Helical diffraction theory

47:24>> Helix meaning a spiral. Okay, >> a spiral molecule I subjected to X-rays. What is it going to look like? He comes up with the Cochran Cric van theory with his two um colleagues in 1952 and he publishes this paper and what it shows is that the the scattering amplitude like the where the the the dark spots and the light spots should be they should come up in X. >> Mhm. [clears throat] >> They should have these spots. >> Mhm. >> And they should have um the cross shape is a signature of a helix. The angle of the cross tells you what the pitch of the angle is of that helix, right? And things like that. >> So, they came up with a formula for if you're looking at a a a helix object.

48:05>> Yeah. And I and I have the photograph from the X-ray. >> What would that tell me about the structure of the helical object? >> Got it. Got it. It's kind of like a a dictionary or like a translation between a results list and what is the like interpretable meaning of like the raw results. >> Exactly. Okay. So Watson at this time moves there after a PhD in uh in Chicago posttock in Copenhagen and he strikes up an immediate friendship with Francis Crick. They think very alike in terms of these >> scientific problems. They're very much alike. Okay. So they start working on the DNA structure with whatever information that they have. >> We're going to need a photo like that on Princeton's campus in black and white in

48:46the in the whole in the whole. We're going to need one of those. >> Yeah, we're definitely going to need one. [laughter] Yeah. Um, so this is sort of setting up >> Yes. >> that situation, right? Cavendish >> versus >> Cavendish, you've got these theorists and these X-ray crystalographers that are trying to figure out >> what an X-ray cris picture would look like. And then in King's College London, they're the guys that are actually taking the photos, >> right? >> Okay. So, you have the people taking the pictures >> and you have the people creating the >> framework for the interpretation of the pictures. >> Yes. And they're both kind of cooking. >> They're both kind of cooking, right? At the same time. >> Yes. And they're cooking at the same time. And they're kind of competing against each other

49:26>> cuz they want to be each one of them. >> Each one wants to be first >> for the whole thing. >> They realize They realize what this is, >> right? Yeah. Yeah. >> Everyone knows what this is. >> The treasure map was already created. >> Yes. >> They know that there's a city of gold.