Yesterday, I
began a discussion on how the universe is
finely-tuned for human existence. We started with an analogy of being lost in a
wood and stumbling onto a life-saving cabin. Then, I noted that just like our
cabin, we see three key areas that are necessary for our shelter to sustain
life. If you haven't read it yet, make sure you do.
Last time we looked
at how the area is just right - that is the laws of the universe allow
life to exist. Today, I'd like to look more closely at the other two features
that make life possible: our solar system is built for life and our planet
itself is just right.
2. Our planet and solar system are poised for life (the cabin is built right)
Going back to our cabin analogy, it's not merely that the area where the
cabin is built is just right for you to survive—the cabin itself has to be made
the right way with the right materials, otherwise it will do you no good at all.
Imagine if the cabin had huge holes in the walls and ceiling. It would let the heat
and the cold in and not sustain your life. Imagine also if the cabin was made out
of paper or sand, which would quickly give way to the wild beasts outside or simple
erosion. None of these situations would be of benefit to you when you needed it
most.
Similar to the cabin, our little neighborhood in the universe, our solar
system and the planet Earth, also show remarkable design for life. In their great
book
Rare Earth, scientists Peter D. Ward and Donald Brownlee note just
how unlikely it is that another planet in the universe would have the perfect conditions
for life that our planet Earth does. We live in a spiral galaxy, but not in a portion
crowded with stars. Our sun sits far enough away from the center of the galaxy,
yet in-between two of its more densely-packed arms, what Ward and Brownlee call
the "Galactic Habitable Zone."
4 They note that the distance of our
Earth from the sun is also perfect , not letting the oceans boil away (possibly
like Venus) or freeze over permanently (like all water on Mars).
5
Our sun is also the right kind
of star. Did you know that 95% of stars in the universe are smaller than our sun?
6 Planets need to be closer to smaller stars in order to get enough warmth for
life, but when planets do get closer, the star's gravity keeps one side of
the planet constantly facing toward it, freezing out the atmosphere. If our sun
were much smaller, it wouldn't put out enough heat, and if it were larger,
it would be so hot that it would sterilize the planet of all life.
7
And because our sun is not too red (which would also make it too cold for
life) or too blue (which would burn too quickly to sustain life), we are able to
exist.
8Everything seems to be not
too hot nor too cold, but just right for life to exist on this particular planet.
Lastly, the fact that we have the gas giant planets (Jupiter, Saturn, Uranus,
and Neptune) at the outside of our solar systems allows life on earth to continue.
According to Ward and Brownlee, these gas giants not only carried elements such
as carbon, nitrogen and water to earth in the early stages of its formation, but
they continue to provide an invaluable service of catching large asteroid-type bodies
that would otherwise smash into earth and extinguish all life on the planet.
9
There are many other examples
of how our solar system is perfectly fit for life, but these will do well for a
start. This is why Ward and Brownlee write, "With the best of intentions,
but limited by natural laws and materials, it is unlikely that Earth could ever
truly be replicated. Too many processes in its formation involved sheer luck."
10 You can see why Paul Davies calls
the Anthropic Principle, "the Goldilocks Principle." Just as Goldilocks
found to porridge and the bed that suited her, we've stumbled onto a cabin
that suits us perfectly.
3. The Earth is stocked for life (the cabin is properly equipped)
We've talked about the area being right for our cabin and the cabin being
built properly to sustain us, but both those things wouldn't do us much good
if we had to ride out several months of winter in a cabin not stocked with all the
things that keep us alive. So it is with the Earth. It's not enough that it
be in the right place with the right laws in the universe; it also has to protect
and provide the ongoing sustenance for any life that may be found here. But yet
again, we find that the Earth is just right to allow mankind to not only live, but
to thrive. For example, the fact that our planet is 70% water has a major impact
on supporting life. If there were too much water, then no dry land would appear
to allow advanced life. Too little water and the temperatures on Earth would vary
too drastically for advanced life to thrive.
Whereas most substances have very
predictable behaviors based on their molecular construction, water seems to be unique
in how it violates these expectations. For example, changing from a liquid to a
solid means that as the molecules of most substances slow down, they get closer
together, making the material heavier in its solid state. However, water does just
the opposite: just before it freezes, it expands, allowing ice to float on liquid
water. If this didn't happen, then all of the Earth's bodies of water
would eventually freeze from the bottom up. But instead of freezing, the ice provides
a cover over the liquid water, helping to retain the liquid water and therefore
also adding to its stabilization of the surface temperature of the Earth.
Beyond
water, other factors make Earth just right for life. The gases that make up our
atmosphere help regulate the Earth's temperature, keeping it even too. Too
many gases and we'd over heat, but too few and life would die from the radiation
penetrating the atmosphere from space.
11
Astronomer Hugh Ross gives us an impressive list of dozens of such conditions
for life to thrive on earth: If the oxygen-to-nitrogen ratio in our atmosphere were
larger, advanced life functions would proceed too quickly; if it were smaller, advanced
life functions would proceed too slowly. If the Earth's crust were thicker,
too much oxygen would be transferred from the atmosphere to the crust; but if thinner,
volcanic and tectonic activity would be too great. Water vapor levels in the atmosphere
are just right; if greater, a runaway greenhouse effect would develop; but if less,
rainfall would be too meager for advanced life on the land.
12
The fact that our Earth has
a single, sizable moon also becomes crucial to our existence on the planet. In their
book
The Privileged Planet, Guillermo Gonzalez and Jay Richards write that
the Moon serves to stabilize our planet's rotation, keeps the Earth's
axis at the perfect tilt to allow consistent seasons, and — by raising the ocean's
tides — it delivers nutrients stirred up from the ocean floor and delivers them
on land while it simultaneously promotes ocean currents distributing heated water
throughout the different oceans.
13
Is it All Just a Coincidence?
Perhaps
someone desperate might hope to find a cabin in the wood, but to find it filled
with the presence of your favorite food, stocked with insulin in the medicine cabinet,
and containing all the clothing in your size is far beyond a stroke of luck, especially
since these things are not contingent on each other. In finding so many of these "coincidences,"
it would be irrational to draw a conclusion that this was all chance. You may not
be able to explain why it all works out, but it's obvious that whoever built
this cabin had you in mind and did it on purpose. And scientists are finding more
and more that the sheer number of "coincidences" in the universe of
physical laws being just right for life is simply too much to dismiss. Paul Davies
goes on to say:
"Certainly the existence of life as we know it… would
be threatened by just the tiniest change in the strengths of the fundamental forces,
for example. The laws that characterize our actual universe, as opposed to an infinite
number of alternative possible universes, seem almost contrived — fine-tuned some
commentators have claimed — so that life and consciousness may emerge. To quote
Dyson again: it is almost as if 'the universe knew we were coming'."14
Indeed, the mountain of such factors points to the fact that someone "rigged"
the system. Perhaps some of these factors are found elsewhere in the universe —
there are other spiral galaxies and yellow suns, though not plentiful, that do exist.
However, I think that when taken together, this evidence implies much more than
mere coincidences. Robin Collins quotes philosopher John Leslie correctly saying, "Clues
heaped upon clues can constitute weighty evidence, despite doubts about each element
in the pile."
15 If the universe
itself is put together correctly to support life, then we can't stop at the
universe as an explanation for our existence. We have to go to something or Someone
who existed before the universe, Who designed the universe with the purpose of creating
it so humanity can live and thrive in it. The design of the universe argues for
the existence of God.
References
