Saturday, August 22, 2020

Eccentric Orbits and the Glory of God

 

It turns out that two sentences, one from a recent scientific paper and one from an ancient biblical prophet, are related to each other. Here are the two sentences:

Solar System orbital eccentricities are unusually low compared with those of exoplanets. (from Exoplanet orbital eccentricity, Multiplicity relations and the Solar system by Mary Anne Limbach and Edwin L. Turner)

and

For thus says the LORD, who created the heavens (he is God!), who formed the earth and made it (he established it; he did not create it empty, he formed it to be inhabited!): "I am the LORD, and there is no other. (from Isaiah 45:18 ESV)

How are these sentences, written millennia apart, related? The first sentence refers to one of many recent scientific discoveries that shows us that the earth was especially created in order to be inhabited by creatures like us. It thus confirms the second sentence.

What does the first sentence even mean?

The first sentence is referring to the fact that our planet Earth and other planets in our own solar system go around the Sun in an orbit that is close to being a perfect circle. It’s not a perfect circle. It is actually an ellipse. Sometimes we are just a little bit closer to the Sun and sometimes we are just a little bit farther away. But our distance from the Sun does not change by very much. Our orbit is only a little bit elliptical (another way of saying this is that our orbit is only a little bit eccentric, where eccentricity refers not to being weird, but to deviating from a perfect circle).

It’s easy to take something like this for granted. You might think that of course we go  around the Sun in an almost perfect circle. However, it turns out that we should not take our circular orbit for granted. As scientists have examined the orbits of hundreds of exoplanets (planets that are going around stars other than our own Sun) they have found out that most of them have orbits that are much more elliptical than earth’s. That means that at some points in their orbit they are much closer to their star than at other points. The following diagram illustrates this in a very rough, not to scale, way:

I probably don’t have to tell you why a circular orbit is much better for us than a more elliptical one. But just in case you haven’t thought of it, I’ll explain. All the other planets in our solar system are either too close to the Sun, and thus too hot to support human life, or else they are too far away from the Sun, and thus too cold to support human life. But even if Earth (or another planet around a similar star) was the same average distance from the Sun as it is now, if our orbit was more elliptical we would have extreme temperature variations. Because the amount of solar radiation a planet receives varies with the square of its distance from the star it orbits, relatively small changes in distance can make a big difference in tempterature. If our orbit was a little more elliptical, part of the year much of our planet would have temperatures similar to the hottest days in Death Valley. At other times in the year much of the planet would have temperatures similar to Antarctica in winter. Such a planet might be a descent host for creatures like bacteria and some aquatic creatures, but it would not make a good home for you and me.

Thus, modern science can help us see even more clearly than the people in Isaiah’s day could see just how special the earth is. By implication we can also see God’s great power, intelligence, and wisdom that allowed Him to create a home planet for us that is just right in many ways. Our planet does not merely allow life to barely exist, our planet thrives with a lush biosphere full of a vast multitude of creatures.

A Lot More than the Right Kind of Orbit

There are many other ways in which God made our planet to be just right to serve as a home for us. It is like a “goldilocks planet” that is neither too far nor too close to the Sun, it orbits around a type of star that works well for supporting life, and earth is neither too big (Jupiter!) nor too small (Mars!) to have just the right kind of atmosphere for us to breath. Further, our planet is blessed with a moon that stabilizes our tilt, a strong magnetic field that protects us from harmful radiation, and a solar system where a large Jupiter-sized planet is in a good location to reduce the number of devastating asteroid impacts we experience. You can read more about this in a related blog post: God Created the Earth to Be Inhabited.

Practical Applications

Besides being intellectually interesting (at least to some of us), does the fact that modern science has shown earth to be a rare and special planet exquisitely designed for creatures like you and me to live on have any practical implications? Yes!

First, these facts should move us to worship and give thanks to our great, wise, powerful Creator! The failure to recognize that we have such a Creator and the subsequent failure to worship Him is at the very root of human problems and suffering (see Romans 1:18-32).

Second, seeing how great our God is should lead us to trust Him with problems that may seem big to us, but are small to Him. If He can make the right kind of planet with the right kind of orbit, He can help you with all the problems you face: temptations, relationship problems, the need for guidance, provision, sickness, facing opposition, and more. Further, the fact that He cared to make this planet as a great home for you points to the truth that He cares about you and your life and your wellbeing. Of course, this truth is seen even more clearly at the cross, where the One who made the Earth for us to live on came to save us from our sins so we can live forever with Him on an even better New Earth!

 

Summary: God made the earth with a good circular orbit, so we should worship Him and trust Him! Hallelujah!!

 

 

Hebrews 13:16 And do not forget to do good and to share with others . . .

 

For Further Reading and/or listening:

1.) I got the idea to write this blog post by listening to a fascinating discussion between two really smart scientists who are also devoted Christians. In that discussion, one of them briefly mentions that most exoplanets have orbits that are more elliptical than earth’s orbit. You can listen to them, too. Here is the video:


 

2.) There are (at least) two whole books on the topic of how special the earth is and the many factors that make it a good home for us. The two books are:

 

Rare Earth, Why Complex Life is Uncommon in the Universe

 

The Privileged Planet, How our Place in the Cosmos is Designed for Discovery

 

3.) I have a whole series of blog posts about scientific evidence for God. Here are some of them:

 

How viruses strengthen the scientific case for a Creator

 

God Created the Earth to be Inhabited

 

How the Sun glorifies the Son


Nuclear Submarines and Living Cells


Octopi from Outer Space

Behe’s Three Mighty Blows Against Darwinism

How the Smallest Cells Give BIG Evidence for God


4.) I also have blog posts on lots of other stuff. Here’s a small sample:

Sunflowers and Sonpeople

Mark’s Resources on Hell


Create in Me a Clean Heart, O God

 

What does Paul Mean by a “Spiritual Body”?

 

The Three Ways Jesus Saves Us from our Sins

 

A Model for Intercessory Prayer

 

Foot Theology

 

Practical Advice for Battles with Sin and Temptation

 

What’s so Great about the Great Commission?

 

Because the Days are Evil

 

Do we Kneel and Bow Down Enough?

 

The Book of Revelation is Practical and Applicable