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Intuition for General/Special Relativity theorems without experiments

  1. Aug 16, 2012 #1
    I am not a mathematician, so I always used to wonder about following.

    "I never heard Einstein conducting any experiments, But how he predicted the physics properties the way it is explained in Relativity Theorems. These are some of the breakthroughs of that time, But without the intuition from the experiments how Relativity Theorems are developed? "

    At the same time, How it required experiments to develop the theories related to invention of the transistor, Like a new branch of Quantum Psychics to account for the odds they observed.

    How theoretical physics related to practical physics, how they evolve ?
    Can anyone point me to the resources to develop this mathematical intuition.
    I could be asking a totally stupid question here.
  2. jcsd
  3. Aug 16, 2012 #2


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    There were many experiments involved in Einstein's theories.

    In special relativity, he used the fact that you can drink coffee in an aeroplane just the same as you were stationary on the ground. He assumed this is true for all speeds. This is the "Principle of Relativity".

    In general relativity, he used the fact that different materials of different masses always fall to the ground at the same time. This is worked into his "Principle of Equivalence"

    So Einstein used old experiments that everyone can do, and built his theories by assuming that these old experimental facts could be generalized to very high speeds, or to very strong gravitational fields.

    Apart from the Principle of Relativity, Einstein also used Maxwell's equations, which are based on experiments by Ampere, Faraday etc.
  4. Aug 18, 2012 #3
    Thanks for your reply, I am checking along your lines.
    Can you give some resources, so it is quite clear on how developed those theorems.
    AFAIK, The ampere and faraday experiments are quite a lot simple compared to these theorems.

    The question still didn't quite answered.
    Especially about the theoretical and practical, if there is such distinction in the first place.
  5. Aug 18, 2012 #4


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    As long as Einstein read the results of experiments performed by other people, he didn't necessarily have to do them himself. This is the theorist / experimentalist split.

    I don't think Einstein focused on reading experimental results from all reports (I'm not a historian), but he was aware enough of them to abandon theories that did not agree with experiment.

    If a theorist gets totally cut off from experiment, they'll become unprodctive in developing theories that will be ignored because they are known to be wrong because they don't agree with measurments.
  6. Aug 21, 2012 #5
    I am reading a paper by Dirac from 1931, in which he showed that it is necessary for there to be magnetic monopoles if electric charge is quantized.
    It requires some mathematical facility, but he is very good at explaining his thoughts, and the whole point rests on a thought experiment.
    He also explains a lot of why modern physics gets so far into abstract math.
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