 10 physicists in the world who claim to fully understand quantum physics, and 8 of them are lying." This is the cutting edge of physics, so try not to be discouraged. Keep at it!

[@99bits46]

Paul Dirac was underrated

[@PeterMorganQF]

Salman Mehmood Nah, he just didn't like to talk about it.

[@DushyanthEdadasula]

That's because he wanted it to be that way

[@pauldirac808]

Feynman is my love child.

[@zes3813]

no such thing as xrate or not, doens't matter

[@1invag]

Dirac was famously an introvert. The mirror opposite to einstein

[@math.physics]

As an engineer who has always been passionate about math and physics, I was intrigued by modern physics, despite neither relativity nor quantum mechanics were part of any course syllabus at my university. I studied these subjects on the side and found them really inspiring, I would go as far as to say that they gave me a novel perspective on life itself. That prompted me to create some online courses on Udemy on Quantum Mechanics, Quantum Field Theory, special and General Relativity. It’s not my job of course, but I love talking about these topics while using some mathematics for “intuition”.

[@slevinchannel7589]

Its my (silly) hobby to spread education by recommending science-channell.

[@shahkarabbasi1224]

I m also I have completed my diploma in engineering and I also like it

[@k4frol]

LOVE the way you phrase some things: the math of QM "reflects" deep truths about the universe; QFT "describes" particles as vibrations in fields. You don't lead the audience to think that's truly (whatever that means) how the universe is, but that it's the best description we have. Masterful treading of an exceptionally fine line. Good stuff!

[@karanbirsingh1559]

<a href="#" class="seekto" data-time="227">3:47</a> "let's go quantum" . . That's when i lost him

[@andrewmiller5326]

Let's be honest, you'd lost comprehension at like 30 seconds

[@shanefoster2132]

"to do that we are gunna need another genious." pls be Feynman, pls be Feynman. "we're gunna need Richard Feynman." YES! "... and we're gunna need another episode of spacetime." NO!

[@zes3813]

wrgno such thing as yesx or neex or geniux or not, doesn't matter, cepitxux, think any nmw and aby be perfx

[@LuisSierra42]

@Zeppy UwU He stopped working

[@Semicon07]

@@zes3813 alt+f4 man, your brain encountered a stop error.

[@yamansanghavi]

Now I feel that PBS Space Time is back to life. Thank you so much for this quantum series. I love PBS Space Time

[@bgdavenport]

I am four years late to this discussion and totally enamoured by it. Thank you!

[@TheRestartPoint]

I'm amazed at how well this is explained, usually Quantum theory baffles me very quickly but I was able to appreciate this whole video, thanks!

[@kevinocta9716]

My FAVORITE youtube channel of ALL TIME!!! I love PBS Space Time! I will not have had my fill of this channel until literally EVERYTHING in the universe is explained one video at a time!

[@rixt53]

I'm not betting that I'll be around long enough that everything in the universe will be explained. The elusive TOE may well be generations away yet.

[@djschultz1970]

I had to read Nueromancer by William GIbson 7 times before i knew what it was about. Now I consider that casual light reading. Even though i still do not completely understand it I get enjoyment and new ideas, rather than stress, out of reading it again. Keep reading! it eventually works!

[@craigwall9536]

You read it seven times and you still can't _spell_ it. Wow.

[@bialek.online]

Another week of fine shower thoughts ahead of me. These recent Space Time episodes are hypno interesting. Good work!

[@searchiemusic]

<a href="#" class="seekto" data-time="218">3:38</a> as an audio engineer this sentence just completely rewired my brain i think

[@kedwardsTWO]

How the heck have I only just discovered this channel now? Love your work!

[@aliasgar2646]

next stop quantum gravity???

[@darkdevil905]

hopefully

[@gregmw]

Renomalization first. Have to tame those infinities Matt talked about with a path integral. Then there's Gell-Mann and the strong force, which tamed the particle zoo. You can get into string theory from there, as it started as a way to understand nucleons.

[@supreme84x]

Ali Asgar No. next stop is Quantum Chromodynamics (QCD). We are still quite away from Quantum gravity.

[@NuclearCraftMod]

Leonard Susskind moved from QED to QCD to the Electroweak theory/Higgs mechanism is his lectures. The same might happen on this channel.

[@supreme84x]

NuclearCraft Mod In school, they go qed, then qcd. We had to have qed and the Pauli principle before we could look at quarks and device color charge (Chromodynamics). So understanding the gluon, quark-antiquark pair and valance quarks is up next. Get ready to get your RGB on.

