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Q & A: dark energy and planets

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Most recent answer: 10/22/2007
Q:
Does dark energy play a part in binding planets in their orbits?
- Brad (age 32)
Bakersfield,CA
A:
We don't think that dark energy plays any noticable role in planetary motion. It does seem to be driving an acceleration of the rate of expansion of the universe, but on the scale of galaxies or smaller, that effect doesn't significantly change the shorter-range effects holding things together.

In the long run, understanding dark energy may be connected to unraveling other deep puzzles needed to figure out why physics looks anything like the way it does, but meanwhile you can calculate planetary motion fairly well using Newtonian physics, and very very well using General Relativity.

Mike W.

(published on 10/22/2007)

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