NASA: Evidence Favors Infinitely Expanding Universe

Chris Gondek writes "The Sydney Morning Herald has a story here about how NASA is expected to announce this week that it has proved the existence of "dark energy," a cosmic force that counteracts gravity and will keep the universe expanding forever. The announcement will effectively demolish the theory that life will be wiped out in a "big crunch" when the universe collapses, and should end decades of academic dispute. Scientists ranging from Stephen Hawking, the Cambridge University physicist, to Albert Einstein, have argued that the universe eventually will stop expanding and then implode under the force of gravity, destroying all life. The Chicago Sun Times has also got some info."

Comments

Re:Perception is reality

[KDan]

Expansion of the universe doesn't actually mean the space between the atoms in your body increases. The atoms in your body are tightly coupled by strong electromagnetic forces, which are stronger than the expansion of the universe. Imagine a cardboard disc on the elastic surface that usually represents spacetime - several cardboard discs will grow apart as you stretch the surface, but the discs themselves will not grow, they are rigid because of the internal forces.

Those discs are actually of sizes somewhere around clusters of (billions of) galaxies, so the atoms in your body are fairly safe.

Daniel

Re:Whew! That's a relief!

[Forgotten]

It's kind of a funny term. Heat death is actually the complete conversion of all the free energy in a system (in this case, of all systems) into the corresponding entropy. It's the victory of the second law of thermodynamics. It's not that all the energy goes away, but that it becomes so evenly spread that no further work is possible - there are no more free energy gradients to traverse. So it's not the death of heat, it's a death in heat - literally a tepid cosmos. ;)

As I noted in another message, an infinitely expanding universe means that the temperature of the heat-dead cosmos will constantly drop as the volume increases. It will asymptotically approach absolute zero.

Some others have noted that there are theories where energy and/or matter are spontaneously created in empty space. These can coexist with the heat death fate if the new energy is also evenly spread, which it probably would be in such a uniformly boring heat-dead universe. Still no way to create a new free energy gradient.

I find this an interesting fate because it's also reflected in some religions and philosophies, where everything becomes one at the end of time.