[@sokaries682]

Every episode seems like a christmas gift, love this series

[@1PKFilms]

this is so awesome! I am writing a paper for my a levels (you can do that if you want to in gemrany it's counted as an additional exam) and I choose which theories/rich symetrys are my subject and then you make a video about this which I need to understand anyways. Also you sooo motivated me to get started!

[@xmansemail177]

I think a lot of people would be interested to see what goes into making these fantastic videos. Filming, set, animations, script writers, bloopers. Thanks for the awesome content! :-)

[@xRawlins]

I wait in anticipation of the weekly Space Time video like it was a new episode of Game of Thrones. Such an awesome channel.

[@ThomasGutierrez]

Loved it! One note on the visualization in the video: the amplitudes of the quantum fields are not quantized in lockstep with the frequencies like a vibrating string in the graphic. A more careful analogy is akin to the single quantum simple harmonic oscillator like a mass on a spring, which has quantized energies (thus frequencies) but the spatial location of the oscillator is probabilistically fuzzy as described by its wave function. A quantum field is similar: the energy modes of the whole field are quantized (the particles), but the spatial shape of the field at each point is going to be probabilistic and thus quantum mechanically fuzzy (in rather non-intuitive ways as it turns out). However, normally it is the exchange of the energy quanta that are of interest, so the bizarre spatial shapes aren't (usually) of much use.

[@farlahore]

Wow the interactive video made the difficult concept understandable and the narrator did and excellent job making it simpler. simply amazing i would say. God bless u

[@TalysAlankil]

These have been my favorite episodes of yours so fat, hope you keep it going

[@LasseloH]

One dislike? Must be god. "Damn those fuckers are figuring that shit out too fast"

[@DissedRedEngie]

17 now... Maybe Hindus were right after all.

[@william41017]

A Very Disappointed Red Engineer if so we should expect about a million dislikes

[@william41017]

VTS -NL yeah, but for the sake of pbs I hope they're wrong

[@lewsheen7514]

Do you really think that everyone who watches these videos, and who also doesn't immediately understand everything conveyed therein, blames the *presenter*??? So you must have seen much better and easier to understand presentations about the nature of quantum fields... PLEASE share this gold-mine of lucidity with us!

[@william41017]

Lew Sheen what?????

[@johnregel]

Matt, I see what you did there with QED, getting ready for QCD. Well done Matt.

[@scottmuck]

You captured video from alternate quantum timelines! That's got to be worth a Nobel Prize.

[@ferdinandkraft857]

Congrats on another great video. Just one suggestion: an explanation on indistinguishable particles and how it is so different from classical physics.

[@doggonemess1]

Can anyone recommend a good quantum mechanic? Mine is ripping me off.

[@loser1234b]

Underrated coom net

[@waynelast1685]

He has to be outstanding in his field.

[@ferrreira]

doggonemess I can give you mine’s probability curve of addresses

[@daithiocinnsealach3173]

The problem is that as soon as a quantum mechanic looks at your car there's a 50% chance it will die on you.

[@realitynowassigned]

Mine either is or isnt. I wont know till i see his work

[@upandatom]

Great video :)

[@jamesbentonticer4706]

Yes it is. Love your videos too.

[@ThousandYearsInthySight]

Thank you for breaking down Quantum Field Theory in such a digestible way. It's a complex topic, and this really helped!

[@nejisamakage]

Thanks a lot for this video, very good pedagogy, continue your amazing work.

[@qaedtgh2091]

Wow, you explained this in such a way that I finally understand it . . . I'm just messing with you! I'm completely fucking lost.

[@freddylooger7320]

Not enough background information, cause they probably don't want the video's to be an hour long.

[@chalkchalkson5639]

it might help you to read/watch a bit about classical mechanics, if you understand Lagrange 2/Hamilton and Liousville who will see a lot of similarities and get a good grasp on the equations that way. Hamilton function becomes the Hamilton operator and a term is added, to give you Schrödinger And Liouville also stops tracking all the individual particles in a system. Difference being: there can be an intuitive understanding of these classical equations (And they can be extracted from QFT as well by setting the h bar to 0 and doing some other clever stuff)

[@gabemoser6493]

More like 4 hours X 10^5

[@eladpeleg745]

He is horrible at explaining! I think deep deep inside he's asleep

[@colinshawhan8590]

I'm with you. Basically, QED is really good. Take my word for it... This is why I am not a physicist. If I want to learn about something that is well established and understood, chances are I can find a WIKI article or lecture about it, read/watch enough of them and bingo! With the stuff this guy is talking about basically no one has a clue. Everyone gathers in their own little camps believing one theory or another and religion is born! It's good to know what the competing narratives are so when research comes out I can check 'em off the list, or not. But digging down into the nitty gritty of any one of these competing narratives is pointless. You're better off studying something which will bring home a nice paycheck, or go into plumbing! Plumbers do surprisingly well. Physicists, not so much. :(

[@hilariousharry1890]

This channel deserves more subs than pewdiepie!

