AMA | October 2024

7287.697 - 7311.655 Sean Carroll

That is exactly the same origin as the thermodynamic time asymmetry. I think we'll talk about that a little bit later in the AMA. So therefore, in fact, if someone says I have a quantum spin, I'm going to measure it. Oh, look, it's spin up. Tell me what its state was before I measured it. You can't. all you know is that there was a greater than zero contribution from spin-up, okay?