Are Elementary Particles Distinguishable?

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Discussion Overview

The discussion revolves around the distinguishability of elementary particles within the framework of quantum theory. Participants explore the implications of objective existence and the mathematical descriptions of indistinguishability in quantum statistics, as well as specific examples from quasicrystals and their relevance to the topic.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants argue that the objective existence of elementary particles implies they must be distinguishable, while others challenge this notion based on quantum statistics.
  • One participant notes that the term "distinguishable" has a specific meaning in quantum statistics, particularly in relation to Fermi-Dirac and Bose-Einstein statistics.
  • A participant provides an example involving quasicrystals, suggesting that atoms in such structures can be viewed as distinguishable due to their unique positions in a quasiperiodic grid.
  • Another participant questions the validity of the example provided, asserting that it contradicts the indistinguishability of electrons as described by Fermi-Dirac statistics.
  • There is a reference to a paper by one participant, which they claim supports their argument, but another participant disputes the interpretation of this reference.
  • Concerns are raised about the appropriateness of using arXiv as a reference compared to peer-reviewed journals.

Areas of Agreement / Disagreement

Participants express differing views on the concept of distinguishability, with no consensus reached. The discussion remains unresolved, with competing interpretations of quantum statistics and the implications for elementary particles.

Contextual Notes

Participants highlight the limitations of definitions and the specific contexts in which terms like "distinguishable" are used, indicating a need for clarity in the discussion.

bilha nissenson
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The formulation of quantum theory does not comply with the notion of objective existence of elementary particles. Objective existence independent of observation implies the distinguishability of elementary particles. In other words: If elementary particles have an objective existence independent of observations, then they are distinguishable. Or if elementary particles are indistinguishable then matter cannot have existence independent of our observation.

so, what do you think? Are Elementary Particles Distinguishable?
 
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bilha nissenson said:
The formulation of quantum theory does not comply with the notion of objective existence of elementary particles. Objective existence independent of observation implies the distinguishability of elementary particles. In other words: If elementary particles have an objective existence independent of observations, then they are distinguishable. Or if elementary particles are indistinguishable then matter cannot have existence independent of our observation.

so, what do you think? Are Elementary Particles Distinguishable?

You are using the word "distinguishable" without realizing that that word has been "reserved" for a particular mathematical description within quantum statistics.

Would you like to use a specific example to illustrate what you mean?

Indistinguishibility within quantum statistics is what causes the Fermi-Dirac and Bose-Einsteins statistics. These have specific, unambiguous mathematical description. What you describe is a bit confusing, because I can distinguish a top quark from a bottom quark, and I can distinguish between a muon and a tau.

If you do not have specific physics to discuss here, then there's a possibility that this thread may be moved to the Philosophy forum.

Zz.
 
ZapperZ said:
You are using the word "distinguishable" without realizing that that word has been "reserved" for a particular mathematical description within quantum statistics.

Would you like to use a specific example to illustrate what you mean?

Indistinguishibility within quantum statistics is what causes the Fermi-Dirac and Bose-Einsteins statistics. These have specific, unambiguous mathematical description. What you describe is a bit confusing, because I can distinguish a top quark from a bottom quark, and I can distinguish between a muon and a tau.

If you do not have specific physics to discuss here, then there's a possibility that this thread may be moved to the Philosophy forum.

Zz.


one quantum specific example:

A quantum example for uniqueness of position

In Quasicrystals atoms are joined together in a long range order. One can visualize this order as Penrose tiling, where a shifted copy will never match exactly with its original. In such an order each intersection, which in quasicrystals marks the position of an atom, is a unique position upon an infinite grid, in that sense each atom have a unique position and in that sense is distinguishable. Atoms that form quasicrystals, (molecules), are quite heavy, and include at least thousands of elementary particles.
In their experiment, M. Torres and Al [11] have found out that the same order can be demonstrated for the electrons themselves:
“The spacing between the wave peaks (of the electron waves) was not constant, as in a periodic wave, but varied quasiperiodically between two values, which were related to the spacing in the pattern on the pan's bottom.”

Experiments revealing the exact circumstances for which a diffraction of quasicrystals disappear, by marking (with radioactive isotope etc.) very few atoms of the grid, might reveal information that will enable further understanding of the role of the unique position of each atom in the quasiperiodic grid. For observable results, doing the diffraction on the molecules as is done now would not be enough, what is needed is to get a refraction off the wave peaks as described in [11] but then how could we mark the electrons?
 
you could say that this is redundant, but I have a reply, so let me know.
 
bilha nissenson said:
one quantum specific example:

A quantum example for uniqueness of position

In Quasicrystals atoms are joined together in a long range order. One can visualize this order as Penrose tiling, where a shifted copy will never match exactly with its original. In such an order each intersection, which in quasicrystals marks the position of an atom, is a unique position upon an infinite grid, in that sense each atom have a unique position and in that sense is distinguishable. Atoms that form quasicrystals, (molecules), are quite heavy, and include at least thousands of elementary particles.
In their experiment, M. Torres and Al [11] have found out that the same order can be demonstrated for the electrons themselves:
“The spacing between the wave peaks (of the electron waves) was not constant, as in a periodic wave, but varied quasiperiodically between two values, which were related to the spacing in the pattern on the pan's bottom.”

Experiments revealing the exact circumstances for which a diffraction of quasicrystals disappear, by marking (with radioactive isotope etc.) very few atoms of the grid, might reveal information that will enable further understanding of the role of the unique position of each atom in the quasiperiodic grid. For observable results, doing the diffraction on the molecules as is done now would not be enough, what is needed is to get a refraction off the wave peaks as described in [11] but then how could we mark the electrons?

I just read this, and it makes no sense or connection as far as your faulty usage of the term "distinguishsibility". You STILL haven't addressed the fact that such a term has already been "reserved" for how one can exchange such particles in statistical mechanics.

If you are able to actually TRACK individual electrons having these "unique positions", I'd like to see it. This violates the indistinguishibility of Fermi-Dirac electrons within a solid. I'm willing to bet that you have misinterpreted this [11] paper, which you have conveniently omitted a full reference to. Where did you 'cut-and-paste' this from?

Zz.
 
bilha nissenson said:
have cut past it from my own article which by coincidence was published today,

http://arxiv.org/abs/0711.3539


I hate to burst your bubble, but appearing on arXiv isn't "publishing". Please note that we do not recommend using Arxiv extensively as a reference. We prefer the use of peer-reviewed journals. So to which journal did you submit this to?

You also haven't addressed the point that I made.

Zz.
 
Er... I should have put a bet on, because I was right. You misinterpreted your Ref. 11. by thinking that the Bloch wavefunction has anything to do with your quasicrystal. I strongly suggest that you first study off a solid state physics text before you apply something you do not understand.

I also recommend you re-read the https://www.physicsforums.com/showthread.php?t=5374" that you have agreed to. Pay particular attention to personal theory. This thread appears to be your attempt at discussing/advertising your paper that isn't peer-reviewed, and thus violates our rules.

Zz.
 
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