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Question about a quote I heard

  1. Mar 11, 2013 #1
    A long time ago I heard a quote that went along the lines of "if we knew the location and velocity of every particle in the universe we could predict every action and reaction from now until the end of time." I'm thinking this idea may have come from Issac Newton as his third law would seem to have a connection it.

    My question is if any of you know where this quote/idea originated from? I'd like to use the idea in a personal project of mine but have no where to source it from.

    I would really appreciate any help with this.
  2. jcsd
  3. Mar 11, 2013 #2


    Staff: Mentor

  4. Mar 11, 2013 #3
    In 1814, Laplace published what is usually known as the first articulation of causal or scientific determinism:[39]

    We may regard the present state of the universe as the effect of its past and the cause of its future. An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atom; for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes.

    —Pierre Simon Laplace, A Philosophical Essay on Probabilities[40]
  5. Mar 11, 2013 #4


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    Staff Emeritus
    Science Advisor

    Note that in the light of Quantum Mechanics this quote isn't accurate anymore.
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