# I Can the spin states of a spin1 particle be modeled?

1. Mar 13, 2017

### edguy99

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.

2. Mar 13, 2017

### Staff: Mentor

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?

3. Mar 13, 2017

### Staff: Mentor

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: Mar 13, 2017
4. Mar 13, 2017

### edguy99

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 grammer

Last edited: Mar 13, 2017
5. Mar 13, 2017

### Staff: Mentor

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