Can the spin states of a spin1 particle be modeled?

  • Context: Undergrad 
  • Thread starter Thread starter edguy99
  • Start date Start date
  • Tags Tags
    Particle Spin States
Click For Summary

Discussion Overview

The discussion revolves around the modeling of spin states of a spin-1 particle using the analogy of spinning CD players. Participants explore the implications of this analogy in relation to classical and quantum mechanics, particularly focusing on angular momentum and stability.

Discussion Character

  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant describes an experiment involving spinning CD players and questions whether their behavior can be analogous to the spin states of a spin-1 particle, particularly the spin0 state.
  • Another participant argues that the original question may not pertain to quantum physics, suggesting it is more aligned with classical physics.
  • Some participants express uncertainty about the appropriateness of the analogy, debating whether the spinning CD players accurately represent quantum mechanical addition of angular momentum.
  • A later reply suggests that the analogy does not hold, asserting that the behavior of the CD players cannot be used to model quantum spin states.
  • One participant proposes further exploration of the spin0 state analogy by considering the effects of separating the CD players and observing their motion.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether the spinning CD players serve as a valid analogy for quantum mechanical concepts. There are competing views regarding the relevance of the analogy to the behavior of spin-1 particles.

Contextual Notes

Participants express various assumptions about the relationship between classical and quantum mechanics, and the discussion remains open to interpretation regarding the validity of the analogy.

edguy99
Gold Member
Messages
449
Reaction score
28
There is a video from the Space Station here:

At around the 1 minute mark, you see the stability of the CD player when the CD inside is spinning. Don Pettit goes on to tape additional CD players together at 90 degrees to the original to make it stable in 2 directions, but my questions is are a little different.

1. He occasional gives a small tap to the spinning CD player causing it to wobble a bit. If he hit it a little harder, would it flip?

2. If he taped 2 CD players together, one on top of the other rather then at 90 degrees, he has 3 ways of doing it. He can have both CD's spinning to the right, both CD's spinning to the left, or 1 CD spinning right and 1 CD spinning left. In the case of 1 CD spinning right and 1 CD spinning left, would this act as the spin0 state of a spin1 particle and required no energy to "flip"? Ie. the 2 CD's taped together would not act like a gyroscope but more like a CD that is not even turning?

This question would be very easy to answer with access to the space station, but unfortunately I have no access and not enough money to buy a trip up there although I would love to go with some CD players and a bit of duct tape to try it myself.
 
Physics news on Phys.org
This question doesn't seem to have anything to do with Quantum Physics or spin-1 particles. It looks like a straightforward classical physics question. Should this thread be moved to the Classical Physics forum?
 
PeterDonis said:
Should this thread be moved to the Classical Physics forum?
It depends on whether the question here is about the behavior of spinning CD players or whether the spinning CD players are a good analogy for quantum mechanical addition of angular momentum. If the former, it should be moved; if the latter, the answer is "no".

I expect that @edguy99 will be able to clarify.
 
Last edited:
Nugatory said:
It depends on whether the question here is about the behavior of spinning CD players or whether the spinning CD players are a good analogy for quantum mechanical addition of angular momentum. If the former, it should be moved; if the latter, the answer is "no".

I expect that @edguy will be able to clarify.
Definitely the later. "whether the spinning CD players are a good analogy for quantum mechanical addition of angular momentum" is the question. I tried to narrow the scope by specifically talking about 3 states of a spin1 particle. I feel it does model it correctly, but I am not sure there will be general agreement on this, hence the question and hopefully some debate.

Depending on the reaction to this concept (ie. if allowed), I would like to expand the spin0 state analogy and cut the tape on the spin0 state and watch what happens as the CD's drift apart. I would expect them to continue spinning in opposite directions, one up and one down state, but I would also not be surprised to see some "precession" or "wobble" in the 2 CD players again preserving all conserved quantities where both CD's would precess in opposite ways, but if visualized back together, the precession would cancel out (conservation of spin and angular momentum).

*edited spelling and grammar
 
Last edited:
edguy99 said:
"whether the spinning CD players are a good analogy for quantum mechanical addition of angular momentum" is the question.

Then the answer Nugatory gave is correct: no, it isn't.

Thread closed.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 16 ·
Replies
16
Views
2K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 21 ·
Replies
21
Views
3K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 42 ·
2
Replies
42
Views
5K
  • · Replies 24 ·
Replies
24
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K