Reproducibility — laws of physics don’t change

8:26the name of Emmy Not who was a mathematician from Goting. She was actually like she people didn't want to publish her because she was a woman. So she would publish under her supervisor's name. But there there's a there's a theorem called not theorem >> which basically codifies this idea >> that there's something I can do to physical laws that will preserve the action of the physics underlying it. >> Okay. There's we've actually like it's it's quite intuitive at at the start. Okay. >> There's a translation in space that's a

9:06symmetry. For example, the laws of physics are the same here >> as they are anywhere else in the universe. So if I Yeah. And we've talked about this before. If I set up an experiment here in one lab and I do somethingy and I measure somethingy and then I go all the way across the United States to the east coast and I set up the experiment, I'm going to measure that same thingy. Right. >> This is a LIGO is a perfect example of this. >> Yes, exactly. There's one on Livingston, there's in Louisiana and there's one in Hanford in Washington. They're both operating the same way. This LIGO wouldn't be possible if translation in space wasn't a thing. >> Right. Yes. >> Right. And but there's an inherent

9:47assumption there that >> because we're on two separate parts of Earth, >> the Earth is not really part of the experiment, >> right? We're doing enough to cancel out the stuff of Earth and like that local environment to really focus on the physics that we want. And because of the translation symmetry of physics, that experiment in Louisiana is the same as the experiment in Washington, right? That's a translation in space. Okay? There's also a translation in time. Which means if I do an experiment now and then I don't change anything and then I do an experiment you know tomorrow or a month later as long as it

10:28doesn't somehow depend on the Earth's