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How the expansion of the universe doesn't violate the principle of the conservation of energy?

If we would put a spring between two objects, the distance would get bigger between them, so would the potential of the spring. And with objects with mass, the same goes for the gravitational potential energy between them...

What am I missing here? Where does this energy come from?


marked as duplicate by Kyle Oman, John Rennie, AccidentalFourierTransform, Qmechanic Apr 22 '16 at 9:23

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  • $\begingroup$ We don't know if it violates the conservation of energy and we don't know where the energy comes from if it doesn't. $\endgroup$ – CuriousOne Apr 21 '16 at 6:33
  • 3
    $\begingroup$ Possible duplicates: physics.stackexchange.com/q/2838/2451 and links therein. $\endgroup$ – Qmechanic Apr 21 '16 at 6:39

The initial energy to effectively fuel this expansion came from the Big Bang. Energy is not then continuously required to fuel further expansion. The temperature of the universe may decrease due to expansion, but the rate of expansion is accelerating due to currently unobserved dark energy, according to common theory. If the repulsive forces from the dark energy are not considered, the expansion would have probably stopped, come to a negligible rate, or the universe may have started contracting.

  • $\begingroup$ Do you mean dark energy? $\endgroup$ – velut luna Apr 21 '16 at 8:41

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