Richard Feynman
c/richard-feynman
Richard Phillips Feynman was an American theoretical physicist.
c/richard-feynman
Richard Phillips Feynman was an American theoretical physicist.
…be in. However, you cannot put more than one electron in the same state on account of the fact that the particles are Fermi particles. But one remark. The states that we've been talking about so far, we didn't consider the spin. Each state is therefore…
…had if they were alone. In addition, they, oh, but then you must remember that they may behave like either Bose or Fermi particles, depending on the problem. If these were electrons, excitations, for instance, in a crystal, they would have to behave like…
…Fermi particles, depending on the problem. If these were electrons, excitations, for instance, in a crystal, they would have to behave like Fermi particles, because to say that this electron is here and that one is there, or vice versa, we need to have an…
…two k's are equal, I can't arrange such a thing. So the two particles can't occupy exactly the same state with their Fermi particles. I want to make some applications of this or describe some applications of these ideas to organic chemistry. The molecule…
…point of the lecture, see, I made a mistake in planning it. I shouldn't have worried about this. What I should have done is the Fermi gas, which is what I wanted to do. And I thought I could do the chemistry and the Fermi gas and this. But I should…
…I should have done is the Fermi gas, which is what I wanted to do. And I thought I could do the chemistry and the Fermi gas and this. But I should always do the most important things first. But the logic of the independent model, I thought, was worth…
…this amplitude would have to be equal and opposite, but they represent the same event if photons are identical. If it were Fermi particles, it would be the other way around, photons, but they're not, they're the same, and you can't have the opposite…
…mesons, and by that I do not mean muons. That's not a meson in the way we use the words. And the Fermi particles correspond to nucleons, baryons, and neutrinos and muons. An interesting problem is when there are two particles that are bound together…
…the amplitude where there's no such exchange must come with a minus sign because we have really only exchanged one pair of Fermi particles. On the other hand, however, if the probability amplitude for such processes is negligible, if the energy is so low…
…is that composite objects, under circumstances in which the composite object can be considered as a single object, behave like Fermi particles or Bose particles, depending upon whether they contain an odd number or an even number of Fermi particles inside.…
…object, behave like Fermi particles or Bose particles, depending upon whether they contain an odd number or an even number of Fermi particles inside. There turns out to be another coincidence. All of the particles which I mentioned that are Fermi particles…
…an even number of Fermi particles inside. There turns out to be another coincidence. All of the particles which I mentioned that are Fermi particles also happen to have a spin value, J, which is half integral, like the electron is a half, the proton is…
…what the rule is for different kinds of particles. There are two kinds of particles, and they have names. A particle is called a Fermi type or a Fermi particle if the sign here is negative that you have to use in exchange. And the one particle that's…
…different kinds of particles. There are two kinds of particles, and they have names. A particle is called a Fermi type or a Fermi particle if the sign here is negative that you have to use in exchange. And the one particle that's a Fermi particle is…
…or a Fermi particle if the sign here is negative that you have to use in exchange. And the one particle that's a Fermi particle is an electron. Another is a proton. Another is a neutron. Another is a neutrino. The Bose particles. Ours is. The gamma…
…it? Okay. That's right, it's both electrons. This was both particles the same, but both Bose particles, and these are two Fermi particles. Now in general, with Fermi particles, if they're in such a circumstance that you can't distinguish between them, you…
…electrons. This was both particles the same, but both Bose particles, and these are two Fermi particles. Now in general, with Fermi particles, if they're in such a circumstance that you can't distinguish between them, you must subtract them instead of adding…
…the divergence of dn is equal to s minus dn dt, with the great equation for the diffusion of neutrons. I say it that way because Fermi taught it to me. Now, this dn dt is 0 for the steady case that we're talking about. And we have an example of the…
…in a certain number of 10 to the minus 15 centimeters, or units of Fermi's. 10 to the minus 15 centimeters is one Fermi. Well, I think that covers fairly well the kinds of concepts we have of distance, how we can measure distance from the smallest…
…for a while that maybe the conservation law worked only statistically on the average for large scale But it turns out that Fermi, I mean Pauli, suggested no, that the fact that the energy doesn't check out is because there's something else coming out,…
…at least a half integer, as we'll learn the rules of compounding angular momentum later. So it turns out, therefore, that every Fermi particle or a composite that imitates a Fermi particle has an half integral, in this sense, an integer divided by 2 value…
…the rules of compounding angular momentum later. So it turns out, therefore, that every Fermi particle or a composite that imitates a Fermi particle has an half integral, in this sense, an integer divided by 2 value for its spin, while every Bose particle…
…way, an integer, either 0, 1, and so on, for its spin, so that there's Also possible to say that all the Fermi particles are half integral and the Bose particles are integral. Now, there comes a question. Why is the sine negative for electrons?…
…other isotopes, so it's evidently a quantum mechanical effect. The other isotope containing, as it does, two protons and a neutron obeys Fermi statistics and not Bose statistics. And the rules for Fermi statistics are not the same. It is not so in the…
…The other isotope containing, as it does, two protons and a neutron obeys Fermi statistics and not Bose statistics. And the rules for Fermi statistics are not the same. It is not so in the case of Fermi statistics that particles try to go into the same…
…statistics and not Bose statistics. And the rules for Fermi statistics are not the same. It is not so in the case of Fermi statistics that particles try to go into the same state. What do Fermi particles do? So now we turn to the same consideration…
…the same. It is not so in the case of Fermi statistics that particles try to go into the same state. What do Fermi particles do? So now we turn to the same consideration that was made previously for Bose particles, but now for Fermi particles. Suppose…
…do Fermi particles do? So now we turn to the same consideration that was made previously for Bose particles, but now for Fermi particles. Suppose that we tried to put two Fermi particles into almost exactly the same direction. The amplitude to go one way…
…the same consideration that was made previously for Bose particles, but now for Fermi particles. Suppose that we tried to put two Fermi particles into almost exactly the same direction. The amplitude to go one way would be this way, 1B2, and the amplitude…
…way would be this way, 1B2, and the amplitude to go the other way is A2B1, as previously described. If, however, we have Fermi particles, then the amplitude to put them into the same condition reversed must be subtracted from the first. Let me say that…
…approach each other. So the product of A1, B2, and A2, B1 approach each other, and the net result is nil. Therefore, the Fermi statistics are even easier than in the Bose statistics case. It just isn't possible for two electrons, for example, to get into…
…degree of intelligence on the part of the audience. There are a number of most remarkable effects as a consequence of the Fermi that the Fermi particles cannot go into the same state. Almost all of the excitement of life, almost all of the peculiarities…
…on the part of the audience. There are a number of most remarkable effects as a consequence of the Fermi that the Fermi particles cannot go into the same state. Almost all of the excitement of life, almost all of the peculiarities of the world,…