What is the value, in joules, of one quantum of energy?

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Discussion Overview

The discussion revolves around the value of one quantum of energy, specifically questioning whether it is equivalent to Planck's constant and exploring the implications of quantization in physics. The scope includes theoretical considerations and conceptual clarifications related to quantum mechanics and energy quantization.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • Some participants assert that Planck's constant (h) is not a measure of energy but rather a quantum of action, with energy for a photon defined as E=h*nu, suggesting that energy can be arbitrarily small for low-frequency photons.
  • One participant proposes that in a continuous space, energy eigenvalues can form a continuum, indicating no smallest unit of energy for free particles, while questioning the implications of quantizing space.
  • Another participant suggests that if space could be quantized, one might define a smallest unit of energy based on the movement of the lightest particle over minimal distances and time.
  • Concerns are raised about the terminology of quantum mechanics, noting that it produces bands of energy in materials, which implies a continuous range of energy states rather than discrete units.
  • Some participants challenge the assumptions of continuous energy bands in condensed matter physics, suggesting that real systems may involve complexities that lead to coarse graining effects.

Areas of Agreement / Disagreement

Participants express differing views on the nature of energy quantization and the implications of quantum mechanics, with no consensus reached on the definition of a quantum of energy or the validity of the terminology used in quantum mechanics.

Contextual Notes

There are unresolved assumptions regarding the quantization of space, time, and energy, as well as the implications of continuous versus discrete energy states in quantum mechanics.

JDude13
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What is the value, in joules, of one quantum of energy?
I read somewhere that it is equal to h (Planck's Constant). How much merit does this information hold?
 
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JDude13 said:
What is the value, in joules, of one quantum of energy?
I read somewhere that it is equal to h (Planck's Constant). How much merit does this information hold?

None.

h is the quantum of action, which does not have the units of energy.
For a photon of frequency nu, the quantum of energy is E=h*nu. Thus it can be arbitrarily small for sufficiently soft photons.
 
Well just take your Schrödinger Equation solution for a particle in a box of dimension L and let L go to infinity. Your energy eigenvalues becomes a continuum. There is really no notion of a "smallest" unit of energy of a free-particle, at least with continuous space. If one quantizes space you might get a smallest unit but I have no idea about that stuff.
 
If we could quantize space we could define it as half the energy it takes to move the particle with the least non-zero mass, the shortest non-zero distance in the shortest non-zero time.

If quantum mechanics is based on the fact that the universe can be quantized and we haven't quantised time, space, matter or energy yet... Why do we call it quantum mechanics?
 
JDude13 said:
If we could quantize space we could define it as half the energy it takes to move the particle with the least non-zero mass, the shortest non-zero distance in the shortest non-zero time.

If quantum mechanics is based on the fact that the universe can be quantized and we haven't quantised time, space, matter or energy yet... Why do we call it quantum mechanics?

This is puzzling. Quantum mechanics also produces BANDs of energy (i.e. a continuous range of energy) in matter that forms the conduction band, the valence band, etc. in metals, semiconductors, and insulators.

I suggest you stop getting hung up on the name, and learn the physics.

Zz.
 
ZapperZ said:
This is puzzling. Quantum mechanics also produces BANDs of energy (i.e. a continuous range of energy) in matter that forms the conduction band, the valence band, etc. in metals, semiconductors, and insulators.

I suggest you stop getting hung up on the name, and learn the physics.

Zz.

Although BANDS are only truly continuous within the unphysical assumptions of condensed matter on a lattice. Infinitely many periodic, perturbative potentials. To me I always assumed surface effects would produce some level of coarse graining in real systems.
 

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