Are QM and SR completely compatible?

  • Thread starter Gonzolo
  • Start date
  • Tags
    Qm Sr
It's not an approximation. However, there are still open questions and problems in this area, particularly when it comes to incorporating gravity into the framework. QFT deals with the unification of quantum mechanics and special relativity, including the incorporation of spin, and has been successful in many ways. But there are still challenges and obstacles, especially in reconciling it with general relativity. So while there are some outstanding issues, overall, the combination of SR and QM has been quite successful. In summary, while there are cases where quantum mechanics and special relativity may not fit perfectly, QFT has been successful in unifying them and incorporating spin. However, there are still challenges in reconciling it with general relativity.
  • #1
Gonzolo
Hi, correct me if I'm wrong, but quantum mechanics and special relativity seem to fit pretty well together. With Klein-Gordon's equation and Dirac's equation anyway, they seem to be able to live with each other quite happily. Are there cases in which they can't? Is this what Q Field theory deals with? What are the main problems or obstacles in this area, if any? I'm talking about Special R. only here, NOT General Relativity.
 
Physics news on Phys.org
  • #2
Obviously adding special relativity doesn't make it easier, but AFAIK there aren't any fundamental problems in QFT with marrying SR and quantum physics.

Of course there are features of the Schroedinger equation (one f the most obvious being that time and space have different orders in it) that make it non-relativtsic, but as you've pointed out there are several relatvistic wave equations anyhap.
 
  • #3
The SR incremental mass not convertable to photo energy

Gonzolo said:
Hi, correct me if I'm wrong, but quantum mechanics and special relativity seem to fit pretty well together. With Klein-Gordon's equation and Dirac's equation anyway, they seem to be able to live with each other quite happily. Are there cases in which they can't? Is this what Q Field theory deals with? What are the main problems or obstacles in this area, if any? I'm talking about Special R. only here, NOT General Relativity.

Regardless of whether in Classic Mechanical or Quantum mechanical situation,
only the rest mass of the high speed particle is available for Einstein's E=mc^2 conversion; consider the following axiom:

Axiom: An intrinsic property of matter is that its mass, to the extent that the part that is the result of Einstein/Lorentz velocity-dependent mass-enhancement, can only be converted back to energy in the manner of classical physics. I.e., E = mc^2 applies uniquely to the rest mass of the high velocity material particle – before the rest mass of a particle that is mass-enhanced (by the rule of Special Relativity) becomes available for photo conversion it, along with its excess mass, behaves according the traditional conservation laws of kinetic energy and momentum.

Corollary: logically (contrapositive-wise) any loss of a moving particle’s mass (on the occasion of its impact with matter) that is manifest by an increase in heat, momentum or kinetic energy of that matter is necessarily achieved at the expense of the particle’s total mass that existed as the result of Special Relativity.

For example, when a cosmic-ray proton is cracked in two by impact each pion's mass is decreased from 469 MeV to 139.6 MeV as the kinetic etc energy of the meson increases by 330 MeV; after about 0.03 microseconds it unwinds to become a muon of mass, 105.7 MeV that finishes unwinding and moving while losing another 33 or so MeV (in about 2 microseconds) of its mass leaving only the electrons and positrons that can only be destroyed by annihilatin. possible remnants are +muon > e+e-e+ and -muon > e-e+e-.

Ipse Dixit, Neoclassic cheers, Jim
 
  • #4
uumm..perhapas i don,t agree with Dirac,s equation it implies the existence of a metric gab whereas in quantum mechanics there is no metric or gab so i think Dirac,s equation is only an approximation to quantizying special relativity...
 
  • #5
eljose79 said:
uumm..perhapas i don,t agree with Dirac,s equation it implies the existence of a metric gab whereas in quantum mechanics there is no metric or gab so i think Dirac,s equation is only an approximation to quantizying special relativity...

Dirac's equation is perfectly fine and well suited. We know that for a while now. I am absolutly positive eljose79 : SR and QM have been unified, that is the original motivation for QFT, which has been around for a while now.
 
  • #6
eljose79 said:
uumm..perhapas i don,t agree with Dirac,s equation it implies the existence of a metric gab

No, it assumes the existence of the metric gab. The Dirac equation starts with the assumption that SR is correct.

whereas in quantum mechanics there is no metric or gab

There is in relativistic quantum mechanics. Or do you think that Schrodinger's QM is the "real" QM and that Dirac's is not?

so i think Dirac,s equation is only an approximation to quantizying special relativity...

It's the exact quantization of dynamical variables for spin-1/2 particles that is consistent with SR.
 

Related to Are QM and SR completely compatible?

1. What is QM and SR?

QM stands for quantum mechanics, which is a branch of physics that deals with the behavior of particles at the subatomic level. SR stands for special relativity, which is a theory that describes how objects move at high speeds.

2. Are QM and SR compatible?

This is a highly debated topic among physicists, but the general consensus is that QM and SR are compatible to a certain extent. Both theories have been extensively tested and have been shown to accurately describe different physical phenomena.

3. How are QM and SR related?

QM and SR are two of the most fundamental theories in modern physics. While they both address different aspects of the physical world, they are related in the sense that they both provide a mathematical framework for understanding the behavior of particles and objects.

4. Can QM and SR be unified into one theory?

Many scientists and researchers have attempted to unify QM and SR into a single theory, but so far no successful theory has been proposed. The challenge lies in reconciling the different principles and equations of the two theories.

5. Why is it important to understand the compatibility of QM and SR?

Understanding the compatibility of QM and SR is crucial for developing a comprehensive understanding of the physical world. Both theories have been incredibly successful in their respective domains, but a unified theory that combines the two could potentially unlock new insights into the mysteries of our universe.

Similar threads

I Relativistic quantum mechanics
    • Quantum Physics
Replies
32
Views
2K
I Why is the SE better than the KG equation for a hydrogen atom?
    • Quantum Physics
Replies
18
Views
2K
What are the basic mathematical objects in QFT?
    • Quantum Physics
Replies
7
Views
1K
QM & Relativity: The Hardest Problems to Solve
    • Quantum Physics
Replies
5
Views
1K
B Dirac Equation: Combining Quantum Mechanics and Special Relativity
    • Quantum Physics
Replies
11
Views
1K
B Questions on QFT & QM: Is QM or QFT Absolute Time?
    • Quantum Physics
2
Replies
69
Views
5K
B QFT & QM Questions (about time, locality, gravity, etc.)
    • Quantum Physics
Replies
6
Views
1K
How much SR is needed for Purcell and Morin?
    • STEM Academic Advising
Replies
4
Views
983
A Is the quantum mechanics explanation for the propagation of light adequate enough to be understood?
    • Quantum Physics
Replies
6
Views
637
Relationships between QM and QFT Particles
    • Quantum Physics
2
Replies
38
Views
4K

Hot Threads

Recent Insights

Back
Top