Sunday, February 19, 2012

The Economist regarding Cosmology:  Desperate times require desperate measures.

"More than any other scientific problem the cosmic-expansion conundrum presents scientists with an existential quandary.  'It could be a 22nd-century problem we stumbled upon in the 20th century,' says Dr. Turner.  Some researchers may begin to feel time would be better spent on other scientific pursuits."

The problem isn't quite clearly described. The original big bang notion postulated a constant expansion rate of the universe.  If we extrapolate backwards (using only the permissible terms) than we conclude that the universe is younger than the postulated ages for the stars.  The way to avoid this problem is to assume that things were expanding slower in the past with an accelerating expansion rate.  That requires energy, thus, the term Dark Energy.  All this has been repackaged to try avoiding the impression that cosmology is just a collection of kluges piled one upon another.

The article also notes that to achieve any consistency between the theory and observations that only 4% of the mass can be of the "known" sort, which includes stars, planets (and black holes) and the like.

"The puzzle was that various lines of evidence showed that the universe’s endowment of ordinary matter (the stuff that people, planets and stars are made of) would give it just 4% of that density."

The remaining 96% is called Dark Matter or Dark Energy, since Einstein defined a relation between mass and energy.  In the engineering universe where I live, we usually refer to these terms as "Error", but Dark Chocolate Fudge would satisfy me too.  Sometimes the Error is simply a missing term, but more often than not something was drastically wrong in the first place.

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