This post concludes my series on the 2022 Dallas Conference on Science and Faith, and the final speaker was Dr. Casey Luskin, who holds a Ph.D. in geology. His topic was titled, The Good Earth: Insights from geology on the design of our planet for life.
While Christians certainly believe God created everything, Luskin argues that there is something special about earth, especially when compared to every other planet we know. Earth seems to be designed with life in mind.
Luskin pointed out something all scientists can agree on: at one time, earth was inhabitable. But from there, what scientists believe varies according to their worldview. For Christians, Genesis 1:2 tells us that the earth was formless and empty, covered in water. Then God went to work designing the earth, transforming it into a habitable planet to support life. And if we examine the way our universe works, we can identify elements of design, which is exactly what we’d expect if God exists. Further, by studying geology, we can learn what is required to terraform a planet and make it habitable for life.
To start with, the earth’s magnetic field is vital for life. It acts like a deflector shield, protecting our atmosphere from being stripped away by the solar wind. Without a strong magnetic field, life wouldn’t exist.
Sure, other planets have a magnetic fields too, like Mercury, which has a very weak magnetic field, and Venus and Mars, whose magnetic fields are almost non-measurable. And then there are the gas giants, which contain very strong magnetic fields, like Jupiter, Saturn, Neptune and Uranus. But despite their strong fields, they can’t sustain life… they have no surface, they contain too much heat, the pressure is too great, and there’s atmospheric turbulence. Earth is the only rocky, terrestrial planet with a strong magnetic field, making it unique.
Surprisingly, another factor making earth habitable is plate tectonics. I didn’t realize this, but without plate tectonics, the oceans would be depleted of much needed nutrients. For instance, says Luskin, organisms living in the oceans require many elements (carbon, calcium, sulfur, etc.) to survive. As it turns out, dead organisms constantly sink to the bottom and are deposited in the sediment and “locked up”. If this were to go on indefinitely, the nutrients necessary for life would be gone.
Fortunately, Luskin explains, plate tectonics solves this problem by recycling the remains buried within the sea floor by the upwelling of magma and gases. This creates a cycle in which these elements may return to the ocean over and over again.
The book, Rare Earth, summarizes this nicely: “It may be that plate tectonics is the central requirement for life on a planet and that it is necessary for keeping the world supplied with water.” No other planet in our solar system has plate tectonics, making earth special, and I find that significant.
The next ingredient for life is water, and it must be in liquid form. But in order for a planet to have enough liquid water to sustain life, there must be a mechanism to capture it and form oceans. Further, the water in the center of the planet must be able to make its way to the surface, while none of it is lost to space.
Scientists admit they don’t have a good explanation as to why earth has so much water. Many, in fact, claim we shouldn’t expect to have any water at all. Luskin quotes from the book, How to Build a Habitable Planet, which says, “Based on the observation that the earth is depleted in potassium and other moderately volatile elements, our planet would not be expected to have any water. Somehow earth got just about an ideal amount of water to support life.” Exactly.
Luskin considers a number of secular models and hypothesis, including the Nebular Hypothesis, the concept of the ‘frost’ or ‘snow’ line, and cometary delivery. None of these can account for the amount of water we have on earth. Yet earth just happens to be in the perfect spot to have liquid water on its surface. The Temperature isn’t too hot to be vaporized, or too cold to freeze.
Next, once a planet has water, it can’t lose it over time. Thus, the earth was designed to retain its water with an electric field that’s just right… air pressure that’s just right… and temperature that’s just right.
Having an atmosphere is vital to life, and the earth’s atmosphere is perfect. It keeps the air pressure light enough for evaporation, yet strong enough to repel asteroids. The composition of the atmosphere is perfect, keeping elements like oxygen and nitrogen balanced. If there were too little oxygen, respiration wouldn’t be possible, and if there were too much, the atmosphere would explode.
Helping maintain the atmosphere is gravity. Earth’s gravity is strong enough to hold important gases, but not too strong, or volatile gases would ignite, which would be very bad.
It can rightly be said that the earth has a global thermostat, keeping the temperature just right.
Interestingly, the visible light spectrum has to be just right, otherwise photosynthesis could not happen. The earth’s atmosphere was designed to allow the perfect amount of visible light to pass through.
Luskin observes that earth appears uniquely designed for life. And I would argue that’s not a coincidence.
Atheists must claim all this happened by accident, and there’s nothing intentional about it. But the idea that a planet not only has all the perfect ingredients to sustain life, but that complex life spontaneously appeared, is nothing short of miraculous. The fact that conditions on earth are perfect for life should invoke some level of skepticism toward secular theories. Can blind chance actually have any explanatory power over such a complex system? No, not according to practical science.
A better explanation is that God really does exist, and he’s the one who designed earth to support life. The Bible provides the perfect explanation. Simple, yet elegant.