Reflections on Subrahmanyan Chandrasekhar

52:29other aspect but one of them had a different par decay and the other one had a different par decay. Okay? One of them was going into two, the other one was going into three. So one of them had an even par and the other one had an odd par. If you think that par is par is the same. Right? On the left hand side we've got the um the theta which is sorry on the left hand side we've actually got the tow that's going into three pons and on the right we've got the the pi that's going into two right that this is just a schematic diagram showing like that decay. >> Yes. >> This is very weird. >> Yeah. >> Because if the law of conservation of par is true which everyone assumed it's true then the decays must end in the

53:09same par. But here we've got the same particle that looks pretty much the same >> but they have aspect >> diverging >> but they have this diverging decay >> decay parody. >> Okay. >> Okay. >> And so now it's like how how how could these two be so similar and yet have such a different thing. >> Right. >> One one um possible resolution is that these are two very different particles. >> Okay. The other possible ability is that these two are the same particle but par is not conserved in this process. >> Okay. >> In all the stuff that we've talked about with electromagnetism with gravity par

53:51is conserved. But in this particular thing that we are observing >> not >> it is not. >> Okay. >> Okay. >> So the conservation of par is not universal. >> Yes. Maybe not all the laws of physics obey the conservation of par. Maybe there's an exception. Okay, >> maybe gravity is not the exception. Maybe electromagnetism is not the exception exception. But maybe there's something else. Okay, and this is where the hero of our story story um Yang Chen Ning comes in. Okay. >> Okay. So, Yang Chen Ning um born in 1922 in Hefe province in China. Um his dad was actually a professor at Singua

54:31University in Beijing. He was a math professor. He's one of the few people who actually did his PhD outside of China and then came back, okay, >> to teach in China. So he's had exposure to group theory from a very early age. Group theory is the mathematics of symmetry. >> Okay. So he's he's gearing up for this fight early on, right? Um he's forged in war actually like during the Japanese invasion of um Kunming in 1937. This was before the allout break of war in the Pacific theater where the United States got involved after um Pearl Harbor. The Japanese were doing all sorts of random stupid nonsense, terrible stuff in

55:11China. And so all of the Chinese academia actually went down to Leanda in the southwestern province and they sort of conglomerated all of their academic might >> in the south away from all of the fighting. And this is where Yang Cheng Ning >> um did his undergraduate and his PhD. >> Okay. No, sorry, not his not his PhD, his undergraduate and his masters. Okay. And he actually learned about quantum mechanics at a very early even back then. I mean it's it's quite remarkable because quantum mechanics was still quite early but he was the the university was so good that he was already getting exposure to quantum mechanics at that early undergrad mast's

55:54level um he gets on one of these liberty boats from China to the US he caught it in Kolkata actually these are boats that were set up um after the war to bring in people from the Indonesian Indo-Chinese theater that was happening in Burma >> to the United States so he goes through Kolkata through the Red Sea, through the Mediterranean to New York. There were no direct boats to San Francisco. So, he actually had to come the other way all the way around the Earth, right? Um he ends up in New York. Um he's he stays I was just watching some of his interviews from Stony Brook University, which is where he ended up and spent a majority of his academic career. Um they have these incredible interviews of of the

56:35man Yang Chang Ning. And um he was talking about how like you know when he