Designed for Discovery
by Guillermo Gonzalez and Jay W. Richards
Read any book on the history of scientific discovery, and you'll find
magnificent tales of human ingenuity, persistence, and dumb luck. What you
probably won't see is any discussion of the conditions necessary for such
feats. A discovery requires a person to do the discovering, and a set of
circumstances that makes it possible. Without both, nothing gets
Although scientists don't often discuss it, the degree to which we can
"measure" the wider universe from our Earthly home-and not just our immediate
surroundings-is surprising. Few have considered what science would have
been like in, say, a different planetary environment. Still fewer have realized
that pursuing that question systematically leads to unanticipated evidence for
Think of the following features of our Earthly home: the transparency of
Earth's atmosphere in the visual region of the spectrum, shifting crustal
plates, a large Moon, and our particular location in the Milky Way Galaxy.
Without each of these assets, we would have a very hard time learning about the
universe. It is not idle speculation to ask how our view of the universe would
be impaired if, for example, our home world were perpetually covered by thick
clouds. After all, our Solar System contains several examples of such worlds.
Just think of Venus, Jupiter, Saturn, and Saturn's moon, Titan. These would be
crummy places to do astronomy.
We can make similar comparisons at the galactic level. If we were closer to
our galaxy's center or one of its major, and dustier, spiral arms, for
instance-the extra dust would impede our view of the distant universe. In fact,
we probably would have missed one of the greatest discoveries in the history of
astronomy: the faint cosmic microwave background radiation. That discovery was
the linchpin in deciding between the two main cosmological theories of the
twentieth century. Underlying this debate was one of the most fundamental
questions we can ask about the universe: Is it eternal, or did it have a
The Steady State theory posited an eternal universe, while the Big Bang
theory implied a beginning. For a few decades, there was no direct evidence to
decide between the two. But Big Bang theory predicted a remnant radiation left
over from the earlier, hotter and denser period of cosmic history. Steady State
theory made no such prediction. As a result, when scientists discovered the
cosmic background radiation in 1965, it was the death knell for Steady State.
But that discovery could not have been made just anywhere. Our special vantage
point in the Milky Way Galaxy allowed us to choose between these two profoundly
different views of origins.
In The Privileged Planet: How Our Place in the Cosmos is Designed for
Discovery we discuss these and many comparable examples to show that we
inhabit a planet privileged for scientific observation and discovery. But
there's more to the story. Not only is the Earth a privileged place for
discovery, it is also a privileged place for life. It is the connection between
life and discovery that we think suggests purpose and not mere chance.
Physicists and cosmologists began realizing decades ago that the values of
the constants of physics-features of the universe that are the same
everywhere-must be very close to their actual values for life to be possible.
As a result, they began talking about the universe being "fine tuned" for life.
And some have even begun to suggest that fine tuning implies a fine tuner. Much
more recently, astrobiologists began learning that even in our fine tuned
universe, many other "local" things must go just right to get a habitable
If you were a cosmic chef, your recipe for cooking up a habitable planet
would have many ingredients. You would need a rocky planet large enough to hold
on to a substantial atmosphere and oceans of water and to retain internal heat
for billions of years. You would need the right kind of atmosphere. You would
need a large moon to stabilize the tilt of planet's rotation on its axis. You
would need the planet to have a nearly circular orbit around a main sequence
star similar to our sun. You would need to give that planet the right kind of
planetary neighbors within its star system. And you would need to put that
system far from the center, edges and spiral arms of a galaxy like the Milky
Way. You would need to cook it during a narrow window of time in the history of
the universe. And so on. This is a partial list, but you get the idea.
This evidence is becoming well known among scientists interested in the
question of life in the universe. Researchers involved in the search for
extraterrestrial intelligence (SETI), for instance, are especially interested
in knowing what life needs. That knowledge would allow them to determine their
chances of finding another communicating civilization. Unfortunately for SETI
researchers, the probabilities are not looking promising. Recent evidence
favors the so-called Rare Earth hypothesis (named after a book written by
Donald Brownlee and Peter Ward in 2000). The theory posits that planets hosting
simple life may be common, but planets with complex life are very rare.
We do not yet know if we are alone in the universe. The universe is a big
place with vast resources. Astrobiology research has not yet matured to the
point where we can assign precise probabilities to all the factors needed to
make a planet habitable. We cannot yet state with certainty whether they
exhaust all the available resources. Perhaps the universe is big enough that at
least one habitable planet would have emerged by chance. Or perhaps not. In the
meantime, it's difficult to make a strong case for intelligent design based
merely on the conclusion that habitable planets are rare.
That said, we do think there is evidence for design in the neighborhood.
For, as we argue in The Privileged Planet, there is a suspicious
pattern between the needs of life and the needs of science. The same narrow
conditions that make a planet habitable for complex life, also make it the best
place overall for making a wide range of scientific discoveries. In other
words, if we compare our local environment with other, less hospitable
environments, we find a striking coincidence: Observers find themselves in the
best places overall for observing. For instance, the atmosphere that complex
life needs is also an atmosphere that is transparent to the most scientifically
useful "light." The geology and planetary system that life needs is also the
best, overall, for allowing that life to reconstruct events from the past. And
the most habitable region of the galaxy, and the most habitable time in cosmic
history, are also the best place and time, overall, for doing astronomy and
cosmology. If the universe is merely a blind concatenation of atoms colliding
with atoms, and nothing else, you wouldn't expect this pattern. You would
expect it, on the other hand, if the universe is designed for discovery.