In yesterday’s NY Times, Dennis Overbye comments on what he considers “one of the more depressing scientific papers” he has ever read:
If things keep going the way they are, Lawrence Krauss of Case Western Reserve University and Robert J. Scherrer of Vanderbilt University calculate, in 100 billion years the only galaxies left visible in the sky will be the half-dozen or so bound together gravitationally into what is known as the Local Group, which is not expanding and in fact will probably merge into one starry ball.
Unable to see any galaxies flying away, those astronomers will not know the universe is expanding and will think instead that they are back in the static island universe of Einstein. As the authors, who are physicists, write in a paper to be published in The Journal of Relativity and Gravitation, â€œobservers in our â€˜island universeâ€™ will be fundamentally incapable of determining the true nature of the universe.â€
That the universe would become increasingly cold and lightless was suggested in 1987 by mathematician George Ellis, who wrote that even ordinary expansion “would gradually carry most galaxies too far away to be seen, setting the stage for cosmic ignorance.”
In my youth it was still thought possible that the universe might collapse back onto itself. Remember those searches for missing mass in the hope that there would be enough to pull everything back, enough for another big bang, another rebirth of the universe, another chance for Shakespeare to explore Hamlet’s motives? Alas, the dastardly data, like discovering one’s parents playing Santa Claus late on Christmas Eve, have disproved the possibility.
Worse, the existence of dark energy accelerates the expansion process, meaning that this bleak future will happen sooner, though we won’t be here on earth wondering why there are fewer galaxies in the sky than grains of sand on the beach inasmuch as the earth will be consumed by the sun in a mere 5 billion years.
But might we be somewhere?