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, and the smaller one retard the larger one, if they fall at different rates. However, if you let the string length approach zero, you have a single object with a mass equal to the sum of their masses, and hence it should fall at a higher rate than either. This is nonsensical. The conclusion is that all objects fall in a vacuum at the same rate.


Gino Segre on the importance and validity of "thought-experiments," using Galileo's disproof of objects falling at different rates as an example.

Folksonomies: thought experiment testability

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/science/social science/philosophy/ethics (0.435433)
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Galileo:Person (0.973169 (negative:-0.335207)), Gino Segre:Person (0.641518 (positive:0.355749)), Aristotle:Person (0.549719 (neutral:0.000000))

Classical mechanics (0.908648): dbpedia | freebase
Logic (0.861838): dbpedia | freebase | opencyc
Object (0.788305): dbpedia | freebase
Theory (0.772680): dbpedia | freebase
Mass (0.723270): dbpedia | freebase | opencyc
Psychology (0.706637): dbpedia | freebase | opencyc
Thought experiment (0.683039): dbpedia | freebase | yago
ASCII (0.671900): dbpedia | freebase | opencyc | yago

 This Will Make You Smarter
Books, Brochures, and Chapters>Book:  Brockman , John (2012-02-14), This Will Make You Smarter, HarperCollins, Retrieved on 2013-12-19
  • Source Material []
  • Folksonomies: science


    19 DEC 2013

     The Cognitive Toolbox

    Memes that would make good index cards for a box of important cognitive ideas.