Wave function collapse Definition and 88 Threads

In quantum mechanics, wave function collapse occurs when a wave function—initially in a superposition of several eigenstates—reduces to a single eigenstate due to interaction with the external world. This interaction is called an "observation". It is the essence of a measurement in quantum mechanics which connects the wave function with classical observables like position and momentum. Collapse is one of two processes by which quantum systems evolve in time; the other is the continuous evolution via the Schrödinger equation. Collapse is a black box for a thermodynamically irreversible interaction with a classical environment. Calculations of quantum decoherence show that when a quantum system interacts with the environment, the superpositions apparently reduce to mixtures of classical alternatives. Significantly, the combined wave function of the system and environment continue to obey the Schrödinger equation. More importantly, this is not enough to explain wave function collapse, as decoherence does not reduce it to a single eigenstate.Historically Werner Heisenberg was the first to use the idea of wave function reduction to explain quantum measurement.

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  1. Musti425

    B Can someone please explain to me the motion of an electron?

    Hello everyone. I am not a physics major or anything but have recently started finding it very fascinating and have been reading up on some of physics most popular experiments. I recently started reading about the double slit experiment to learn more about QM concepts like wave particle...
  2. B

    I Wave function collapse in the early Universe

    If the wave function collapse is real then what in the very early universe caused the wave functions to collapse into particles since there were no observers? There were not even particles, just a impossibly hot 'soup' of nothing. So what created them?
  3. J

    B New hypothesis of continuous wave function collapse

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  4. Y

    I Collapse of particle wave function and single Universe wave function?

    Hi All, Sorry for a silly question from a curious but not properly initiated: why a concept of a particle wave function "collapse" upon "observing" even a thing given that there is only one Universe wave function that this particle is a part of? As I understand this, once a particle has...
  5. zaramahdi

    A Can particles appear and disappear "with" a cause?

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  6. P

    I How non-conscious can an Observer be and cause wave function collapse?

    Please help me find websites describing easy to understand experiments discovering how little of a Conscious Observer is needed to cause wave function collapse? Is just a sensor, that "could have been" attached to a reporting device, that "could have been" looked-at by a Conscious Human...
  7. S

    I Exploring Wave Function Collapse: The Role of Conscious Observation

    Do scientists still entertain the idea that wave function collapse requires a conscious observer? Is it possible? Why/not?
  8. B

    Decoherence vs Observer Wave Function Collapse & MWI: Questions

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  9. lektroon

    I Are Nicolas Gisin's Intuitionist Mathematics Theories Compatible with SR and GR?

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  10. C

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  11. E

    B Question about quantum superposition

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  12. B

    B Entangled particle decoherence question

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  13. TheHeraclitus

    B Objective-collapse theory, collapse for large objects

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  14. Sciencemaster

    I Exploring Wave Function Collapse and Measuring Particles

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  15. O

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  16. Lexovix

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  17. hyksos

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  18. Sciencemaster

    I Does the wave function spread more quickly after it is observed?

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  19. danielhaish

    I Why quantum wave function collapse is not consider a signal?

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  20. StevieTNZ

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  23. Sophrosyne

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  24. Silvio Macedo

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  25. T

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  26. Sandeep T S

    I Wave function collapse in a double slit experiment

    Is anyone did experiment on wave function collapse in double slit experiment. Could you please share information about that, and also share research paper about that experiment. What kind of observation done here, what kind of equipment used for that?
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  28. J

    I Would this experiment prove consciousness causes collapse

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  29. D

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  31. E

    I Wave function collapse and measurement rule

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  32. Thejas15101998

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  34. P

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  35. ohwilleke

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  36. M

    I Trying to model wave function collapse

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  37. J

    B Measuring velocity and interference?

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  38. J

    B How does sideband detection work in a Penning trap?

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  39. N

    B Interference pattern after a particle is detected?

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  40. FreeThinking

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  41. E

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  42. I

    B Is the wave function collapse asymmetrical in time?

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  43. Bill Myk

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  44. P

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  45. Hybrid

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  46. Hybrid

    I Many Worlds - Superdeterministic?

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  47. abrogard

    B What Is Surprising About Wave Function Collapse?

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  48. H

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  49. B

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  50. C

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