[@daithiocinnsealach3173]

Fuh sho!

[@marcinna8553]

Yup, but that's the way the world works.

[@tanay6705]

nahh

[@Cloud-wl8lp]

Ok ceiling gang

[@tanay6705]

@@Cloud-wl8lp lol

[@charksey]

The introductory description of quantum mechanics is by far and away the best I've ever heard for any science principle. People often say things like "this is fact", "this is how the universe works", "the universe is math". This phrasing - "the mathematical description provided by quantum mechanics reflects deep truths about reality" - is perfect. Maybe the universe is math, maybe it's more complex, and this is the best approximation we have so far. We can use it to predict, explore, and refine. Love it.

[@colinshawhan8590]

Look for a video in which Carl Sagan talks about the fourth dimension with little flat people on 'flatland', and he reflects a cube onto flat world. That is exactly right, imo. We truly cannot conceive or directly grasp at the fundamental workings of reality, but we can see its shadows cast into our world and we can study them. Of course the results are counter-intuitive! They are distorted by our limited hominid perspective.

[@Sl1f3rDrag0n]

That was a genuine cliffhanger at the end of the episode. I recently graduated as a physics with planetary science undergrad and safe to say, GM was my weakest point. But at least I can continue learning through Space Time! Thank you!

[@GussTheRabbit]

very nice tax analogy. had a professor about 2 years ( maybe a year and a half) ago make a very similar lecture that made it all hit home. also, we need more than just another episode. we need a lifetime series.

[@josephlytle5453]

I love physics! I recently paid $75 to chat with a physics PhD for 30 min. I just have all these questions lol. I'd love to chat with this fellow sometime. I maybe could even help inspire a few interesting episodes haha. Thanks for all the great content!

[@christophercooney767]

Thank you for your videos. The De Broglie-Bohm interpretation seems interesting when combining the possibility of a ‘field-time’ curvature of quantum space (akin to a prior particle turbulence) that creates the observed wave effect.

[@MitkoG.]

Thanks...love this show!!! I can't wait till the next episode.

[@mrboredj]

I was going to go to sleep, but then I noticed a new Space Time video!!

[@Mormielo]

Yep, same here.

[@hodsonjosh400]

Dustan Jones same!

[@tiago0rag]

Exactly the same hahaha

[@JM-us3fr]

No time to sleep, the secrets of the universe are calling

[@dammitdanFTW]

you are all full of shit. this video has been up for like a day and a half. can't fool me

[@synonymous1079]

<a href="#" class="seekto" data-time="0">0:00</a> Wait, so Richard Feynman called the Great Courses Plus "the jewel of physics"?

[@LuisSierra42]

WTF yo

[@AImusicandart]

ROFL

[@unbutteredtoast6412]

The juul of physics

[@chemistryguy9679]

Maybe he meant to say "the joule of physics" ?

[@spencerlyon7087]

Lol

[@MakeMeThinkAgain]

I can't believe this series is getting even better. Can't wait for the Feynman. What you say here about field theory in general sounds quite similar (to me) to the way Dr. Kaku describes String theory. Are you going to get to that at some point in the future?

[@TheEmilmolnar3]

So I've been following you since quite a time now . I just wanted to say that im in love with all your videos , the way you explain them and of course the way that are animated. Also , i'd wanted you to epxplain or talk about the dimensionality in wich the Fields can afect the universe. Im asking if the fields exist in the hypersace (Space outside the 3 dimensions of space) and those have the observable efect in our 3 dimensions because of the oscilations

[@kayrosis5523]

So when I'm walking down the street, at this quantum field level, I'm some sort of "gust of wind" harmoniously moving in several dozen quantum fields occupying every point in space-time I pass through? Are the protons of my body moving down the street, or is it more like a pixel, which can give the illusion of movement but is actually just a pattern of changes in color and brightness?

