Feynman Diagrams - Sixty Symbols

With Ed Copeland and Roger Bowley

[JamesSmith-ekor]

The man at 0:25 is an excellent communicator. His voice is so calming and clear, and his face is so kind and empathetic.
He gives off an auroa of safety and intellect which I love. Extremely attractive and a great quality to have.

[angrystickfig]

I strongly suggest that anyone interested in Feynman Diagrams reads Feynman's book "QED: the strange theory of light and matter". Heck, I suggest that you read it even if your not interested in Feynman Diagrams, it's a fantastic book.

[squalea]

Isn't it amazing that humans can study and understand concepts this complex? These videos completely blow me away.

[IBITZEE]

I love the honesty of the first person in the video saying that he could not fully understand it... Only great men have the perspective of their standing!!!

[ShubhamBhushanCC]

A lot of physics feels like something you could work out if you really tried. Then there is Feynman diagrams. I don't think I'd be able to come up with something like this if I thought about it for a million years

[dezerterone]

I'm not a physicist, after high-school was afraid of it and because of this lectures I'm addicted to it. Thanks a lot to all who contribute!

[stijnservaes]

Amazing we used these last year of high school. How something complicated can be explained in simple andbeautiful diagrams is amazing!

[smbhax]

Awesome tabletop diagrams! I love Feynman diagrams; they make me feel like I can almost understand what's going on. The videos of Feynman's Auckland lectures in which he explains and demonstrates them are not to be missed!

[naimulhaq]

The first time I was introduced to Feynman Diagrams 40 years ago, I was blown away. One particular diagram caught me by surprise.It describe a particle and an anti-particle producing a photon which emitted an electron. Now that I vaguely understand virtual particles and vacuum quantum fields and the Higgs fields, I can understand why I was surprised, how original his diagrams were. I have no doubt that his diagrams will be key to understand the mysteries of not only dark matter and dark energy, but an unified theory.

[Boredom]

Can i just say, yes you are! You've helped so many people love physics, given even more a great understanding of it, and given people hours of entertainment. If i could, i'd name an element after you.

[krazyking]

I am always blown away by the quality of these videos.

[mixolydian]

Wonderful one of my favourites. Feynman has always been my physics hero and have read a lot of books about him and by him, also some amazing lectures he did in New Zealand. For anyone struggling with these concepts i would recommend the New Zealand lectures and the book Genius by James Gleick, the lectures by Feynman because they are derived from his thoughts and Genius because it puts these ideas and the roots of quantum mechanics in context, showing the evolution of his ideas and others. It can be very difficult to understand without a context in my opinion.

[burstingdynamics]

Feynman was a magician.... He was the greatest of them all. Salute to him

[MrSammywow]

i am doing this is AS physics at the moment and this helped me so much, thank you.

[MuonRay]

Feynman Diagrams come from the Interaction Lagrangian for Quantum Field Theory. The Dirac Lagrangian density is first made Imaginary using the Hermitian Conjugate Operator. From there we get the standard Hamiltonian Density and using the S-matrix we can do a the Wick Expansion to get the propogation terms that satisfies the initial particle state the best. the Feynman Diagram is then in correspondence with the term selected, and then use the Feynman Rules to compute the Probability Amplitude.

[frankhaugen]

Feynman's way of simplifying complex things. was incredible!

I listened to "The Feynman Lectures on Physics" as a 15-year old, and I had no problem understanding everything

[Badroucl]

If anyone needs some more technical details about the diagram, without drowning in them, i suggest Prof. Susskind's lecture on string theory and also the lecture about higgs boson. But for a smooth survey this video is just great. thanks for sharing.

[stevenvh]

A nice thing about FDs is that you can read them any other way. If you reverse the time scale a positron is an electron going back in time, for instance.

[Kurtlane]

@puncheex, I might be wrong, but I think that in addition to diagrams discussed here, where particles move forward in time, there are diagrams where some partcles move back in time, coming from the future and moving into the past.

I belive this has something to do with the difficulties of accepting the diagrams.

Right now, the accepted opinion is that particles don't move backwards in time, but behave "as if" they do.

[chap]

I learned how to do Feynman Diagrams in high school... feels melancholy though, as the physics is ridiculously interesting, yet the ideas are devilishly complex. Damned IB HL Physics.