MadSci Network: Physics |
There are two ways to answer your question. What you've brought up is a
question of classical mechanics vs. quantum mechanics. Quantum mechanics
was invented to explain questions like yours in a more sensible way around
the turn of the century. Niels Bohr's model of the atom essentially put to
rest the pre-20th century "planetary" model of the atom. But enough
history.
For example, we know the moment of inertia is 1/2 m r^2, so we plug in the mass and orbit of the electron, and find ridiculously small numbers.
This gives us a really small effect. Now you might ask, but the electron
is spinning so fast, wouldn't it have a large enough torque to measure?
Well, yes and no. The kinematical torque (the torque from the electron
orbiting the nucleus) is so small, even accounting for the high speed
revolution, that we probably couldn't measure it directly (say with some
sort of torque-meter). But then, we can't just stick an atom inside a vise
or something and twist it and measure it's restoring force anyway- it's
simply too small.
In the mathematical formulation of quantum mechanics, we take care of the fact that the electron doesn't move in strict planar orbits, we take care of the fact that the electron is so small we can't know its position precisely, etc. This is why quantum mechanics can seem so strange and hard to grasp.
It is, in fact, due to simple questions like yours and the subsequent study of such problems, that we now can account for the lines in atomic spectra, and can explain the world of the atom in a sophisticated manner.
Try the links in the MadSci Library for more information on Physics.