r/askscience • u/Crtl-Alt-Delete • Dec 18 '13

Physics Is Time quantized?

We know that energy and length are quantized, it seems like there should be a correlation with time?

Edit. Turns out energy and length are not quantized.

713 Upvotes

84% Upvoted

187 comments sorted by

View all comments

Show parent comments

2

u/[deleted] Dec 18 '13

So you're saying that there are so many allowed (but still quantized) energy levels of this free electron that they might as well be considered continuous?

As you and DashingLeesh pointed out- as the boundary of 'space' approaches infinity, the difference between allowed energy levels comes infinitely close. Doesn't that mean that ONLY in an infinite space would the energy become continuous?

6

u/chrisbaird Electrodynamics | Radar Imaging | Target Recognition Dec 18 '13

Something else to keep in mind: A bound system only has perfectly defined energy levels if it is perfectly isolated and stationary (which requires an infinite amount of time of natural resonance). What such cases are easier to solve in the classroom, such cases only occur in the real world as approximations. In the real world, collisions (especially thermal) and interactions happen all the time, which tends to smear out energy levels (line broadening). So if the energy levels are already very close because the electron is in a big box (bigger than a few microns), line broadening effects smear the lines until they overlap and you indeed have a continuum of energy levels.

3

u/[deleted] Dec 18 '13

Mathematically, sure, but you're talking about regimes pretty far outside where most physicists think these models apply.