Don Lincoln: prediction

Transcript context

…So antimatter was predicted in nineteen twenty-eight. Paul Dirac was trying to merge quantum mechanics and relativity because the original Schrödinger equation did not, was not relativistic. And in doing so, he basically, the equations were complex, but in the end it came down to something like equation squared equals one. You take the square root of both sides, you get equation equals plus one or minus one. Plus one was the electron, minus one was something. He didn’t know what it was. There was some conversation for a while, thought maybe it might be the proton, but that didn’t seem to work out. And so he insisted that his equations were right and that there was an antimatter, he didn’t call it an antimatter, but a positively charged sibling of the electron, what we now call the positron, the antimatter electron. So it was predicted. It was discovered in nineteen thirty-two by Carl Anderson and his student Seth Neddermeyer. They saw an antimatter electron. And that was pretty cool. So that right there, they knew it was real. Antimatter was predicted, it was observed, that’s that. In nineteen fifty-six, the antimatter proton was created, and that required a large particle accelerator, high enough energy to make it, and that was done at Berkeley. And a year later, the antimatter neutron was discovered. So at this point, and now jumping ahead to now, we can make, using energy by smashing particles together, we can make antimatter protons, we can make antimatter electrons. We have gone so far to make antimatter helium nuclei. So we have made two antiprotons and two antineutrons, combined them together to make an antimatter helium nuclei. This has been done, been observed, no question. At CERN, they have gone so far as to make antimatter hydrogen. They take a beam off one of their lower energy accelerators. They make antimatter protons. They collect them, they slow them down, they cool them to almost absolute zero. They take sodium-22, which makes antimatter electrons. They slow them down, they bring them together, they coalesce them, and they make literal antimatter hydrogen atoms with an antimatter proton surrounded by an antimatter electron. And they have done incredible measurements. They have agitated the atoms and caused it to emit light. They have looked at the light that comes out of antimatter atoms. And the question is, is does the light coming out of antimatter hydrogen atoms have exactly the same spectral characteristics as ordinary hydrogen, which we predict that it does? And the answer is it does. So the tests have been staggering. We now know a great deal about antimatter hydrogen. the same spectral characteristics as ordinary hydrogen, which we predict that it does? And the answer is it does. So the tests have been staggering. We now know a great deal about antimatter hydrogen. Recently, recently like twenty twenty-three, I believe it was, one of the experiments called ALPHA at CERN made antimatter hydrogen, put it in a bottle and released it and watched which way it would go. Did it fall up or did it fall down? Because while it kind of makes sense maybe to think that maybe antimatter falls up in the same way that we have Coulomb’s law, you’ve got electric charges, and they might attract or repel. However, there was lots of ample theoretical reasons to believe that antimatter also would fall down. So they did this fantastic measurement, and they first they put in hydrogen, and they calculated that if they did this, something like eighty percent of the hydrogen atoms would fall through the bottom of the bottle, and twenty percent would go through the top just because gravity is very weak and the atoms will escape wherever they do, but there will be a bias pulling hydrogen atoms down. So they did exactly the same thing, and what did they find? They find that antimatter falls down. Now, they do not have a good enough measurement at this time to say that the gravity that antimatter experiences is one hundred percent that of matter. What they have measured is that antimatter fell down with a seventy-five percent the strength of regular matter, but there were big uncertainties. There was plus or minus point one three due to the experiment, which was good but imperfect, and plus or minus point one six due to their theoretical model. So it’s like point seven five plus or minus something like point two nine. And that means there’s a good chance it’s between point five and one- … which means it’s consistent with one. So they are improving their measurements. Well, if I can, I would love to take a bit of a tangent on that topic ’cause I went down a rabbit hole watching some of your videos on antimatter. And I mean, Fermilab was the hub for the production of antimatter for quite a while.…

Stored transcript either side of the excerpt. The highlighted words are the published quote; the surrounding text is unedited source, never generated.