Physicists Chen Ning Yang and Tsung-Dao Lee proposed in 1956 that the weak nuclear force need not respect parity symmetry, meaning nature could distinguish left from right even though electromagnetism and chemistry do not. Chien-Shiung Wu at Columbia University confirmed this with a beta decay experiment on cobalt-60, showing the universe does care about mirror symmetry. The same year, biochemist Arthur Kornberg used E. coli at Washington University in St. Louis to isolate DNA polymerase, the enzyme that actually carries out DNA replication rather than the strands simply reassembling on their own.
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Wu's cobalt-60 experiment is described as the landmark test of parity violation, but Wu did not share the Nobel Prize that Yang and Lee received for the theoretical prediction.
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Kornberg's discovery of DNA polymerase won him the 1959 Nobel Prize in Physiology, three years after the initial breakthrough.
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The hosts note that Earth's biological molecules like carbohydrates are one-handed (left-handed), and frame parity violation as related to the deeper question of why chemistry could in principle have gone the other way.
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1:34:36>> 1956 discovery of parody violation. >> Yes. This was the focus of our episode of Chening Young. So parody violation is this idea that everything should be the same in the mirror. Electromagnetism doesn't care about mirror world. >> Yes, chemistry really doesn't care about the mirror world. I know that all of our polymers and all of our carbohydrates in biology are right-handed or I should say left-handed, but there could be an alien world that started off right-handed. So the question is does physics care about if my X is in this direction and Y is in this direction is the Z always in this
1:35:18direction or can the Z also al also be down that's a choice that we're making parity violation is this idea that Chening Yang and Sunda Lee came up with where they said perhaps not >> and there's one way to test it. um Chen Chung Wu at Columbia University, she made a landmark experiment of beta decay on cobalt 60 that showed the universe does care about left and right. It was huge. Crucially, um Wu did not win the Nobel Prize and Chening did and all of the physicists at the time were like, "What are you guys doing?"
1:35:58And again, if you are curious tangentially, the uh Yang Mills episode that we did touches on the concepts of this left-handedness, right-handedness. It's one of my favorite episodes that we've done. Uh definitely worth uh a peak. 1956 discovery of DNA polymerase. >> Yes. The question is, we've got DNA now. How does DNA replicate itself? Watson and Crick come up with the okay, I just unzip and then the A's and the T's go. You know, thermodynamically that doesn't make any sense. I mean, it's not like the A's are going to just diffuse and like randomly get together with the T's. There's got to be some kind of enzyme that does it. DNA polymerase is that
1:36:38enzyme. Biochemist biochemist Arthur Kornberg. He used E.coli at the Washington University in St. Louis, which by the way, so many Washington University St. Louis in uh physiology. Um, a great place for medicine and biology research. His landmark breakthrough won him the 1959 Nobel Prize in Physiology. >> Three years was in his lifetime. Right