Definitoon of trajectory in quantum physics, especially in path integrals

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Discussion Overview

The discussion revolves around the appropriate use of the term "trajectory" in the context of quantum physics, particularly in relation to path integral formulations and the implications of wavefunctions on determinism. Participants are exploring the conceptual nuances of these terms and their implications for understanding quantum mechanics.

Discussion Character

  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions whether "trajectory" is the correct term to use when discussing the future state of a particle based solely on its wavefunction, suggesting alternatives like "path" or "movement."
  • Another participant expresses concern over a statement from Feynman's book that implies determinism in quantum mechanics, seeking clarification on the general belief among quantum physicists regarding determinism.
  • A participant proposes that "evolution" may be a more suitable term than "trajectory" and inquires whether a large wavefunction could imply determinism.
  • One participant argues that while wave functions and path integrals can provide determinism of probability amplitudes, this does not necessarily mean that all aspects of the universe are deterministic, noting the potential for Bohmian trajectories to suggest a deterministic framework.

Areas of Agreement / Disagreement

Participants do not appear to reach consensus on the use of "trajectory" versus other terms, nor on the implications of wavefunctions for determinism in quantum mechanics. Multiple competing views remain regarding the interpretation of these concepts.

Contextual Notes

There are unresolved questions about the definitions of "trajectory," "path," and "evolution" in quantum mechanics, as well as the implications of determinism versus indeterminism in the context of wavefunctions and path integrals.

roberto85
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What is the correct way to use the term trajectory in physics when discussin path integral forumaltion calculations. Here is the sentence i am trying to complete and am unsure if i may use the term trajectory:

So the wavefunction offers a much more simplistic and perhaps more beautiful way to describe a system when compared to the kernel since all effects of the past history of a particle can be defined in terms of a the wavefunction. If we were to ignore everything we knew of it's history (or did not know this information) except for it's wavefunction at a particular time; we could calculate the future of the particle's TRAJECTORY??

Or should i just alter the sentence to say we would know its future path or movement or soemthing to that effect?

Help would be greatly appreciated, many thanks
 
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Also I am very concenred about this statement which i obtained from richard feynman's book 'Quantum mechanics and path integrals' since this suggests the universe oberys determinism but i thought that this was not the general belief to quantum physicists. Please could someone clarify this since i don't want to include such a statement when it is clearly a very contentious thing to state. Many thanks again

Roberto
 
Ive decided the word evolution is more appropriate than trajectory, but id still like to know if it is correct to say that a gigantic wavefunction could suggest determinism?? please if anyyone could help me please?
Thanks
 
The wave function and path integrals provide determinism of probability amplitudes. However, since they determine probabilities, it is possible that not EVERYTHING is deterministic. Yet, there is a possibility that they also determine something else, like Bohmian particle trajectories. In this case everything is deterministic.
 

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