Ether before relativity in quantum theory also

Click For Summary
SUMMARY

The discussion centers on the implications of Galilean transformations in non-relativistic quantum mechanics, specifically regarding the Schrödinger equation. It is established that the wave function, represented as \(\psi(t,x)=\exp(i(Et-px))\), is not invariant under Galilean transformations, leading to different representations in various inertial frames. In contrast, the Klein-Gordon and Dirac equations maintain Lorentz invariance, allowing their solutions to remain valid across different frames without redefinition. This highlights the necessity of an ether coordinate set in non-relativistic theory to account for these discrepancies.

PREREQUISITES
  • Understanding of Galilean coordinate transformations
  • Familiarity with the Schrödinger equation and its implications
  • Knowledge of Lorentz invariance in relativistic quantum mechanics
  • Basic concepts of wave functions in quantum theory
NEXT STEPS
  • Research the implications of Galilean invariance in quantum mechanics
  • Study the Klein-Gordon equation and its Lorentz invariance properties
  • Explore the concept of ether in the context of non-relativistic physics
  • Investigate the differences between non-relativistic and relativistic quantum mechanics
USEFUL FOR

Physicists, students of quantum mechanics, and researchers exploring the foundations of quantum theory and the relationship between classical and relativistic frameworks.

jostpuur
Messages
2,112
Reaction score
19
I think this all makes sense to me, but I've never heard of this in lectures or in books, so I'll check if I'm getting this right.

In one dimension Galilean coordinate transformations are [tex]x'=x-ut[/tex] and [tex]t'=t[/tex]. Momentum transforms as [tex]p'=p-mu[/tex], and energy is [tex]E=p^2/(2m)[/tex]. With a quick calculation I get [tex]E't'-p'x'=Et-px-\frac{1}{2}mu^2t-mux[/tex]. So this means, that a wave plane solution [tex]\psi(t,x)=\exp(i(Et-px))[/tex] of the Shrodinger equation is not a solution in other inertial frames? In relativistic theory it goes better, as [tex]p_\mu x^\mu[/tex] is Lorentz invariant, and a solution of Klein-Gordon equation is always a solution also in other inertial frames.

So if I assume, that a wave function is real in the sense, that there truly is some complex number associated with each space time point, in non-relativistic theory I must assume an ether coordinate set? I think it somehow remarkable, that a Shrodinger equation is not Galilean invariant like the Klein-Gordon or Dirac equations are Lorentz invariant. :rolleyes:
 
Last edited:
Physics news on Phys.org
Yes, you are correct. In non-relativistic quantum mechanics, the wave function is not invariant under Galilean coordinate transformations. This means that in different frames of reference, the same wave function will appear differently. For example, a wave packet traveling in one direction will appear to travel in the opposite direction when observed from a different frame of reference. Additionally, the energy of the system is not preserved under Galilean coordinate transformations, and so solutions of the Schrödinger equation must be redefined in order to remain valid in other frames of reference. In contrast, solutions of the Klein-Gordon and Dirac equations are Lorentz invariant and remain valid in different frames of reference without requiring redefinition.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 22 ·
Replies
22
Views
3K
  • · Replies 32 ·
2
Replies
32
Views
2K
  • · Replies 24 ·
Replies
24
Views
3K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 3 ·
Replies
3
Views
5K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K