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Could "dark energy" be a sign of Earth's special place in the universe?

May 12, 2008

Ever since Copernicus placed the Sun at the center of the universe instead of the Earth, scientific discoveries have been repeatedly making our home planet less special and more ordinary. But could the "principle of mediocrity" turn out to be wrong in one critical recent discovery--dark energy (corrected, thanks to David's comment)--and could that discovery really mean something other than what physicists have suggested?

An article in the current Science News suggests an intriguing alternate interpretation. It begins:

For all the hand wringing among physicists about the nature of dark energy, the invisible stuff that appears to be revving up the rate of cosmic expansion, a nagging possibility remains. Dark energy could be a cosmic mirage — if humans live in a special place in the universe with a peculiar distribution of matter.

If Earth and its environs are centered in a vast, billion-light-year-long bubble, relatively free of matter, in turn surrounded by a massive, dense shell of material, then gravity’s tug would cause galaxies inside the void to hurtle toward the spherical concentration of mass, say theorists Robert Caldwell of Dartmouth College and Albert Stebbins of the Fermi National Accelerator Laboratory in Batavia, Ill. That process would mimic the action of dark energy — a local observer would be tricked into thinking that the universe’s expansion is accelerating.

The article makes me wonder what Joel R. Primack and Nancy Ellen Abrams, the authors of The View from the Center of the Universe: Discovering Our Extraordinary Place in the Cosmos might have to say about it. Perhaps I should have been less critical in my review of their book.