[@GraysonGranda]

Erik S the way I understand it, it's more like you're a wave on the ocean. keeping in mind the fields aren't something MADE of anything, but more of just a useful mathematical model. Basically, the fields themselves don't technically move all that much relative to your motion, and their motion is more or less irrelevant, because you are part of the perturbations in the field, not a part of the field itself; much like how a wave on the middle of the ocean can be considered to be the perturbations of the ocean, but not actually a huge factor in manipulating the ocean itself. (I hope this helps somewhat)

[@garethdean6382]

No, there are a few important differences. A gust of wind and most other waesforms we're familiar with travel through a particulate medium like air or water, something made of smaller bits. Quantum fields aren't built like that, they're 'smooth' as far as we're aware. (This is important since other waveforms don't have an equivalent of light speed, a maximum speed water wave has a different velocity to different observers.) It's POSSIBLE the universe is a 'cellular automata', that is grainy or pixel-y on the smallest scales in which case it MAY be arranged in a pixel-like manner (Though there are many other ways it could be arranged.) but this has no evidence for it as yet. It may be best to say you are simply information, a unique energy pattern. After all, should you be hit by a truck down that street of yours you'd be gone. There'd be stuff left behind, be it colored pixels or small solid balls of matter, but the specific order that made up you would have been destroyed.

[@Biskawow]

yes Erik, the way of your thinking is correct. Its because we don't really exist and we are part of a simulation.

[@Tom-fh3zg]

.... I don't wanna be just a pixel

[@marcinna8553]

yes, but maybe no.

[@DiegoLopez-eo7xn]

Feynman is so awesome that we need a whole episode (or more) to explain his genius.

[@craigwall9536]

Be careful what you wish for....

[@sampaxs]

i need more!! listned to all podcasts of startalkradio and all your movies. love it! keep it up.

[@hindigente]

I had never been more eager for the next episode!

[@roeltz]

The last time I came this early, the Universe was still opaque.

[@thetexasranger]

Leonardo Rothe Tagliafico I came early once upon a time... my wife wasn't too happy though

[@watsisname]

I chuckled.

[@PatchyE]

Damn you are early

[@Jakubanakin]

Wait, how do different fields interact? When electron absorbs photon it absorbs part of another field? How? Can all fields interact with each other? Can there be (infinitely?) many quantum fields we havent detected yet? Is it even in theory possible to detect them all? So many questions, so few geniuses :(

[@william41017]

Jakubanakin as all fields are all everywhere in the universe they can interact with each other, some fields interact more with a specific field, some other less and others not at all. When eletron "absorbs" a photon it's just their respective fields interacting

[@Jakubanakin]

Yeah but how does that happen? What exactly happens with the fields when they interact? Also, If they can interact what makes them distinct? Why they dont just merge?

[@thedeemon]

Interaction will be covered in episode about Feynman diagrams (most probably the next one). If you take Dirac equation for electrons from last episode and add local gauge invariance principle you'll have to change derivative to covariant derivative that includes another field which turns to be the photon field. You'll get an equation where the way electron field changes with time depends on values of photon field, this is how they interact mathematically before second quantization. After second quantization instead of wave functions your equation now describes quantum field operators made of particle creation and annihilation operators. Where previously you had a term multiplying electron and photon field with some coupling coefficient, now you have this term meaning combination of electron annihilation, photon creation or annihilation and electron creation operators, whereas coupling constant (also known as charge) remains a number that will affect total probability. So when electron "absorbs" photon it's described as three operators: annihilate the original electron, annihilate the photon, create a new electron in another state, such that conservation laws hold. And probability of this event is defined by the coupling constant, the electric charge in this case. This term becomes a part of overall evolution operator that describes how everything changes with time. It can be derived from the Lagrangian. And Lagrangian is usually guessed from first principles. Two fields interact when there is a term in Lagrangian that includes both fields and some coupling constant that says how strongly the two fields interact. This constant becomes the charge. The bigger it is, the more probable the interaction, the stronger it influences end result. Interaction itself consists of annihilating source particles and creating new particles. Each interaction "event" becomes a node in Feynman diagram that's used to calculate all this stuff. To understand how it all works it's not enough to watch a few 10 minutes video. One needs years of studying and hundreds of pages of textbooks.

[@lukefieldwalker9665]

photon is generally a pack of energy, carried by the wave of light. Photon doesn't act, like an atom. We should think about light, as about wave, which is emitted by atoms in the photon field. Particles interact with eachother, by resonance of waves, which they emit in the medium...

