Empty universe: Cosmology in the year 100 billion

April 5, 2011 | Source: New Scientist Space

Only a single island of stars remains, floating in an unutterably vast, unutterably empty ocean of space. This is a vision of the Milky Way when the cosmos is 10 times older than it is today.The perpetrator of this desperately lonely future is dark energy.

Freeman Dyson speculates whether such a future could be changed by the intervention of intelligent life. He wonders whether a super civilisation might actually be able to move galaxies about by harnessing their gravitational energy. By concentrating them in one giant super-cluster, the inhabitants of these galaxies will at least be able to huddle together as other galaxies disappear over the horizon. “Our descendants would stay in communication with 100 million galaxies instead of only one,” says Dyson.

Loeb points out, drolly, that moving galaxies will be very hard indeed. It would be far simpler, he maintains, to identify a large concentration of galaxies, such as the Coma cluster, and go there, although the 320 million-light year journey would be a very long one. “Travelling is a lot easier than cosmic engineering,” he says.