Without saying so all of the solutions to Einstein's equations come from or lead to singularities, or do both. In all these solutions the cosmological constant is taken to be zero. Einstein had suggested that it was not zero and of just the right sign and magnitude to make the universe stable.

Since astronomical observation suggests that the universe is flat and expanding, it is now presumed that it is the initial condition of a singularity that fits General Relativity to our universe. Hence the origin of the concept of the Big Bang, rather than the Big Crunch.

However, very recent data indicates that the expansion is accelerating, suggesting that the cosmological constant is indeed non-zero, but of the opposite sign from what Einstein suggested.

Also, the Big Bang is not in reality a singularity as singularities cannot exist in nature, contrary to DrDick's opinion. It is more likely that this universe came from a mother universe. Smolin, Greene and the Russian guy who did inflation theory, now at Stanford (cannot remember his name) have all proposed physics theories for the birth of our universe. Then there is the cyclic universe theory as well.


All this comes from my head. I do not have to copy it from some site as you have to.

You do not seem to be able to figure me out. However, we have all figured you out.

• Twit - carefuluniverse - November 26, 2002 - 19:30 UTC
  • And apparently you don't approve of reading books. - yaniru - November 27, 2002 - 03:10 UTC
    • nt - quiet - November 27, 2002 - 04:46 UTC
• Its the same sign that Einstein suggested... - bruce - November 27, 2002 - 01:34 UTC
  • His theory does not predict that - yaniru - November 27, 2002 - 03:12 UTC
    • Sorry Bruce - yaniru - November 27, 2002 - 03:15 UTC
  • I think it's negative - yaniru - November 27, 2002 - 12:31 UTC