[@Rubbergnome]

Field equations never describe wavefunctions for the system, even before 'second' conventional canonical quantization. It would be like saying that the equation for a particle's trajectory describes a single-particle wavefunction. What would be ok is to say that a free field equation happens to have solutions that describe wavefunctions in the single-particle subspace of free Fock space, because you have a mapping between the quantum field and a state created by acting with it on the Fock vacuum. But the interpretation of field equations is not in terms of wavefunctions.

[@rproyecto]

I really aprecciate too much the videos you make. I feel its so amazing that this channel exist!!!!!!

[@gabemoser6493]

Finally the video I've been waiting for Thank you love pbSpaceTime

[@jack8n]

<a href="#" class="seekto" data-time="375">6:15</a> Matt: That would be like trying to do your finances by tagging and tracking the movement of each individual dollar! Cryptocurrencies: _allow us to introduce ourselves ;)_

[@docthorium1562]

How exactly is the electromagnetic field quantized? Does its magnitude always remain an integer multiple of some small value? If so, how does quantized charge work?

[@warezpl0]

AWW, the episode ends just when Richard Feynman work was going to be discussed. The man has influenced me greatly on many matters, and I can't wait to hear about his work. Looking forward to the next one.

[@colinshawhan8590]

Yes, I agree. He was truly a fine man. Ha ha ha. Ha ha ha ha ha. Sorry...

[@Nik-vc7ox]

I liked the rpusode on intereference patterns. Really put things into perspective.

[@BaronVonQuiply]

_"Hey guys! I have a new theory - QED!"_ I don't get it... therefore what?

[@subhasishbaidya8600]

When he said all particles are oscillations in space the whole thing suddenly makes sense. Until then I was watching the whole thing like a chameleon😅😅

[@MelloCello7]

The chameleon comparison is such a visceral analogy 😅😅

[@WilliamDye-willdye]

The best aspect of PBS Space Time is that it's often over my head, but just within reach if I study a bit more.

[@richardoh419]

Why are these videos so fun?! Thank you PBS Space Time!

[@djschultz1970]

Personally I think Matt himself brings it better, easier and faster than Michio Kaku, Neil Tyson, Bill Nye, Sean Caroll, Lawrence Krauss, Brian Green and every other science educator out there! I still insist you watch/read/understand all the aforementioned names! plus the names of every pioneer of our current science, which Ive heard matt mention multiple times. Plus watch every lecture every name above has ever given us access to (life goals) to the best of your ability

[@ickorling7328]

DD SS thats because Matt its more correct than those named 'scientists'. Matt is simply a researcher of real scientists.

[@tehyonglip9203]

i’ll say Spacetime provides the most accessible and complete courses of physics with rigorous explanation compared to other educators out there

[@bothewolf3466]

And...AND...he does it without crappy political asides...or nose in the air catty remarks about religion, like SOME (not all) of those you mentioned.

[@dylansimmons799]

I love this but it makes my head have a quantum spin!

[@andyeverett1957]

Someone hit a homerun with this series. Well done and quite thought provoking.

[@andyeverett1957]

Oh, and having an actual scientist as the host a big plus.

[@morganseppy5180]

@PBS Space Time FYI: Starting at <a href="#" class="seekto" data-time="251">4:11</a>, the closed captioning has no captions. The last caption is "This is exactly how light behaves". Love your channel

[@Stahlwollvieh]

Love how "Quantum Electrodynamics" abbreviates as QED - "Quod erat demonstrandum"

[@lexscarlet]

I love the tone of this video. This is a good defense against those BEAUTIFUL EQUATIONS LED THEM ASTRAY idiots. Massive strides have been made

[@Wulfzz]

This was good. I kind of understood it, somewhat well, after having read up on the basic principles of quantum mechanics.

[@NonDelusional74611]

This video was eye-opening!! Well done!

[@tse0123]

"I drink wine and know stuff" Tyrion Lannister

[@DrumBeat231]

This show has slowly left me more and more behind. The concepts covered are getting more difficult over time and I'm getting lost (or I'm just not paying enough attention).

[@UlaisisP]

you are not alone, lets re-watch it!

[@Vank4o]

I keep rewinding and sometimes rewatching episodes. It helps a tiny bit.

[@UlaisisP]

not going to happend :D

[@NonDelusional74611]

Try it...just slightly high. Helps.

[@UlaisisP]

I´m always high.

