What is Quantum: Definition and 999 Discussions

In physics, a quantum (plural quanta) is the minimum amount of any physical entity (physical property) involved in an interaction. The fundamental notion that a physical property can be "quantized" is referred to as "the hypothesis of quantization". This means that the magnitude of the physical property can take on only discrete values consisting of integer multiples of one quantum.
For example, a photon is a single quantum of light (or of any other form of electromagnetic radiation). Similarly, the energy of an electron bound within an atom is quantized and can exist only in certain discrete values. (Atoms and matter in general are stable because electrons can exist only at discrete energy levels within an atom.) Quantization is one of the foundations of the much broader physics of quantum mechanics. Quantization of energy and its influence on how energy and matter interact (quantum electrodynamics) is part of the fundamental framework for understanding and describing nature.

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  1. P

    I How does the quantum of action cause indeterminism?

    How and/or why does the existence of the quantum of action (Planck's constant) cause indeterminism?
  2. S

    I Measure of existence? (Stanford Encyclopedia of Philosophy)

    I'm reading the article on the Many Worlds Interpretation in the Stanford Encyclopedia of Philosophy. I'm keeping up well, but this excerpt uses things I'm very unfamiliar with: I guess some characters weren't recognized. It's Section 3.6 here. I'm somewhat familiar with Wigner's Friend, but...
  3. jjson775

    I Why do exponential functions occur outside of finite walls?

    Between the walls of a finite well, the solution to the time independent Schrodinger equation is a combination of sines and cosines. Outside the walls where E - Uo is positive, the solutions are exponential functions. Why?
  4. H

    Comp Sci Quantum computing circuit for qubits equality

    This is the given circuit: I think to add another Cnot on the right with a1 as control and a0 as target, to set initial states of a0 an a1 both |0⟩, and to measure the a0. If a0=|0⟩ then b0=b1, and vice versa. Is it correct?
  5. Kennard Callender

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  6. MarkVII

    Quantum Hip: The Latest Scientific Frontier

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  7. Donut

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  8. cathrynliz

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  9. okaythanksbud

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  10. Sr1

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  11. R

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  12. P

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  13. L

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  14. A

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  15. E

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  16. ramana3797

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  18. N

    How Does Quantum Mechanics Mirror Alice and Bob's Adventure?

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  19. immortalsameer13

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  20. RobbyQ

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  21. B

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  22. ohwilleke

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  23. J

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  24. .Scott

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  25. RobbyQ

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  26. A

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  27. A

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  28. T

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  29. jaketodd

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  30. sophiecentaur

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  31. L

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  32. 4

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  33. L

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  34. Demystifier

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  35. P

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  36. shunyadragonvv

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  37. StenEdeback

    Classical Looking for book about relativistic classical field theory

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  38. Bertin

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  39. Halc

    I Do black holes destroy quantum states?

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  40. giodude

    I Quantum Entanglement and Parallel Worlds/Existence

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  41. hachi44

    I Principles of Quantum Mechanics - Hans C. Ohanian - 0137127952

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  43. P

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  44. L

    B Quantum Computers and their special properties?

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  45. Muu9

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  46. L

    B Quantum Entanglement & Hybridization

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  47. F

    B Quantum entanglement and simultaneity

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  48. Y

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  49. cwill53

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  50. D

    B Does anything happen in the quantum world?

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