You have to understand the origin of this thread.

Someone claimed that the universe has a center of mass.

Others like JP and Alex saidno.

I said that there is a center of mass of the visible universe. And in addition, because gravitons travel at the speed of light, we only feel the gravity of essentially what we can see, plus all the intervening dark matter of course.

The discussion then diverged into whether or not the universe is uniform. If unifvorm then the center of mass correspondes to the location of the observer. I claimed nonuniformity on all scales that we can see and used Geller's galactic maps as evidence.

They seemed to say that the uniformity exists at larger scales. I agreed except that those scales are larger than 30 billion light-years and we cannot feel the effects of the gravity of those scales. So they in a gravitational sense do not contribute to the center of mass.

Thank you for the opportunity to sum up the arguments. Afterall its Harvard against Utah & Russia.

• You've been informed what large structure is.. - bruce - March 28, 2001 - 01:23 UTC
  • I confess - yanniru - March 28, 2001 - 15:39 UTC
• Gravity - egauldin - March 28, 2001 - 02:42 UTC
  • Welcome back - yanniru - March 28, 2001 - 13:06 UTC
  • Yes, gravitation propagates with c - alexander - March 29, 2001 - 19:07 UTC