Take the 2-minute tour ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.

I remember once, as a child, thinking that objects do not really "move," but that at a very small scale they would have to "disappear" and then "appear" again at their newly shifted position, just the way computers render moving particles based on refresh rates. This relates to Zeno's paradox which is solved by infinite sums.

Then I heard about quantum wave function collapse and the double slit experiment, and then thought: oh, maybe nature solved the problem by turning anything that wants to move into a wave instead of making a single particle "appear" and "disappear" in new positions as it moves. Waves is by the way a very elegant solution in comparison.

My question is: was my thinking correct? are waves (and wave collapse) nature's way to make particles move around?

share|improve this question
I don't think so, there are conservation laws which don't let you destroy matter. –  jinawee Dec 29 '13 at 9:31
why the downvote for question? –  user117325 Dec 29 '13 at 18:01
@jinawee in quantum mechanics there is Heisenberg uncertainty principle which allows the total energy of a system to diverge for a short time. –  Anixx Dec 29 '13 at 20:18

2 Answers 2

up vote -1 down vote accepted

Motion of the particles indeed can be described as in your first point: for example, propagation of electron can be seen as a creation of a virtual electron-positron pair ahead of the propagating electron, and later annihilation of the first electron with the positron so the newly-created electron remains.

share|improve this answer
Isn't this rather philosophical? Virtual particles cannot be detected and there are theories which don't use them (for example, QFT in the lattice). By that reasoning you should say that when a particle goes from A to B there are infinite particles created-destroyed all over the Universe. And the OP's vision of wavefunction collapse and movement seems incorrect, but I don't know enough QM to be sure. –  jinawee Dec 29 '13 at 20:25
@jinawee everything concerning the interpretation of quantum mechanics is quite philosophical. But this model explains for example, why in certain circumstances particles can seemingly move faster than light en.wikipedia.org/wiki/Hartman_effect –  Anixx Dec 29 '13 at 20:28
@jinawee of course one can interpret it in another way: that is the particle's velocity varies as the particle propagates, sometimes reaching faster-than-light values, remaining constant only on average. But this interpretation is equivalent to that with virtual particles because an antiparticle can be actually viewed as a particle moving backwards in time. That is anti-particle moving from B to A is particle moving from A to B at super-infinite velocity. –  Anixx Dec 29 '13 at 20:35

Particles move continuously. There is no "disappear" and "reappear". If such discrete movements were the case than we should be able to detect it by scattering experiments and find that certain regions of space always seemed to be empty (similar to how they detected that atoms were mostly empty space). No experiment has detected this phenomena.

Also, the wording you chose is misleading. "Nature" doesn't solve any problem. People make the problems, and people solve them.

share|improve this answer
Why the downvote? –  mcFreid Dec 29 '13 at 17:35
see my answer. Particles continuously appear and annihilate in vacuum. –  Anixx Dec 29 '13 at 17:38
there is no "continuous move" in quantum mechanics. –  Anixx Dec 29 '13 at 17:55
I don't think that has much to do with the OP's question. There is no "spatial" aspect to the loop effects in a propagating particle. Taking your example, we could never measure the positron in the virtual electron-positron pair, else it wouldn't be virtual. So it's not like the electron dissapears at x=0 and then reappears at x=1. –  mcFreid Dec 29 '13 at 17:59
Also, the confusion with loop effects comes from the fact that the electron is never purely an electron since it's charge disturbs the vacuum state of the EM field and this disturbance propagates. Either way, the result remains that the electron and its disturbance do move continuously. With regards to QM, free particles move continuously. I don't know what you're saying by "there is no continuous move". –  mcFreid Dec 29 '13 at 18:01

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.