Are point particles always points?

  • Thread starter jaydnul
  • Start date
  • #1
516
11

Main Question or Discussion Point

Tell me if I am correct:

The wave part of wave-particle duality is a probability wave. An electron, for example, is always a 0 dimensional point (as far as we know), and the wave characteristic of the electron determines the possible locations of the electron and probability of finding it in that location.
 

Answers and Replies

  • #2
9,379
2,431
Well first off the wave particle duality isnt really how its looked from the modern perspectice:
https://www.physicsforums.com/showthread.php?t=511178

The real answer is that for all quantum objects we know of position is an observable and nothing has revealed any type of spread out structure etc for objects like an electron or photon - neutrons, protons etc - yes - but they are not considered fundamental.

Basically QM is a theory about the results of observations, measurements etc etc and since we can devise experiments that return a position we say they are point like particles - but quantum particles - not how they are visualized classically.

Thanks
Bill
 
Last edited:
  • #3
44
1
Tell me if I am correct:

The wave part of wave-particle duality is a probability wave. An electron, for example, is always a 0 dimensional point (as far as we know), and the wave characteristic of the electron determines the possible locations of the electron and probability of finding it in that location.
Yes, that's correct. But given the inherent and unavoidable uncertainty in its position, the statement "the electron is always a 0 dimensional point" is a bit misleading. What "point particle" really means is that the electron and its wavefunction have no substructure - the more energy you use to probe it the better you will localize it (although never with perfect accuracy), and you will never discover any new level of complexity. You'll just keep squeezing the wavefunction down into a smaller and smaller region.

That's by contrast with for instance a proton, where if you probe with enough energy you discover quarks. And of course electrons may well have substructure too at some small length we haven't reached yet (for example at the Planck length something different has to happen).
 
  • #4
Demystifier
Science Advisor
Insights Author
Gold Member
10,821
3,521
Tell me if I am correct:

The wave part of wave-particle duality is a probability wave. An electron, for example, is always a 0 dimensional point (as far as we know), and the wave characteristic of the electron determines the possible locations of the electron and probability of finding it in that location.
This is absolutely correct in the Bohmian interpretation of quantum mechanics, but not necessarily in other interpretations.
 

Related Threads on Are point particles always points?

Replies
11
Views
615
Replies
17
Views
948
Replies
6
Views
2K
Replies
8
Views
2K
Replies
23
Views
6K
Replies
0
Views
933
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
4
Views
2K
Top