Originally posted by benzun_1999
dear reader,
I came across shrodinger's model of an atom. it said that electrons don't move. it is completely weird and it is tough for me to get any idea of it.
-benzun
all for god
Yes it is tough, but it is important to wrap your mind around if you care about how the world is made.
Stating that the electrons don't move is not quite right. What quantum mechanics says is that they dont't have a well-defined position or velocity. Their position and speed are not zero but something that is not definite and constantly changes.
Sometimes this is visualized as a cloud, representing the probability that the electron is at some point near the nucleus. And you could form a similar cloud showing the probability that the electron has any given speed.
If the electrons were truly little particles whirling around the nucleus like planets around the sun, then atoms wouldn't work. For circling is acceleration (basic physics) and accelerating charged particles will radiate EM waves (basic electromagnetism - see the "accelerated charges" thread up in Classical Physics). So the electrons would radiate EM. And this would give two problems:
1) We don't see this EM radiation coming out of atoms, and
2) The electron, by emitting that EM would lose energy, and couldn't keep up its orbit, it would spiral into the nucleus and be lost.
Even before modern quantum mechanics was invented in the 1920s, physicsists knew about these problems and the dealt with them by "magic". Bohr said, well the electrons in their orbits just DON'T radiate, unlike every other kind of charged particle. Other physicists were uneasy about this, but whaddaya going to do?
Then Heisenberg, and Schroedinger, and Dirac came along and all was light. Probabilities solved the problem.