THE NEW YORK TIMES December 18, 2007
Laws of Nature, Source Unknown
By DENNIS OVERBYE
“Gravity,” goes the slogan on posters and bumper stickers. “It isn’t just
a good idea. It’s the law.”
And what a law. Unlike, say, traffic or drug laws, you don’t have a
choice about obeying gravity or any of the other laws of physics. Jump and
you will come back down. Faith or good intentions have nothing to do with
Existence didn’t have to be that way, as Einstein reminded us when he
said, “The most incomprehensible thing about the universe is that it is
comprehensible.” Against all the odds, we can send e-mail to Sri Lanka,
thread spacecraft through the rings of Saturn, take a pill to chase the inky
tendrils of depression, bake a turkey or a soufflé and bury a jump shot from
Yes, it’s a lawful universe. But what kind of laws are these, anyway,
that might be inscribed on a T-shirt but apparently not on any stone tablet
that we have ever been able to find?
Are they merely fancy bookkeeping, a way of organizing facts about the
world? Do they govern nature or just describe it? And does it matter that we
don’t know and that most scientists don’t seem to know or care where they
Apparently it does matter, judging from the reaction to a recent article
by Paul Davies, a cosmologist at Arizona State University and author of
popular science books, on the Op-Ed page of The New York Times.
Dr. Davies asserted in the article that science, not unlike religion,
rested on faith, not in God but in the idea of an orderly universe. Without
that presumption a scientist could not function. His argument provoked an
avalanche of blog commentary, articles on Edge.org and letters to The Times,
pointing out that the order we perceive in nature has been explored and
tested for more than 2,000 years by observation and experimentation. That
order is precisely the hypothesis that the scientific enterprise is engaged
David J. Gross, director of the Kavli Institute for Theoretical Physics
in Santa Barbara, Calif., and co-winner of the Nobel Prize in physics, told
me in an e-mail message, “I have more confidence in the methods of science,
based on the amazing record of science and its ability over the centuries to
answer unanswerable questions, than I do in the methods of faith (what are
Reached by e-mail, Dr. Davies acknowledged that his mailbox was
“overflowing with vitriol,” but said he had been misunderstood. What he had
wanted to challenge, he said, was not the existence of laws, but the
conventional thinking about their source.
There is in fact a kind of chicken-and-egg problem with the universe and
its laws. Which “came” first — the laws or the universe?
If the laws of physics are to have any sticking power at all, to be real
laws, one could argue, they have to be good anywhere and at any time,
including the Big Bang, the putative Creation. Which gives them a kind of
transcendent status outside of space and time.
On the other hand, many thinkers — all the way back to Augustine —
suspect that space and time, being attributes of this existence, came into
being along with the universe — in the Big Bang, in modern vernacular. So
why not the laws themselves?
Dr. Davies complains that the traditional view of transcendent laws is
just 17th-century monotheism without God. “Then God got killed off and the
laws just free-floated in a conceptual vacuum but retained their theological
properties,” he said in his e-mail message.
But the idea of rationality in the cosmos has long existed without
monotheism. As far back as the fifth century B.C. the Greek mathematician
and philosopher Pythagoras and his followers proclaimed that nature was
numbers. Plato envisioned a higher realm of ideal forms, of perfect chairs,
circles or galaxies, of which the phenomena of the sensible world were just
flawed reflections. Plato set a transcendent tone that has been popular,
especially with mathematicians and theoretical physicists, ever since.
Steven Weinberg, a Nobel laureate from the University of Texas, Austin,
described himself in an e-mail message as “pretty Platonist,” saying he
thinks the laws of nature are as real as “the rocks in the field.” The laws
seem to persist, he wrote, “whatever the circumstance of how I look at them,
and they are things about which it is possible to be wrong, as when I stub
my toe on a rock I had not noticed.”
The ultimate Platonist these days is Max Tegmark, a cosmologist at the
Massachusetts Institute of Technology. In talks and papers recently he has
speculated that mathematics does not describe the universe — it is the
Dr. Tegmark maintains that we are part of a mathematical structure,
albeit one gorgeously more complicated than a hexagon, a multiplication
table or even the multidimensional symmetries that describe modern particle
physics. Other mathematical structures, he predicts, exist as their own
universes in a sort of cosmic Pythagorean democracy, although not all of
them would necessarily prove to be as rich as our own.
“Everything in our world is purely mathematical — including you,” he
wrote in New Scientist.
This would explain why math works so well in describing the cosmos. It
also suggests an answer to the question that Stephen Hawking, the English
cosmologist, asked in his book, “A Brief History of Time”: “What is it that
breathes fire into the equations and makes a universe for them to describe?”
Mathematics itself is on fire.
Not every physicist pledges allegiance to Plato. Pressed, these
scientists will describe the laws more pragmatically as a kind of shorthand
for nature’s regularity. Sean Carroll, a cosmologist at the California
Institute of Technology, put it this way: “A law of physics is a pattern
that nature obeys without exception.”