[@IceyJones]

i would like to see a nice vid about the quantumchromodynamics from you. ur the only deeper channel i understand ;-)

[@dsp4392]

Top notch video once again. Clear and concise.

[@firebrain2991]

Did anybody else think of math when he shortened quantum electrodynamics to QED?

[@scp3999]

i got war flashbacks

[@LKAChannel]

Firebrain Quod erat demonstrandum

[@LordAmerican]

It took me back to Linear Algebra. It was an interesting class, one of my favorite math courses, but fucking hell there are so many proofs that you're required to do.

[@recklessroges]

I thought of Latin.

[@chalkchalkson5639]

^^I guess in the Venn diagram of nerds physics and maths have a pretty big overlap... Though I haven't seen a nice and oldschool "QED" or even "quod erart demonstrandum" in quite a while now, everyone is using that little \square

[@straaths]

I heard about something called 'aether' at my physics lessons. I also remember that this 'aether hypothesis' was abandoned. How aeher differs from field? For me it sounds like the very same concept. Am I missing some crucial difference?

[@NuclearCraftMod]

The aether was a proposed medium in which electromagnetic waves propagated. It was actually never much more that a qualitative idea.

[@UlaisisP]

aether is an hypothetical substance, different from air and water. air and water, have different properties in the "fields", as would aether if it existed. I should leave it to the real nerds.

[@guerreiro943]

Aether was an hypothetical material that filled the universe entirely. It has a popular concept on the 19th century to explain the propagation of light. According to many scientists of the time, light didn't propagate through a vacuum, but through the aether. However, we now that is not the case, and that light indeed travels in a vacuum. Field, as explained in this video, is a region in space where every point has a value. Think, for example, of the temperature in a room, or the force of gravity in a gravitational field. I hope I succeeded in making the distinction clear to you.

[@anteconfig5391]

I remember saying the same thing. It does sound like the same thing. I think the aether made predictions that turned out not to be true.

[@milton3204]

It has nothing to do the ether at all. QFT is a relativistic formulation of quantum mechanics, relativity specifically states that absolute references cannot exist; a direct contradiction of the ether theory.

[@doncourtreporter]

I always thought Matt was taping short segments which he read and memorized. I just learned that he writes them (wow) so I now understand how he rattles off such heavy material so fast. Wow again.

[@MeatPops]

Thanks for the birthday present guys! You rock!

[@michaelnovak9412]

I really like the direction of the videos, in the future will finally get to string theory.

[@TakenTooSeriously]

I don't like when you say "Space Time" because that means it's over.

[@feynstein1004]

Same here

[@JM-us3fr]

I get nervous every time he says it

[@thetrip9970]

hi love your work you you do a compilation of all ur videos so i can fall asleep and learn at the same time please i could make it for you

[@Ergzay]

I was so looking forward to this!!! Make more!!!

[@tcl5853]

OK got it now, a particle is actually a vibrational mode of something or other. Hummm.... so a particle isn’t actually an object of some kind, or an actual thing consisting of matter, but an excited vibrating jiggling point, or point-ish ( point-ish to give Heisenberg credit) area of the fabric of space time. That some humans call a particle to confuse all the other humans. I suppose matter really isn’t anything either, other than vibrating jiggling areas that our brains cannot see or comprehend properly. Which of course is why we have to put up with trees, rivers and beautiful bad ass snow leopards. Doesn’t it just piss you off that we can’t see reality for what it really is? Yep, it’s just fate, right? I’m doomed to putting up with seeing “fields” covered with wildflowers and the like for the rest of my life.

[@vacuumdiagrams652]

I have a question about what you said about the fine structure constant around the 10 minute mark. You say that QED predicts the "relative value" of the fine structure constant to a precision of 1 part in a billion. Of course the fine structure constant is a parameter, not a prediction, so... are you talking about the running of the coupling, or did you really mean the electron anomalous magnetic moment? PS: I've been planning to do a quantum mechanics exposition video using the very same string analogy, because it's one of those things that you don't get even in an actual QFT course. In my opinion not enough time is spent on the Fock space picture before people go on to calculations. So I guess you kinda scooped me. Thanks for the callouts, by the way :)

[@AutisticThinker]

Love all your episodes Matt, but this one is my fav!!!!

[@guillaumemaurice3503]

Thank you for sharing this video that was very interesting.

