John Wheeler - Work with Richard Feynman (49/130)
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- čas přidán 8. 10. 2017
- To listen to more of John Wheeler’s stories, go to the playlist: • John Wheeler (Scientist)
American physicist, John Wheeler (1911-2008), made seminal contributions to the theories of quantum gravity and nuclear fission, but is best known for coining the term 'black holes'. A keen teacher and mentor, he was also a key figure in the Manhattan Project. [Listener: Ken Ford]
TRANSCRIPT: I had, at that time, a student who was working on exciting things with me, and that took all my imagination. Richard Feynman had been graduated from Massachusetts Institute of Technology, and he arrived in the fall of 1938, as a graduate student. By some freak of fate or good luck, in his task, he was assigned for me as somebody to grade papers of the students in my courses. So every week, at a certain time, he'd come in with the papers graded, so I could give them back to the students, and we'd go over what the students' difficulties and premises were. And then we got off on other things. And I can recall talking to him about the idea, how unnatural it is that a particle that is jiggled here should lose energy only to a particle some distance away later, why not also earlier? Little by little, as we got into these questions, we found ourselves getting more excited. I recall sitting one day in the living room at home, on a Sunday afternoon, figuring on the back of an envelope; look, if a particle here radiates energy outward, and jiggles all the particles far away, what will be the effect of these Far Away Particles back on this particle? According to views then current, it couldn't have any effect then because the effect had to go out, that'd take time, a million years, say, and then another million years to come back. So this particle would never see the consequences until two million years later. But I said to Feynman- suppose, if the effect comes back before it starts, so-called Advanced Potentials, and I found that the effect was of the right order of magnitude to explain the observed loss of energy of this particle, the force acting on it, it slowed it down and took energy away from it, coming from the effect produced by these far away particles. That seemed a big contradiction to the normal order of time, but Feynman was happy to go along with this. But I came out with an answer off by a factor of two. Can you figure out what I did wrong? Well, he figured it out. And then we thought these ideas were sufficiently interesting, why not go round and see what Einstein could contribute on it. So he and I went round to 112 Mercer Street, and Einstein was kind enough to talk about this, things with us, and he told us how years ago he had written a paper with a German physicist, Walther Ritz. To me it's the height of the ideal of science, two people considering a problem as carefully as they can, they come out with opposite views, but they write down what they agree on, what they disagree on, and what should be done to settle the disagreement, and here were Ritz and Einstein. Ritz said the world was built so that forces only act later than the action. And Einstein said the asymmetry in time that we observe in nature is not due to the forces, it's due to statistics, the fact there are large numbers of particles out there, somehow or other. So he was sympathetic to the point of view that Feynman and I had developed. And that gave us great encouragement to go ahead and publish this. - Věda a technologie
Truly blows my mind how the titans of physics all managed to come together and converse, almost casually figuring out the order of the universe and everything in it
Feynman and Wheeler, just walk on over to mention this idea to Einstein, Brilliant...
Feynman : What do you think we should do about this idea?
Wheeler : Well, we could run it by Einstein.
Feynman : Sounds good. Is he home? Shall we call him first?
Wheeler : Nah. Let's just walk up there and see if he's free to discuss this.
(mind blown) Can you imagine just casually go up to Einstein's house to discuss physics?
To me, it's like Hitchcock and Spielberg went to see Kubrick to ask him what he thought about one scene.
The LEVEL of GENIUS POWER in that house, that day, is hard to comprehend.
Intelligence level over 9000
I can't understand why Wheeler hasn't got Nobel Prize.
What a gentleman Wheeler is.
Wheeler was brilliant physicist!
Madematician yes, I am. More in quantum computer physics (interface between ultracold atoms and light)
Hi sister
I am 15 year old teen here for the love of Physics
Feynman and Wheeler, just walked around corner to meet Einstein.
Great physicists, "Physicist of the Physicists" having mentored more than 45 PHD students at Princeton University.
Many contributions to the development of physics in the last century.
Albert Einstein made contributions to physics. His brother Frank made a monster.
Kind of like asking why, when you open your door does the wind blow in but not before
That's because of the Pauli exclusion principle, of course
What is he talking about with the radiation and 1 million years?
This was the origins of the idea of an "electron travelling backwards in time" i.e positrons which later became a crucial component of Feynman's formulation of Quantum Electrodynamics that he presented at Pocono.
This was the origins of the idea of an "electron travelling backwards in time" i.e positrons which later became a crucial component of Feynman's formulation of Quantum Electrodynamics that he presented at Pocono.
Let's say a charge here interacts with a charge a million light years away (like part of a star, say). That means it takes this charge's radiation a million years (traveling at the speed of light) to reach that far away charge and excite it, causing it to re-radiate energy. This re-radiated energy then takes another million years to travel back to the first charge. So the first charge waited 2 million years (round trip) to feel the radiative interaction with the far away charge. That is the conventional story.
The modification he's referring to is the Wheeler-Feynman action at a distance theory of classical electrodynamics, which uses both advanced (backward in time) and retarded (delayed in time, "normal") potentials. You can google it.
I came here after TENET to revise
They came up with possibly the most far out physics ever.
Long live freedom and democratic equality
Came here after TENET
Even a 2x speed he speaks too slowly.
Pre-quantum entanglement era....
Nope its QED
Heisenberg-SchrodingerEmc2 , right - “spooky action “ , I agree that Einstein theorized it long before anyone else. This is not what Wheeler is talking about, that’s what you’re saying?