Does the unobserved past exist in a super position in the sense of quantum mechanics? Has anyone seen this question asked before? If the question is meaningful, what answer seems most likely. If the question is not meaningful, where does it fail? Is it possible details of the big bang, including whether there was a big bang as opposed to a different origin of the universe that many potential answers exist in a super position, that will not collapse until an observation suitable to cause it's wave function to collapse is made?

  • The unobserved past existed in a superposition. Superpositions (in the wave function) evolve according to the Schrödinger's equation even without collapse, so the past is gone, observed or unobserved. "Many potential answers" do exist before collapse, but they are not frozen in time due to non-observation.
    – Conifold
    Commented Nov 16, 2023 at 2:02
  • what do you mean by "unobserved" ? If it's "events" that nobody saw, like Earth before the apparition of life, it's not what quantum physics superposition and collapse are about.
    – armand
    Commented Nov 16, 2023 at 4:59
  • Please clarify the long sentence "Is it possible details ..." from the second part of your question.
    – Jo Wehler
    Commented Nov 16, 2023 at 6:01
  • Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.
    – Meanach
    Commented Nov 16, 2023 at 8:04

1 Answer 1


It's an intriguing idea but sadly it isn't really compatible with current mainstream physics. You might have picked up the idea of an 'observer' from accounts of quantum theory, in some of which 'observers' and 'measurements' play a special role. However, there is no need to invoke either role, generally speaking, when you are talking about reality on a macroscopic scale. Our daily life on Earth goes on regardless of whether anyone is making observations or measurements in the sense adopted in quantum theory. Finally, the wave functions of quantum theory are always superpositions of one sort or another, so in general there isn't anything remarkable about a superposition- it just means that you can always express a wave function as a blend of other wave functions.

  • Thanks for the reply. Yes, I do realize that quantum effects are not considered to be seen on the macro scale, but I do not find the evidence convincing me yet. For instance openAI estimates for me, the number of protons in 90 kg of iron is 9.713 times 10 to the 26th. And I suspect if we could actually calculate the what quantum theory tells us that 1 second later over 99.9999% of its particles with over 99.999% probability would be where we observed them before. If we actually lost a few billion subatomic particles due to quantum effects, I doubt we'd notice. So I am not convinced yet. Commented Nov 18, 2023 at 17:44

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