What are the uses of quaternions in Physics?

[C.E]

Hi, I really want to learn about the applications of quaternions in Physics (I have posted in this section as apparently they can be used a lot in Mechanics). Anyway I was wondering if anyone knew of any good books (Undergraduate level),websites or interesting facts about this topic.

 

[granpa]

I don't know much about them but I heard that they are used to express rotations. you might want to look at this:
http://modelingnts.la.asu.edu/

the above link is about 'geometric algebra' which is, like quaternions, an extension of the concept of imaginary numbers which involves the idea of rotations. but it seems to be broader and possibly more useful than quaternions (as you can see from the links on that page)

 

[ExactlySolved]

I have never seen quaternions in mathematical classical mechanics books (Arnold, Abraham) but I would be interested if anyone knows of a quaternionic discussion along these lines.

It goes a little beyond the undergraduate level, but quarternions are the natural way to express instanton solutions in classical yang-mills SU(2) gauge theories (which are like a more advanced version of Maxwell's equations) cf Atiyah 1979.

I just want to comment that 'geometric algebra' is not a mainstream topic, and that personally I regret the time I've wasted on these kinds of things during my education. Until the math dept offers a class on geometric algebra, I don't recommend bothering with it.

 

[Cantab Morgan]

You might try looking at the computer graphics literature. Quaternions are used in video games.