KNOCKING ON HEAVEN’S DOOR
Physics and Scientific Thinking Illuminate the Universe and the Modern World: By Lisa Randall, Ecco/HarperCollins Publishers.
where is physics headed? Before grappling with this question, it might be wise to ask first where physics is. And the cynical
answer is, about where it was in the 1970s.
That was when the finishing touches were put on the so-called
Standard Model of particle physics. The Standard Model describes, in a single mathematical framework, the basic constituents
of nature and three of the four known forces that govern their interactions: electromagnetism; the “strong” force,
which holds the nucleus of the atom together; and the “weak” force, which causes radioactive decay.
The Standard Model is not particularly elegant; indeed, it’s something of a stick-and-bubble-gum contraption.
But in the decades since it was formulated, it has predicted the result of every experiment in particle physics, and with
is one obvious problem with the Standard Model. It leaves out the fourth force of nature, the earliest one to be discovered
and the one with which we’re most familiar: gravity. Nobody has yet figured out how to describe gravity in the same
language — the language of quantum mechanics — the Standard Model uses to describe the other three forces. So
we need a separate theory for gravity: Einstein’s general relativity theory.
Some physicists of a conservative kidney,
like Freeman Dyson, are reasonably content with this division of labor. Let the Standard Model handle the small stuff (atoms
on down), they say, and general relativity handle the massive stuff (stars on up). Never mind that the two theories give inconsistent
answers at extreme energies, where very small things can also be very massive; we can’t observe such energies anyway.
But other physicists
insist that an entirely new framework must be found, one that would transcend the Standard Model by putting all four forces
on the same theoretical footing. Only then, they argue, will we understand how nature behaves at energies like those that
prevailed at the Big Bang, when the four forces acted as one. The best candidate for such a unifying framework seems to be
theory is a top-down approach to progress in physics — total revolution from above. Once you find the right principles
to describe nature at the very highest energies, all else follows. The problem with string theory is that so far at least,
it makes no testable predictions. Since string theorists are working in the dark, experimentally speaking, some say they are
not really doing science, but rather pure mathematics.
The alternative is a bottom-up approach — gradual
reform from below. And this brings us back to Lisa Randall. She knows as well as her string-theorist colleagues do that the
Standard Model can’t be the whole story. At best, it’s a low-energy approximation of the Truth. But she prefers
to hew closely to the available experimental data, using those data to resolve puzzling features of the Standard Model and
to guess how it might be extended to energies just beyond its ken — the sort of energies that, she hopes, will be attainable
soon in the Large Hadron Collider. …
And here’s where the Large Hadron Collider had better help. At the very least, this
magnificent machine — the biggest ever built, and quite possibly the most picturesque … is expected to blast
into existence the Higgs boson. This is the long-sought missing ingredient of the Standard Model, the one that (if it really
does exist) would be the key to understanding how asymmetries arose between forces that ought to look the same.
Randall strives conscientiously
to explain this Higgs business, as well as the hierarchy problem and her own arrestingly subtle way of dealing with it (which
involves gravity “leaking” through warped dimensions). Such matters, it must be said, are among the very hardest
to get across to non-physicists. If you don’t have the math under your belt, the right metaphors can sometimes give
you the agreeable feeling that you are “almosting it.” … Randall does manage to deliver such moments …
Her philosophical ruminations
are more uneven. She gives a fine analysis of the affinity between scientific and artistic beauty, comparing the broken symmetries
of a Richard Serra sculpture to those at the core of the Standard Model. Elsewhere, though, she is guilty of what might be
called premature intellectual closure.
Can a scientist be religious? Only at the price of inconsistency,
she argues, because scientific determinism is not compatible with belief in a deity who can willfully intervene in the world.
Sympathetic though I am to her conclusion, I would point out that scientific determinism is equally incompatible with free
will and moral responsibility. …
"The ultimate purpose of the work of this God may
never be understood by the [human] mind. Perhaps as it was, as the Baltimore Catechism told me long ago, that God wanted to
be known, loved, and served. If that is true, [God] did so by devising a universe that would make knowledge, love, and service
- Kenneth Miller, Professor of Biology
at Brown University, on why he thinks science and faith are compatible