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     The New York Times, October 8, 2006

     Oh, for the Simple Days of the Big Bang
     By GEORGE JOHNSON

     FOURTEEN years ago, when a Berkeley astronomer named
     George F. Smoot declared that he and his satellite, the
     Cosmic Background Explorer, or COBE, had detected the
     astrophysical equivalent of the fingerprints of God, his
     euphoria was easy to understand. For a few happy years,
     one of the last big pieces of the cosmological puzzle
     seemed to be in place - an explanation why the universe
     has blossomed into such an interesting place to live.

     Had it not been for the whorls and dimples Dr. Smoot and
     his NASA collaborator, John C. Mather, found in the
     background radiation - the afterimage of the Big Bang -
     there would be no cosmic scenery. No galaxies or other
     vast conglomerations of matter, just a smooth expanse of
     visual nothing. Kansas instead of Colorado.

     Subsequent discoveries have muddled the picture, so much
     so that last week's announcement that the two men will
     share a Nobel Prize in physics was almost bittersweet -
     an occasion to celebrate a pivotal moment in science but
     also to look back with nostalgia on more innocent times.

     The creation story supported by the data from the COBE
     satellite had seemed almost tantalizingly complete. Dr.
     Smoot's smudges themselves weren't sticky enough to
     gather particles into globs the size of the Milky Way or
     the Virgo supercluster. But if you spiked the Big Bang
     with an invisible additive called dark matter - a
     clumping factor - and hot-rodded the theory with a brief,
     early burst of rapid expansion called cosmological
     inflation, you could get the tiny irregularities in the
     background radiation to sprawl into something like
     today's sky.

     If only it had been that simple. Six years after COBE,
     another Berkeley scientist, Saul Perlmutter, found
     something that almost no one had expected. By now, it was
     assumed, the universe should have settled down, expanding
     at a steady pace or even slowing, braked by its own
     gravity. Instead it appeared to be in overdrive, not
     ballooning as violently as it had in the inflationary era
     but expanding at a faster and faster rate. Something
     seemed to be pushing on the accelerator - what has come
     to be called dark energy, a mysterious kind of
     anti-gravity.

     Shoehorning the new ingredient into the prevailing
     framework has created new Nobel-sized problems. Basic
     physics predicts that if it exists at all, this repulsive
     force should be extremely large. Instead, the dark energy
     is infinitesimal and no one has been able to say why.

     Except, that is, for followers of a controversial
     doctrine called the anthropic principle. There is no
     fundamental reason, they say, why the dark energy is so
     weak. It is just that if it were much stronger, space
     would have expanded too rapidly to harbor stars and,
     ultimately, life. The implication is that there is a
     multitude of possible universes, each with its own
     physics. Naturally, we are in one where it is possible
     for us to exist.

     Depending on their temperament, physicists find the idea
     of a spectrum of universes each ruled by different laws
     either liberating or a source of despair. Since the days
     of the Greek philosophers, the reigning assumption, more
     mystical than scientific, has been that things are
     necessarily the way they are. There is one universe and
     lurking somewhere within is a deep principle that
     explains why the strength of gravity, the speed of light,
     the heft of matter - all the constants of nature - have
     taken certain values.

     With Smoot and Mather, science seemed closer to finding
     the key - a hope that now sometimes seems as egotistical
     as the pre-Copernican belief that we live at the center
     of creation instead of on a hospitable rock orbiting an
     obscure star in an obscure galaxy in a universe that may
     be obscurer still.

     More recently this faith in our own uniqueness has been
     tested again by a related finding in superstring theory,
     which began some 30 years ago as an attempt to pull all
     the numbers of the cosmos from a few basic calculations.
     Just as x + y + z = 42 has many solutions (infinitely many
     if you allow fractions or negative numbers), so do the
     equations of superstring theory. By one reckoning, the
     number of conceivable universes, each with a different
     dose of dark energy, is so vast that it is "measured not
     in the millions or billions but in googols or
     googolplexes." (Before it was retooled into the name of a
     search engine, a googol was defined as 10 to the power of
     100 and a googolplex as 10 to the power of googol.)

     Why we find ourselves in, say, universe number
     110,310,077,252 would again be a tautology: if we weren't
     we wouldn't be here to ask. There may yet be a way out of
     the muddle with some insight that focuses superstrings
     into a beam illuminating the one true theory.

     But new ideas, some physicists complain, are a dime a
     dozen. What they crave is new data, perhaps from the
     Large Hadron Collider scheduled to go online near Geneva
     next year. What is discovered there might do for physics
     what the COBE measurements did for cosmology in 1992:
     provide some long-needed reality testing.

     If not there is always Plan B. Maybe physicists in another
     universe are coming closer to an answer.