SCIENCE, we are repeatedly told, is the most reliable form of knowledge about the world
because it is based on testable hypotheses. Religion, by contrast, is based on
faith. The term “doubting Thomas” well illustrates the difference. In science,
a healthy skepticism is a professional necessity, whereas in religion, having
belief without evidence is regarded as a virtue.
The
problem with this neat separation into “non-overlapping magisteria,” as Stephen
Jay Gould described science and religion, is that science has its own
faith-based belief system. All science proceeds on the assumption that nature
is ordered in a rational and intelligible way. You couldn’t be a scientist if
you thought the universe was a meaningless jumble of odds and ends haphazardly
juxtaposed. When physicists probe to a deeper level of subatomic structure, or
astronomers extend the reach of their instruments, they expect to encounter
additional elegant mathematical order. And so far this faith has been
justified.
The
most refined expression of the rational intelligibility of the cosmos is found
in the laws of physics, the fundamental rules on which nature runs. The laws of
gravitation and electromagnetism, the laws that regulate the world within the
atom, the laws of motion — all are expressed as tidy mathematical
relationships. But where do these laws come from? And why do they have the form
that they do?
When
I was a student, the laws of physics were regarded as completely off limits.
The job of the scientist, we were told, is to discover the laws and apply them,
not inquire into their provenance. The laws were treated as “given” — imprinted
on the universe like a maker’s mark at the moment of cosmic birth — and fixed
forevermore. Therefore, to be a scientist, you had to have faith that the
universe is governed by dependable, immutable, absolute, universal,
mathematical laws of an unspecified origin. You’ve got to believe that these
laws won’t fail, that we won’t wake up tomorrow to find heat flowing from cold
to hot, or the speed of light changing by the hour.
Over
the years I have often asked my physicist colleagues why the laws of physics
are what they are. The answers vary from “that’s not a scientific question” to
“nobody knows.” The favorite reply is, “There is no reason they are what they
are — they just are.” The idea that the laws exist reasonlessly is deeply
anti-rational. After all, the very essence of a scientific explanation of some
phenomenon is that the world is ordered logically and that there are reasons
things are as they are. If one traces these reasons all the way down to the
bedrock of reality — the laws of physics — only to find that reason then
deserts us, it makes a mockery of science.
Can
the mighty edifice of physical order we perceive in the world about us
ultimately be rooted in reasonless absurdity? If so, then nature is a
fiendishly clever bit of trickery: meaninglessness and absurdity somehow masquerading
as ingenious order and rationality.
Although
scientists have long had an inclination to shrug aside such questions
concerning the source of the laws of physics, the mood has now shifted
considerably. Part of the reason is the growing acceptance that the emergence
of life in the universe, and hence the existence of observers like ourselves,
depends rather sensitively on the form of the laws. If the laws of physics were
just any old ragbag of rules, life would almost certainly not exist.
A
second reason that the laws of physics have now been brought within the scope
of scientific inquiry is the realization that what we long regarded as absolute
and universal laws might not be truly fundamental at all, but more like local
bylaws. They could vary from place to place on a mega-cosmic scale. A God’s-eye
view might reveal a vast patchwork quilt of universes, each with its own
distinctive set of bylaws. In this “multiverse,” life will arise only in those
patches with bio-friendly bylaws, so it is no surprise that we find ourselves
in a Goldilocks universe — one that is just right for life. We have selected it
by our very existence.
The
multiverse theory is increasingly popular, but it doesn’t so much explain the
laws of physics as dodge the whole issue. There has to be a
physical mechanism to make all those universes and bestow bylaws on them. This
process will require its own laws, or meta-laws. Where do they come from? The
problem has simply been shifted up a level from the laws of the universe to the
meta-laws of the multiverse.
Clearly, then, both religion and science are founded on
faith — namely, on belief in the existence of something outside the universe,
like an unexplained God or an unexplained set of physical laws, maybe even a
huge ensemble of unseen universes, too. For that reason, both
monotheistic religion and orthodox science fail to provide a complete account
of physical existence.
This
shared failing is no surprise, because the very notion of physical law is a
theological one in the first place, a fact that makes many scientists squirm.
Isaac Newton first got the idea of absolute, universal, perfect, immutable laws
from the Christian doctrine that God created the world and ordered it in a
rational way. Christians envisage God as upholding the natural order from
beyond the universe, while physicists think of their laws as inhabiting an
abstract transcendent realm of perfect mathematical relationships.
And
just as Christians claim that the world depends utterly on God for its
existence, while the converse is not the case, so physicists declare a
similar asymmetry: the universe is governed by eternal laws (or meta-laws), but
the laws are completely impervious to what happens in the universe.
It
seems to me there is no hope of ever explaining why the physical universe is as
it is so long as we are fixated on immutable laws or meta-laws that exist
reasonlessly or are imposed by divine providence. The alternative is to regard
the laws of physics and the universe they govern as part and parcel of a unitary
system, and to be incorporated together within a common explanatory
scheme.
In
other words, the laws should have an explanation from within the universe and
not involve appealing to an external agency. The specifics of that explanation
are a matter for future research. But until science comes up with a testable
theory of the laws of the universe, its claim to be free of faith is manifestly
bogus.
Paul Davies is the director of Beyond, a research center at Arizona
State University, and the author of “Cosmic Jackpot: Why Our Universe Is Just
Right for Life.”