Are Dark Matter and Dark Energy the New Epicycles?

An article in The Economist suggests that dark matter and dark energy may not be necessary to understand the structure of the universe.  It refers to two recent papers that explain the cosmic background radiation and galaxy clusters with ordinary matter, without a need for either of the other two unknown quantities.  Are dark matter and dark energy like the fudge factors called epicycles that Ptolemy used to keep his outdated cosmology working?  The article allows that, at this point, either side of the controversy could be wrong, but “On the other hand, a universe that requires three completely different sorts of stuff to explain its essence does have a whiff of epicycles about it. … one cannot help but wonder whether Ptolemy might soon have some company in the annals of convoluted, discarded theories.”

Dark energy is the big fad these days.  Leading cosmologists are certain they have proved its existence in this era of “precision cosmology” (see 06/20/03).  A model that doesn’t rely on 96% unknown entities would seem to have a built-in advantage.  Let’s watch to see who eats crow a few years from now.