Macroscopic object wave function

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Discussion Overview

The discussion centers on the wave function of macroscopic objects, particularly in relation to their de Broglie wavelength and the implications for understanding quantum mechanics at larger scales. Participants explore theoretical frameworks, analogies, and the relationship between the wave functions of constituent particles and the overall wave function of the composite object.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants propose that the wave function of a large object can be understood as a result of the wave functions of its constituent particles, with the de Broglie wavelength serving as an approximation under certain conditions.
  • Others argue that the de Broglie wavelength is a very approximate tool and that the quantum function of a large object may be visualized as being "pinned" by individual particles, with the rigidity of this pinning related to particle momentum.
  • A participant references the Bohr Correspondence Principle, suggesting that a large number of atoms leads to behavior consistent with Newtonian mechanics.
  • There is a question regarding the proof of the correctness of the de Broglie wavelength for macroscopic objects, with a request for references on the subject.
  • Another participant inquires whether theorists have comprehended how a wave function with a small wavelength can emerge from the wave functions of smaller particles, reiterating this question in multiple posts.
  • A participant shares a paper that discusses representing N particle positions with a center-of-mass position and relative positions, suggesting this framework explains the small wavelength of the center of mass due to its large mass.

Areas of Agreement / Disagreement

Participants express differing views on the interpretation of the de Broglie wavelength in relation to macroscopic objects, with no consensus reached on the underlying theoretical framework or the validity of the approximations used.

Contextual Notes

Some limitations include the dependence on specific definitions of wave functions, the unresolved nature of the mathematical steps involved in deriving the de Broglie wavelength for macroscopic objects, and the varying interpretations of the relationship between quantum mechanics and classical mechanics.

fhenryco
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A composite object made of many atoms has a large mass hence a small de Broglie wavethength...and we know that recent experiments succeeded to obtain interference patterns even for such objects (for instance the C60 molecule). Did theoretician understood how a wavefunction with such a small wavelength could arise from the wave functions of the smaller particles inside the macroscopic objects that have larger wavethengthes ? Or is the wavefunction of the big object just a kind of heuristic tool that no one should try to understand in term of the subparts wavefuntions ?
 
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De Broglie wavethength is very approximate tool.
The quantum function of large (heavy) object can be visualized as "pinned" (i.e. constrained) by each particle, with each pinning "rigidity" proportional to particle impulse, producing something resembling wavelet. De Broglie wavethength is approximation for the total wavelet size when it is much larger than distance between individual particles. At higher impulses, large object is better described as just sum of wavefunctions of constituent particles.
 
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The Bohr Correspondence Principle says that large number of atoms approaches Newtonian Mechanics.
 
trurle said:
De Broglie wavethength is very approximate tool.
The quantum function of large (heavy) object can be visualized as "pinned" (i.e. constrained) by each particle, with each pinning "rigidity" proportional to particle impulse, producing something resembling wavelet. De Broglie wavethength is approximation for the total wavelet size when it is much larger than distance between individual particles. At higher impulses, large object is better described as just sum of wavefunctions of constituent particles.
Thanks ! very interesting, Would you have a reference on the subject ?
 
Is there proof of the correctness of the de Broglie wavelength for macroscopic objects?
The proof based on the analogy with light for elementary particles is familiar to me.
 
fhenryco said:
Did theoretician understood how a wavefunction with such a small wavelength could arise from the wave functions of the smaller particles inside the macroscopic objects that have larger wavethengthes ?
See my paper https://arxiv.org/abs/1406.3221 Sec. 2. The idea is to represent N particle positions by one center-of-mass position and N-1 relative positions. The center of mass has a large mass (the sum of all individual masses), so it has a small wavelength.
 
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