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On Thought Experiments: Question

  1. Feb 16, 2012 #1
    Hello friends,

    I woke up this morning with a thought that would not leave me alone. I have been thinking about it and it could be my lack of conceptual understanding of thought experiments and perhaps even quantum physics, but here it is: what is the importance of thought experiments, specifically Schrodinger's Cat and Quantum Suicide? I even impose the "so what?" for them, not out of ignorance but out of wonder. What are their use to people who aren't physicists?
  2. jcsd
  3. Feb 16, 2012 #2


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    Thought experiments are experiments which we think out in our minds and discuss because they are either impractical or sometimes impossible to do in real life. Thought experiments are useful for a variety of reasons.

    1) Einstein used thought experiments to prompt him on the path to the development of both SR and GR. He imagined, for example, what it would be like to just float in space versus freefall on Earth (e.g. on a dropping elevator). These experiments were impractical to perform during his time, so he had to use his imagination to help guide him where to go.

    2) Schroedinger used his cat thought experiment to try to show the "insanity" of the basic axioms of quantum mechanics. The Schroedinger's cat experiment is an attempt at "reductio ad absurdium". Obviously, it's absurd for a cat to be "in a superposition of alive and dead", so one has an apparent paradox in that although QM works well in the small scale, on the macro scales it appears to predict absurd results. In this way, Schroedinger tried to show that QM was fundamentally flawed. Maxwell's demon is another thought experiment which tries to show that the second law of thermodynamics is wrong.
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