In physics, Schrödinger's cat is a thought experiment in which a cat is trapped in a box with a particle that has a 50-50 chance of decaying. If the particle decays, the cat dies; otherwise, the cat lives. Confusing much? Maybe Astrophysicist Paul Sutter explaining it will help! It's a 50-50 chance.
Category
🤖
TechTranscript
00:00 As far as we can tell in the subatomic world, everything is just so ridiculously and frustratingly random.
00:08 You look at an electron and sometimes you look at it and it'll have a spin pointing up.
00:13 And the next time you look at it, it'll have a spin pointing down.
00:16 And you're like, "Can't you just pick one? Why do you have to be both? Why do you have to keep flipping back and forth?"
00:23 I'm Paul Sutter and this is Paul Explains the show where I, you know, explain.
00:30 The whole machinery of quantum mechanics is designed to translate the probabilities of what you might measure when you go to make an observation.
00:44 In the case of an electron spin, the language that we use in quantum mechanics goes something like this.
00:52 The spin of the electron is in a superposition of both spin up and spin down states.
01:00 And then when you go to measure it, something happens and it chooses one of those states and that's what you actually measure.
01:08 But some of the founders of quantum mechanics didn't really like how this was being described.
01:15 One of those people was Erwin Schrodinger, one of the founders of quantum mechanics.
01:20 He looked at this example, this language, and developed a thought experiment to show just how lame this language is.
01:29 He said, "What if you put a cat in a box, you close the lid, and you put some radioactive element in there?"
01:35 And just say that there's a 50/50 chance that the radioactive element will decay and it will poison the cat and it will kill the cat.
01:45 But there's a 50% chance that it won't decay, nothing bad will happen, and the cat will live.
01:50 Now, as long as you have that box closed, you don't know what's going to go on.
01:56 You don't know if the cat is alive or dead.
01:59 And then you open up the box, you perform your measurement, and you see either a dead cat or an alive cat.
02:06 Classically, non-quantum mechanically, we would think that at some point the cat might or might not die.
02:14 But our observation of it, our measurement of it, has absolutely nothing to do with what's going on inside the box.
02:21 Either the cat is dead or it is alive, we just haven't found out yet.
02:27 But Schrodinger pointed out that in quantum mechanics, the way we're supposed to think about it is that the cat is both dead and alive.
02:40 It exists in the quantum superposition of deadness and aliveness.
02:46 And when we open up the box, that is the moment of the choice. That is the moment of the cat becoming dead or becoming alive.
02:57 But until we open up the box, it is both dead and alive.
03:02 And Schrodinger said, "This sounds really dumb. Do you actually expect us to believe this when it comes to quantum mechanics?"
03:11 And everyone else who was working on quantum mechanics said, "Yes."
03:17 How do you wrap your mind around this? Well, maybe you don't have to.
03:23 Maybe reality is just weird, and we should leave the cats alone.
03:28 Meow.
03:31 [Meow]
03:33 (electronic music)