Re: I forget & I can't find what's a 1/2 spin, 0, 1, etc....


guskz@xxxxxxxxxxx wrote:
Nishu wrote:
It would be a litttle difficult to imagine the particles with spin
1/2,-1/2 as it is a concept of sub atomic particles.
Now suppose you have an arrow pointing in one direction ( <---- ). You
start rotating it until it comes in it's orignal form. You'll realize
that you have rotated 360 degrees. This arrow has spin =1. Now you have

a double headed arrow, symmtrical. You rotate it until it comes in it's

orignal form. But now you have to rotate it only 180 degrees as the
arrow has two heads( <---> )

Hard to imagine since your arrows are linear where as a spin is angular
and I believe perpendicular to the particle's travel direction....

Spin = 1, I can picture a particle which has spun angularly at 360
degrees

Spin = 2, I can't picture a 2 headed arrow *spinning* at 180 degrees
apart, how can you spin in two opposite directions? = impossible....a
spin is in one direction???



It has nothing to do with "spinning" at all. It's a rotational
transformation. You're just rotating the double headed arrow either
clockwise or counter clockwise. Since both ends of the arrow are
indistinguishable, it only requires a rotation of 180 degs to bring it
back to its original configuration. Unlike the single headed arrow,
whose ends are distinguishable, and so it will take a full 360 degs to
bring it back.

.