ehsjr wrote:
I thought the idea was that you can know where the
electron is or what direction it is travelling, but
never both at the same time. So (theoretically) you
could know exactly where it is located, which would
lead to it popping in and out of the space under
examination, since the "exactness" restricts the
space to ever smaller observational limits.

It makes it hard as hell to paint the damn things. :-)

Ed

Well, yes, that's a somewhat better description of the
uncertainty principle. But it really is talking about
a particle's position and momentum. The direction
of travel is included in that.

Still, electrons do not pop out of existance, as one
might believe after reading the wikipedia description.
The space the electron might be located in (after having
been located precisely at some earlier time) is not
infinite in size, since the electron can not travel
faster than the speed of light. Choose a large enough
volume of space, and you can be certain the electron is
still located somewhere within it.

Mark