Scenario takes the present acceleration of the expansion of the universe to extremes. In the wake of observations of distant supernovae (see the article by Saul Perlmutter in Physics Today, April 2003, page 53), cosmologists generally apportion 70% of the universe’s energy inventory to an enigmatic dark energy. The new relevant parameter, which must be less than —1/3, is w, the ratio of the dark energy’s average pressure to its energy density. The widely known cosmological-constant and quintessence models explore values of w between —1/3 and —1. But what if w is less than —1? In that “phantom energy” case, Dartmouth College physicist Robert Caldwell with Marc Kamionkowski and Nevin Weinberg of Caltech have now determined that eventually all bound objects—galaxies, stars, planets, atoms, nuclei, and nucleons—will be torn apart. Caldwell suggests that deciding between their model and the others might be possible in coming years with...
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1 October 2003
October 01 2003
The big rip: A new cosmic doomsday
Physics Today 56 (10), 9 (2003);