Looking Glass Universe | Is Spin Angular Momentum afterall? ('What is Spin?' follow up) @LookingGlassUniverse | Uploaded September 2015 | Updated October 2024, 1 week ago.
On why I was very wrong. In my previous video, I said that spin isn't very linked to angular momentum at all- but in fact, there's a key property of angular momentum that spin has, suggesting they are linked after all.
Previous video (What is Spin?): youtu.be/cd2Ua9dKEl8
Book recommendation: Modern Quantum Mechanics by Sakurai. This is a classic textbook that I hadn’t read until recently, but I’m now such a fan. However, I think that you will benefit most from this book if you already know the basics of QM and what a deeper look. That said, the only prerequisite is linear algebra.
Homework:
I’m interested, did you guys find this video’s argument convincing? Should we call spin intrinsic angular momentum? Is it weird to even try and explain spin with classical ideas and using classical analogies? Is intrinsic angular momentum inherently meaningless phrase anyway? Every time I ask these sorts of questions I get a really diverse set of opinions all well argued so this should be fun.
Second, I mentioned that you can only get an electron back to its original state by rotating it twice. Last time, some people commented that this isn’t so weird- some classical things do this. What do you think of this? Do you know an example?
Finally for the classical mechanics fans, I explained why a rotating thing in a stern-gerlach machine doesn’t just flip and point up. But now explain why the force that it experiences is proportional to how much it was pointing up to start.
On why I was very wrong. In my previous video, I said that spin isn't very linked to angular momentum at all- but in fact, there's a key property of angular momentum that spin has, suggesting they are linked after all.
Previous video (What is Spin?): youtu.be/cd2Ua9dKEl8
Book recommendation: Modern Quantum Mechanics by Sakurai. This is a classic textbook that I hadn’t read until recently, but I’m now such a fan. However, I think that you will benefit most from this book if you already know the basics of QM and what a deeper look. That said, the only prerequisite is linear algebra.
Homework:
I’m interested, did you guys find this video’s argument convincing? Should we call spin intrinsic angular momentum? Is it weird to even try and explain spin with classical ideas and using classical analogies? Is intrinsic angular momentum inherently meaningless phrase anyway? Every time I ask these sorts of questions I get a really diverse set of opinions all well argued so this should be fun.
Second, I mentioned that you can only get an electron back to its original state by rotating it twice. Last time, some people commented that this isn’t so weird- some classical things do this. What do you think of this? Do you know an example?
Finally for the classical mechanics fans, I explained why a rotating thing in a stern-gerlach machine doesn’t just flip and point up. But now explain why the force that it experiences is proportional to how much it was pointing up to start.
