HOW must the glorious spectacle of the stars appear
to gloomy people? Surely as a most miserable sight. Because while most
of us love the wonder and beauty of the cosmos, they will only see its
waste of energy.
``Look at all that hydrogen burning away,'' they will
say. ``What will replace it? Certainly, new stars will be formed, and
new ones after that. But this process cannot last for ever. The day will
come when there will be no more hydrogen. Even now, the universe is
dying! If only there was some way to reverse its decay!''
One of the most memorable works of science fiction is
Isaac Asimov's 1956 short story ``The Last Question.'' It traces
trillions of years of future history in which people?and the successors
of people—ask their most advanced computers the same repeated
question: ``Can entropy be reversed?'' And always, until the end, the
same answer comes back: ``Insufficient Data for Meaningful Answer.'' In
one poignant passage, an interstellar pioneer explains the problem to
his child:
``What's entropy, Daddy?'' shrilled Jerrodette.
``Entropy, little sweet, is just a word which means
the amount of running down of the universe. Everything runs down, you
know, like your little walkie-talkie robot, remember?''
``Can't you just put in a new power-unit, like with
my robot?''
``The stars are the power-units, dear. Once
they're gone, there are no more power-units.''
Jerodette at once set up a howl. ``Don't let them,
Daddy. Don't let the stars run down.''
At last, thousands of trillions of years later, when
the universe is black and empty of stars, the last living entity
descended from man asks the last computer evolved from all the computers
that ever were asks: ``Can entropy be reversed?''
This time, after brooding for almost an age over all
the data that these computers have ever accumulated, the machine
answers: ``Let there be light!'' And light returns.
Back in 1956, it must have seemed difficult to
imagine what data the computer could have acquired that would enable it
to reverse entropy and thus violate the second law of thermodynamics,
one of the most fundamental laws of nature.
But today, we can see how perhaps it might be done:
if you want to disobey a law of nature, then do it somewhere where
nature's laws do not apply. In other words, create a new universe!
This should not be an insuperable problem. As Fred
Adams and Greg Laughlin explain in their 1999 book The Five
Ages of the Universe: Inside the Physics of Eternity, an infinite
number of universes is likely to exist, ours being only one of them.
To make another, one need only to create a condition
of extreme gravitational collapse, and fundamental particles will burst
out ``somewhen else'', coalescing, in time, into countless hydrogen
atoms in a region of space that will inflate into a volume billions of
light-years across. These atoms will in turn form galaxies and stars.
The creators will never know what kind of universe
they have created, for they cannot be part of it. They will know only
that they have averted the tragedy of eternal night.
