A Galaxy Too Far?

   Using the latest generation telescopes, new technologies such as 100 megapixel CCD cameras plus many new measurements on type 1a supernovas have conjointly made it possible  to conclude that the expansion of our universe is actually accelerating. Also evidence has been obtained for the existence of mysterious dark matter and dark energy components, the latter presently believed to account for more than two thirds of cosmic mass-energy.

   For the universe's most favored scenario today the picture has emerged of a flat universe having a Hubble constant of 72 (plus or minus 10%) and, including the effects of dark matter and dark energy, the time back to the Big Bang is put at 13.5 billion years, again with a 10% error range. Also the most accurately known oldest age for ancient stars in globular clusters now puts that age at about 12.5 billion years, again with an error range of 10 %. This result is a consistent picture having good agreement among the various cosmic chronometers. However, until dark energy is fully understood, the fate of our universe will remain uncertain.


References

R. Cowen, "Keck goes the distance." Science News, January 14, 1995.
Freedman, Wendy L. and M. S. Turner,
Sky and Telescope, Vol. 106, No. 4, 2004.

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