Plato and the whole idea of an independent reality, moreover, took a shot
to the mouth in the 1920s with the advent of quantum mechanics. According to
that weird theory, which, among other things, explains why our computers
turn on every morning, there is an irreducible randomness at the microscopic
heart of reality that leaves an elementary particle, an electron, say, in a
sort of fog of being everywhere or anywhere, or being a wave or a particle,
until some measurement fixes it in place.
In that case, according to the standard interpretation of the subject,
physics is not about the world at all, but about only the outcomes of
experiments, of our clumsy interactions with that world. But 75 years later,
those are still fighting words. Einstein grumbled about God not playing
Steven Weinstein, a philosopher of science at the University of Waterloo,
in Ontario, termed the phrase “law of nature” as “a kind of honorific”
bestowed on principles that seem suitably general, useful and deep. How
general and deep the laws really are, he said, is partly up to nature and
partly up to us, since we are the ones who have to use them.
But perhaps, as Dr. Davies complains, Plato is really dead and there are
no timeless laws or truths. A handful of poet-physicists harkening for more
contingent nonabsolutist laws not engraved in stone have tried to come up
with prescriptions for what John Wheeler, a physicist from Princeton and the
University of Texas in Austin, called “law without law.”
As one example, Lee Smolin, a physicist at the Perimeter Institute for
Theoretical Physics, has invented a theory in which the laws of nature
change with time. It envisions universes nested like Russian dolls inside
black holes, which are spawned with slightly different characteristics each
time around. But his theory lacks a meta law that would prescribe how and
why the laws change from generation to generation.
Holger Bech Nielsen, a Danish physicist at the Niels Bohr Institute in
Copenhagen, and one of the early pioneers of string theory, has for a long
time pursued a project he calls Random Dynamics, which tries to show how the
laws of physics could evolve naturally from a more general notion he calls
On his Web site, Random Dynamics, he writes, “The ambition of Random
Dynamics is to ‘derive’ all the known physical laws as an almost unavoidable
consequence of a random fundamental ‘world machinery.’”
Dr. Wheeler has suggested that the laws of nature could emerge
“higgledy-piggledy” from primordial chaos, perhaps as a result of quantum
uncertainty. It’s a notion known as “it from bit.” Following that logic,
some physicists have suggested we should be looking not so much for the
ultimate law as for the ultimate program..
Anton Zeilinger, a physicist and quantum trickster at the University of
Vienna, and a fan of Dr. Wheeler’s idea, has speculated that reality is
ultimately composed of information. He said recently that he suspected the
universe was fundamentally unpredictable.
I love this idea of intrinsic randomness much for the same reason that I
love the idea of natural selection in biology, because it and only it
ensures that every possibility will be tried, every circumstance tested,
every niche inhabited, every escape hatch explored. It’s a prescription for
novelty, and what more could you ask for if you want to hatch a fecund
But too much fecundity can be a problem. Einstein hoped that the universe
was unique: given a few deep principles, there would be only one consistent
theory. So far Einstein’s dream has not been fulfilled.Cosmologists and
physicists have recently found themselves confronted by the idea of the
multiverse, with zillions of universes, each with different laws, occupying
a vast realm known in the trade as the landscape.
In this case there is meta law — one law or equation, perhaps printable
on a T-shirt — to rule them all. This prospective lord of the laws would be
string theory, the alleged theory of everything, which apparently has 10500
solutions. Call it Einstein’s nightmare.
But it is soon for any Einsteinian to throw in his or her hand. Since
cosmologists don’t know how the universe came into being, or even have a
convincing theory, they have no way of addressing the conundrum of where the
laws of nature come from or whether those laws are unique and inevitable or
flaky as a leaf in the wind.
These kinds of speculation are fun, but they are not science, yet.
“Philosophy of science is about as useful to scientists as ornithology is to
birds,” goes the saying attributed to Richard Feynman, the late Caltech
Nobelist, and repeated by Dr. Weinberg.
Maybe both alternatives — Plato’s eternal stone tablet and Dr. Wheeler’s
higgledy-piggledy process — will somehow turn out to be true. The dichotomy
between forever and emergent might turn out to be as false eventually as the
dichotomy between waves and particles as a description of light. Who knows?
The law of no law, of course, is still a law.
When I was young and still had all my brain cells I was a bridge fan, and
one hand I once read about in the newspaper bridge column has stuck with me
as a good metaphor for the plight of the scientist, or of the citizen
cosmologist. The winning bidder had overbid his hand. When the dummy cards
were laid, he realized that his only chance of making his contract was if
his opponents’ cards were distributed just so.
He could have played defensively, to minimize his losses. Instead he
played as if the cards were where they had to be. And he won.
We don’t know, and might never know, if science has overbid its hand.
When in doubt, confronted with the complexities of the world, scientists
have no choice but to play their cards as if they can win, as if the
universe is indeed comprehensible. That is what they have been doing for
more than 2,000 years, and they are still winning.
Correction: December 19, 2007
An article in Science Times on Tuesday about the laws of physics and
nature misstated the time in which Plato was forming his idea of a higher
realm of ideal forms. It was in the fourth century B.C.; it was not “a few
hundred years” after the fifth century B.C., when the Greek mathematician
and philosopher Pythagoras and his followers proclaimed that nature was