[@wackedupYUMYUMS]

I understand 5% of every episode and im ok with that

[@colinshawhan8590]

You will understand in discreet packets. A V-shaped thing will send a squilly line towards you and you'll go, "Aha! I understand QED!" But you'll have to emit a neutrino, so make sure you're not pointing it at anyone you like.

[@coco3612]

😑

[@dominikmiller3870]

Do these fields expand with the universe? If yes, why does´nt the matter, which is an oscillation in its field, should´nt a vibration always expand in its medium? And if all matter would be expanding (with the same rate everywhere, so no observers, made out of matter could reconize it) could this explain gravity?

[@nostalgiafactor733]

Dominik Miller been wondering this as well

[@johnarbuckle2619]

Dominik Miller THIS

[@ObjectsInMotion]

Short answer: no. You have a misunderstanding of what the expansion of the universe is. I'll explain it if you're still curious.

[@johnarbuckle2619]

Anthony Khodanian Please explain it

[@william41017]

Anthony Khodanian I'm just waiting for the explanation

[@fitingsthdown]

since this video, reddit has really exploded with great questions relating to this subject :)

[@kahdargo7]

MOAR QFT!!!! This is possibly my favorite episode to date. Can't wait til we get to Feynman! One question though...the Feynman equation at the beginning looked weird. I must be reading it wrong, but it looked like it had a charge and a positron moving backwards along the time axis. Wait...HAS MATT DISCOVERED TIME TRAVEL???

[@DrShaym]

Why was Dirac always slouching?

[@jamicochran8961]

Daddy

[@jamesbentonticer4706]

Perhaps he was thinking about the quantum vacuum energy prediction.

[@frankdimeglio8216]

@@jamesbentonticer4706 THE CLEAR, TOP DOWN, SIMPLE, AND BALANCED MATHEMATICAL PROOF OF THE FACT THAT E=MC2 IS F=MA: E=MC2 IS F=ma ON BALANCE. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE; AS ELECTROMAGNETISM ENERGY IS GRAVITY !!! Gravity IS ELECTROMAGNETISM/energy. TIME is NECESSARILY possible/potential AND actual IN BALANCE, AS E=MC2 IS F=ma ON BALANCE; AS ELECTROMAGNETISM/energy is gravity !!! INSTANTANEITY is thus fundamental to what is the FULL and proper UNDERSTANDING of physics/physical experience, AS E=MC2 IS F=ma IN BALANCE; AS the stars AND PLANETS are POINTS in the night sky; AS ELECTROMAGNETISM/energy is gravity. THE SUN AND what is THE EARTH/ground are E=MC2 AND F=ma IN BALANCE. TIME DILATION ultimately proves ON BALANCE that E=MC2 IS F=ma ON BALANCE, AS ELECTROMAGNETISM/energy is gravity. (The sky is blue, AND THE EARTH is ALSO BLUE. CAREFULLY consider what is THE EYE.) Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS E=MC2 IS F=ma ON BALANCE; AS ELECTROMAGNETISM/energy is gravity !!! (THEREFORE, the rotation of WHAT IS THE MOON matches it's revolution.) "Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent with/as what is BALANCED electromagnetic/gravitational force/ENERGY, AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 IS F=ma. GRAVITATIONAL force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE, AS E=MC2 IS F=ma ON BALANCE; AS ELECTROMAGNETISM/energy is gravity !!! Energy has/involves GRAVITY, AND ENERGY has/involves inertia/INERTIAL RESISTANCE. ("Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/energy is gravity. E=MC2 IS F=ma. Carefully consider what is THE EYE.) Objects (AND what is the FALLING MAN) fall at the SAME RATE (neglecting air resistance, of course), AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. Again, carefully consider that the stars AND PLANETS are POINTS in the night sky !!! (Very importantly, outer "space" involves full inertia; AND it is fully invisible AND black.) It ALL CLEARLY makes perfect sense. BALANCE AND completeness go hand in hand. SO, carefully consider what are the ORANGE SUN AND the fully illuminated and setting MOON ! Both are the size of THE EYE. Think LAVA !!! The Moon is ALSO BLUE on balance. Therefore, E=MC2 IS F=ma IN BALANCE !! It all CLEARLY makes perfect sense !!! Carefully consider THE MAN who IS standing on what is THE EARTH/ground !!! Great !!! E=MC2 IS F=ma ON BALANCE !!!! By Frank DiMeglio

[@kenwaying]

when daddy matt uploads

[@chalkchalkson5639]

Our prof described the properties of the different descriptions in term of their non quantum analogies, L2/Hamilton-Jakobi is great for a handful of particles, when the number of them is constant, but if you got several orders of magnitude more, you need Liouville, which is actually pretty similar to a field description. Most of these can be pretty easily derived from d'Alembert which is a very simple and intuitive axiom, which then gives you an intuitive understanding of what the QM equations mean. (Not an intuitive understand of QM though :/ )

[@schwenke069]

Concept sounds solid ... but hard to imagine. Analogy of air as a field really helped. And then I heard ... two quantum negative quarks with negative spin always travel along the path perpendicular to the rayon field ... or something like that. Working on it. Baby steps. Thanks.

