DesertFox
08-31-2007, 08:11 PM
Dark energy may not be needed to explain why the expansion of space appears to be speeding up. If our universe is like Swiss cheese on large scales – with dense regions of matter and holes with little or no matter – it could at least partly mimic the effects of dark energy, suggests a controversial new model of the universe.
In 1998, astronomers found that distant supernovae were dimmer, and thus farther away, than expected. This suggested the expansion of the universe was accelerating as a result of a mysterious entity dubbed dark energy, which appears to make up 73% of the universe.
But trying to pin down the nature of dark energy has proven extremely difficult. Theories of particle physics suggest that space does have an inherent energy, but this energy is about 10120 times greater than what is actually observed.
More (http://space.newscientist.com/article/dn12574-swiss-cheese-universe-challenges-dark-energy.html)
In 1998, astronomers found that distant supernovae were dimmer, and thus farther away, than expected. This suggested the expansion of the universe was accelerating as a result of a mysterious entity dubbed dark energy, which appears to make up 73% of the universe.
But trying to pin down the nature of dark energy has proven extremely difficult. Theories of particle physics suggest that space does have an inherent energy, but this energy is about 10120 times greater than what is actually observed.
More (http://space.newscientist.com/article/dn12574-swiss-cheese-universe-challenges-dark-energy.html)