Gedankenexperiment

However, the subject need not be an esoteric one for a gedankenexperiment to be fruitful. My own favorite is Galileo’s proof that, contrary to Aristotle’s view, objects of different mass fall in a vacuum with the same acceleration. One might think that a real experiment needs to be conducted to test that hypothesis, but Galileo simply asked us to consider a large and a small stone tied together by a very light string. If Aristotle was right, the large stone should speed up the smaller one...