The ultimate fate of the universe??

Question

In terms of the size and future of the universe, could someone explainto me, in simple terms, the concepts of a closed, flat, and an openuniverse? Am I correct in believing they refer to whether the universeis expanding, and at what rate, and to the ultimate fate of the
universe?

Answer 1

You're mostly correct! There's a contest going on between the
expansion of the universe, started by the big bang, and gravity, which is trying to stop it. There are three possibilities:- if there's enough mass/energy then gravity wins, the expansion will stop, and the universe will collapse in on itself -"The Big Crunch". The universe is "closed". If there isn't enough mass/energy the big bang wins and the expansion goes on forever. The universe is "open". The third possibility is that the amount of mass/energy is just enough to stopdrawing *really big* triangles - wherever you happened to be they'd look flat, but because they're drawn on the Earth's surface they're really closed. You'd only find that out by measuring the angles. Now imagine drawing triangles on a cosmic scale. If the universe isn't flat, the angles wont add up to 180! Drawing them on that scale is obviously impossible, but by looking at the results of cosmic microwave background experiments like COBE and Boomerang we can see other indications that the universe is flat.

Until the late 1990s it was thought that the ultimate fate of the
universe was indicated by its shape. Along came the discovery of dark energy, and we now have the possibility that the expansion of the universe will accelerate to the point where it's torn apart! Welivein interesting times!

Answer 2

Sort of.

Open, flat and closed refer actually to the matter and energy density in the universe. The simplified version is that if there is very little matter in the universe, its space-time shape is "open." The 2-D analogy is the infinite-area saddle-shaped surface. If there is a lot of matter in the universe, its space time shape is "closed." The 2-D analogy is a finite-area sphere. If there is just the right amount in between, the space-time shape is "flat."

These descriptions tell you what happens if you shine two light beams parallel to each other. Essentially, they will stay parallel forever in a flat universe, but they will converge eventually in a closed universe and diverge in an open universe.

Of course, the amount of matter in the universe indirectly will affect how and how fast the universe expands. In theory, a "closed" universe has enough matter to eventually stop the expansion and cause a contraction into a "Big Crunch." a flat or open universe does not, and the universe will expand forever.

However, these conclusions may be inaccurate with more recent developments. Additional complications, like the "inflationary" model (where there is a period of brief or even continuous "inflation" caused by a breaking of symmetry), may mean the universe will expand forever even in a closed universe.

For more info, consider reading Brian Greene's "The Elegant Universe."

Answer 3

Current calculations suggest that the universe will continue to expand "forever" (the "open universe" model), since there is insufficient mass/gravity to slow and ultimately reverse its expansion (so that it would end in a "Big Crunch", the "closed universe" model). What this means is that eventually everything will be so far apart, the whole universe will cool down until it all approaches 0 Kelvin, stops moving, and ceases to exist with a whimper, rather than a bang. (with apologies to T.S.Elliot)

This wiki might help:

http://en.wikipedia.org/wiki/Ultimate_fate_of_the_universe

Answer 4

Galaxies are end stages in the evolution of the universe.
The farthest galaxies you can see don't exist to-day.
The universe is expanding but the expansion stops as galaxies annihilate themselves.
The end of a galaxy is recorded as a seconds long gamma ray burst.
The milky way will suffer the same fate sometime in the future.
Eventually the universe itself will go out of existence.

Answer 5

Hi. A closed universe would expand and contract over a very long time. A flat universe would be static. An open universe would expand forever.

Answer 6

nicely there is sound theory to the massive Bang theory. yet technological information has did not comprehend how the universe could end the massive Crunch theory replaced right into a failure. the massive Rip theory and the massive Freeze theory brought about a divide between scientists.