Richard Feynman Lecture on Quantum Electrodynamics: QED. 8/8

Second lecture:http://www.youtube.com/watch?v=UUAG3yDInQQ&feature=channel_video_title

Richard Feynman gives us a lecture on Quantum electrodynamcis, the theory of photons and electron interactions which incorporates his unique view of the fundamental processes that create it. one of the 3 winners of the 1965 Nobel prize in Physics for his work, Feynman is was an expert on quantum mechanics and developed the Path Integral formulation of Relativistic Quantum mechanics, used in Quantum Field Theory, interpreted the Born series of scattering amplitudes as vertices and Green's function propagators in his famous diagrams, the Feynman Diagrams, and also worked on the fundamental excitations in Liquid Helium leading to a correct model describing superfluidity using phonons, maxons and rotons to describe the various excitation curves.
other fields of work include the Feynman-Hellmann Theorem, which can relate the derivative of the total energy of any system to the expectation value of the derivative of the Hamiltonian under a single parameter, e.g volume.
he also worked on the Rogers Commission report during the investigation of the 1986 Space Shuttle Challenger disaster, where Feynman famously demonstrated how the Booster Rocket O-rings, which are elastic sealing joints, became less resilient and subject to seal failures at ice-cold temperatures by immersing a sample of the material in a glass of ice water- his high intelligence and independant way of looking at the world often made him "a real pain" in the eyes of other, less skilled, Commission members.
Feynman's own investigation reveals a disconnect between NASA's engineers and executives that was far more striking than he expected. His interviews of NASA's high-ranking managers revealed startling misunderstandings of elementary concepts, such as safety proceedures.
Although Feynman got plenty of media coverage due to him being on the Commission, he was often told to stay quiet about NASA's more sinister secrets and tactics in space exploration.

Category:

Science & Technology

Tags:

• Richard
• Feynman
• Quantum
• electrodynamics
• Field
• Theory
• Mechanics
• photons
• electrons
• electromagnetism
• nuclear
• forces
• fundamental
• physics
• lectures
• QED
• elementary
• particles
• chemistry

[MuonRay]

I have uploaded the long awaited second part(see link on the description).

the 3rd part will be up soon and I hope to upload the 4th part which will be about other physics(Quantum Chromodynamics, the Electroweak Interaction and the Standard Model of Particle Physics)

[kjrunia]

Thank you so much for this awesome material. From the giant himself. I'm so glad the probability of me finding these videos was sufficiently high to actually find these videos. Can I be of any help with the other videos? I'd be more than happy to cut them into YouTube acceptable pieces.

[MuonRay]

@kjrunia I have the videos I just need the time to cut them-> I get holidays in 2 weeks so I will be posting them then. we physicists like to work during summer.

[StAngersucks]

@MuonRay If you increase the limit of your account, you could upload longer videos and skip the splitting part.

[MuonRay]

@StAngersucks They let me do that now.

[SZambayon]

Thank you so much for uploading this lecture!

I wanted to ask you if you have the videos of "the next lecture" which he reffers to repetedly?

[MuonRay]

@SZambayon I will try and post it as soon as possible. These lectures are long, and have to be shortened down into smaller segments; youtube will not let me use the full versions of the lectures without having sponsership- in other words they only allow large videos if they have lots of pointless adds at the start from big, faceless, out-of-touch and greedy corporations.

[Austin25254]

As an electrical engineering student I learned that you can represent waves in time as complex numbers which behave somewhat like vectors. Was the entire adding vector/complex number thing just a mathematical representation of constructive and destructive interference of a wave.

[wakatuvia]

He had an answer for everything observable in nature. If he were alive today, mankind would have been at a different level.

[StAngersucks]

@MuonRay Well, fine, man!

[747823]

@Nomoreidsleft

We only call them crazy when they're wrong, and they always are.

[Nomoreidsleft]

@Vape4life It's not playing with dice, when you already know all the outcomes. It's just us humans, who don't and think it's probability. We also think that time is linear and call those that can see the future, present, and past at the same time crazy or seers.

[Vape4life]

@Nomoreidsleft But you can't be certain of where the electron is at any moment in time....so any answer will have to have probability built in. Heisenburg uncertainty principal doesn't allow you to know the exact location and speed of an electron.

[Vape4life]

so where we stand is nothing can be determined exactly...there will always be probability involved that can't (at least at this point) be accounted for. So God DOES play dice...

[Nomoreidsleft]

Has there been any refinement done to QED? Seems to me that he can't explain why the reflections are calculated on the probability wheel. Don't we know by now that this is base on the degrees of freedom o fthe electron cloud around the atom that's doing the reflecting? The photon hits the electron cloud, causing and electron to be ejected. Since the electron being ejected is orbiting around the atom, the direction of reflection depends in where it was in the shell.