Does the universe have a centre of gravity?

Question

or is everywhere or nowhere the centre?

Answer 1

Of all the objects in the universe, there must be a center of gravity that applies to the total mass.

Answer 2

The "Big Bang" is the predominant theory of the creation of the universe. It states that about 13.7 billion years ago the universe suddenly expanded from a point. At first the rate of expansion was enormous, but after several seconds it slowed. Today we can measure that all of the major objects in the universe are expanding outward, and the farther out they are the faster they are expanding. Hubble showed this in the early 20th century. In the 1990s, further measurements by teams observing supernovae at huge distances showed that the expansion is actually increasing! This suggests the existance of a previously unknown force. This force has been named "Dark Energy" and little is known of it other than the fact that the expansion is increasing.
Addressing your question about the center of gravity of the universe, there is a really strange effect! The expansion is not just the objects moving away from each other, but rather space itself is expanding! At every object, such as the earth, it seems that everything is moving away. A popular analogy is made by imagining dots painted on a balloon. When the balloon inflates every dot "sees" every other dot moving away from it. On the surface of that balloon, there is no center since every point is the same as every other point on the surface of a sphere. The expansion of the balloon is in a third dimension - a dimension perpendicular to the surface. Likewise, the expansion of our universe is in another dimension. This does not seem to make sense but there are lots of measurements and data to support it.
So, just as on out imaginary balloon's surface there is no center, so in our universe there is no center in the 4 dimensions we're familiar with, and therefor no center of gravity

Answer 3

Well, in an infinite universe, there is no center. In a finite universe, there may be a center. Current models of galactic superclusters indicate some sort of Great Attractor towards Centaurus, I believe. Large superclusters appear to gravitate towards this anomaly. This might be considered a "center" so to speak.
Proponents of the Big Bang theory should know that there is no center, as all of space expanded from a singularity, and is space itself that is expanding not the objects within. You could say that we are the center of the Universe because everything is accelerating away from us by this logic, but in the theory supposes the same observation is made from any given galaxy.

Answer 4

If the universe is infinite, then yes, there is a center of gravity. If the universe is finite, but not wrapped back on itself, then yes there is a center of gravity. If the universe is finite, and wrapped back on itself (think "sphere"), then it does not contain a center of gravity.

In the last, one could imagine a center of gravity existing outside of that universe (whatever that might mean physically), but note that that universe would not contain any center of gravity.

Answer 5

Yes. The Universe has a center of gravity. However, the center of gravity is anologous to that of our solar system, which is not an absolute geometrical point which is immobile , but one that continuously moves in a three dimensional patern.

Answer 6

The site below from the Univ. of California at Riverside argues that, according to current theory, there is no "center."

http://math.ucr.edu/home/baez/physics/Relativity/GR/centre.html

--Bill Pardue, Reference Librarian
Arlington Heights Memorial Library
Find your local library at:
http://lists.webjunction.org/libweb/Public_main.html

Answer 7

Yes. The center-of-gravity is an equation for all of the masses. But what if the center-of-gravity is on the center-of- antigravity...

Answer 8

Yes.

Answer 9

it's a chain of fractals, it just goes everywhere in every direction.

Answer 10

You have the big bang, if there is a big bang