This Hubble picture was just released this morning. Enjoy it while it lasts. In the future those lovely spirals will become invisible, according to Lawrence Krauss’ new book “A Universe from Nothing.” I read Krauss’ book as part of my research for yesterday’s column on the origin of the universe, and I learned much more than I could include there.
2 trillion years from now the sun will be toast, but there may still be astronomers on planets orbiting other suns. No matter how advanced telescope technology becomes, it will be physically impossible for anyone to take a picture like the one above. Future astronomers will only see the stars in their own galaxies.
That’s because the expansion of the universe is accelerating, and since space itself is expanding, it doesn’t have to stop at the speed of light. Things will actually move away from us faster than the speed of light, which will make them invisible, as the light they emit will never be able to make progress against the accelerating outward current. Space will stretch the wavelengths of that light into oblivion.
Galaxies will remain intact, since they are bound together by gravity, but as Krauss describes the situation, they will all become isolated island universes.
“Not only will the rest of the universe have disappeared, as my colleague Robert Scherrer of Vanderbilt an I recognized a few years ago, bet essentially all of the evidence that now tell us we live in an expanding universe that began in a Big Bang will also have disappeared.” In which case we live in a fortunate time, and we should enjoy the view.