[@brazzelon]

I really don't want to be that guy, but Faraday was the first person to consider light as an exitation of the electromagnetic field. he was inadequate in math so he never proved it, until maxwell came along straight dropping knowledge. #represent #faradayswag

[@jacanchaplais8083]

Brazzelon that was the inception of classical electrodynamics and field theories in general, but there was no indication of particles existing as excitations on the fields, and nobody had even considered wave particle duality until de Broglie/Planck/Einstein, so no contradictions here.

[@mycount64]

so what is a magnetic field made of ? boy this just created more questions than answers...

[@watsisname]

Tiny compass needles spinning furiously.

[@mycount64]

It can be observed interacting with matter... it must be something. It is not a quantum probability wave... which is just an equation. We can see iron filings line up along the field, we see a compass needle line up with the field... indeed it is something.

[@randomguy7790]

In solid matter it's created by assembly of atoms, which are aligned by the direction of their spin. In star systems by the assembly of celestial bodies, aligned by the orientation of their magnetric fields. In galaxies it's created by assembly of star systems, which are alligned by the directions of their magnetic fields... It creates the structure of a fractal... And what carries the magnetic field? Science tells, that virtual photons - I say, that virtual field lines...

[@mycount64]

I have read this explanation before regarding virtual photons. It is not widely or often discussed. Can you direct me to either lecture, video or reading (for the layperson) magnetic field, quantum fields theory or QED. When discussed I can grasp most of the concepts unfortunately I am lacking the math. I could pick up that book by Feynman on QED. anyway cheers

[@frankschneider6156]

+AW Crowe Maybe that's not the answer you were looking for, but it's the truest you'll get: QFTs are made of maths.

[@bhdamiati]

Thank You ^^ I was waiting long for this video... Even that I can't understand all of it... It cleared some questions I had. I still don't really understand what exactly is a magnetic field and how it's mechanic works into being able to move objects tho :p

[@MacAttackProductions]

Have they ever done a video on magnetism yet? It often seems tied to quantum physics and it would be interesting to see a quantum take on it

[@Krystaltho]

I can't wait for Leonard Susskind's newest book!

[@andriypredmyrskyy7791]

I was waiting the entire episode for a Quantum ElectroDynamics Quote Est Demonstratum pun. QED, spacetime has no sense of humour :P

[@gthakur17]

hands down one of the best episode because how the narrative is driven in story format. Many book and articles fails to capture the chronology of events how scientist hit a roadblock and then others came to help.quantum mechanics was not a one man theory it literally required the efforts of 100s of scientist all over world to develop it to what we see today. The problem faced by one was resolved by the theory of other and so on.

[@stevebell321]

Watching this made me recall the conundrum I have with the dubious Double Slit Experiment that somehow shows that an electron can be in multiple places at the same time. When I apply the vibration within a field concept to the electron, suddenly the double slit experiment makes total sense! According to Quantum Field Theory and Quantum Electrodynamics, an electron is nothing more than a vibration within a field. This is the same for a photon, a proton and all the quantum particles. So instead of thinking about firing an individual electron at the two slits, we are actually sending a vibration through the electron field, in the direction of the two slits. A vibration with a direction is a wave. Therefore we are not firing a single electron at the two slits and finding that it can be in two places at the same time, but rather we are sending a wave in the "electron field" towards the two slits and just like a wave in water passing through two slits, the electron wave is split into two more waves on the other side which then create their own interference pattern. The ramifications of this are that by measuring the interference pattern we could determine the exact amplitude of the electron vibration within its field. We could also then do the same for every quantum particle to determine the amplitude of each particle within its own field. This should then theoretically allow us to make determinations about the states of very fields of those particles. For example, does each particle field have a different "viscosity" which in turn determines what the particle is, or is it simply the nature of the vibration; amplitude, frequency, time domain, that determine what we define as the particle.