You don't need to go all the way to physics for free will - you need look no farther than psychology to determine whether free will exists or not. Actually, you

You don't need to go all the way to physics for free will - you need look no farther than psychology to determine whether free will exists or not. Actually, you don't need to look any farther than a serious philosophical treatment of what you mean by "free will" to see that the question itself is a confused one based on untenable (or even more confused) assumptions. Nevertheless the belief in free will is very important for human happiness; or at least, happy and/or successful people tend to believe in free will, or just that their will is free and they're the master of their fates and the captain of their souls. That is often the motive behind free will arguments, which generally have a very powerful smell of rationalization about them, but a thing is not necessarily true because human happiness (or even life) requires believing it is true or leads to the feeling it must be true.