The glory of God and the Copernican Revolution(s)

Finishing the academic year, the last chapter I taught in our astronomy course was about astrobiology (possible life elsewhere in the universe). One person on Twitter joked with me that this chapter must be very short, something like:

ASTROBIOLOGY

None yet!

Check back later.

THE END

And indeed, it was a pretty short chapter! (Although if you’re interested, Jimmy Akin has a nice podcast arguing that an experiment done by the Viking probes, which landed on Mars in the 1970s, did yield a positive test for life.)

But the author of our book, who far as I know is not a Christian, made the following comment in the chapter.

If and when that day comes [when life is discovered on another world], even if the non-Earthly life is simple one-celled organisms, the discovery will be one of the most important in the history of science. It will complete the journey of human understanding begun in the Copernican revolution of progressive realizations that Earth is not unique.

It’s worth thinking about that, because this is the sort of comment that makes Christians queasy about the advancement of science.

Ptolemy to Copernicus

What’s going on in that quotation first is a comparison of Ptolemaic cosmology to Copernican cosmology. Ptolemaic cosmology, in the form that got his name anyway, was formulated by the Alexandrian astronomer Ptolemy around AD 150. It underwent various tweaks over the years, but the main thing here is that it is a geocentric cosmology - the Earth is stationary, at the center of the universe, and everything else (Moon, Mercury, Venus, Sun, etc.) orbits on spheres moving around the Earth, culminating with the “fixed stars” orbiting just beyond Saturn.

Because the Earth is at the center of the universe in this model, it makes Earth (and so humans) unique. Because Christians have tended to think we are God’s special creation, there was a syncretism between that and Christian belief. And indeed, over time, Christian theology and Ptolemaic cosmology came to be seen as so much of a piece that criticism of the cosmology was seen as criticism of the faith. And surely there is a caution for us in our day there. Scientific theories must be kept open for criticism. Don’t identify any scientific theory so closely with Christianity that criticisms of the scientific claims are interpreted as criticisms of the faith.

Anyway, much later, circa AD mid-1500s, Copernicus comes along and ruins everything (not really), creating a new model in which the Sun is the center of the solar system, much more similar to what we believe is correct today (although Copernicus himself kept many aspects of the Ptolemaic system that have since been jettisoned). But this began what could be called the “Copernican Revolution”, in which (modern secularists would certainly say) we came to realize we just aren’t that special. We’re just another planet in a solar system, whose average star is in a not-that-unique place in a galaxy, which is itself just one of many many galaxies in a huge universe. We’re just that pale blue dot. Eh.

But I want to suggest that, despite all the Christian fears circa AD 1550, the modern understanding gives more glory to God than the old. I was talking with someone about this a couple of weeks ago - Ptolemaic cosmology may have made us “special”, but in that cosmology, the whole universe ended just after Saturn. THE WHOLE UNIVERSE ended just after Saturn. Can we all agree that by modern standards that just seems… pretty small? Like, no wonder it only took God six days, he only had to build a universe out to Saturn, we’ve got our own space probes further out than that now. But no, the present understanding is that the universe is HUGE. Huger than Donald Trump could express. Huger than man would ever be able to explore in the whole lifetime of man. Billions of lightyears across, with around 200 billion galaxies that we can sort of see, each galaxy with billions of stars. Goodness! Well that is to the glory of God. This universe is a work only God could do.

And it’s worth mentioning that, for many of the old Christian scientists, “my new theory gives more glory to God than the old theory” was an argument they made, it was part of their case for the new theory. Or, and related I think, they had a sense that the universe (because it was created by a good God) was a place of proper order, not random, and their new theory gave a better sense of that order than the old. Copernicus made that case himself, in his “On the Revolutions of the Celestial Spheres”:

At rest, however, in the middle of everything is the sun. For in this most beautiful temple, who would place this lamp in another or better position than that from which it can light up the whole thing at the same time? For, the sun is not inappropriately called by some people the lantern of the universe, its mind by others, and its ruler by still others. (Hermes) the Thrice Greatest labels it a visible god, and Sophocles’ Electra, the all-seeing. Thus indeed, as though seated on a royal throne, the sun governs the family of planets revolving around it. Moreover, the earth is not deprived of the moon’s attendance. On the contrary, as Aristotle says in a work on animal, the moon has the closest kinship with the earth. Meanwhile the earth has intercourse with the sun, and is impregnated for its yearly parturition.

In this arrangement, therefore, we discover a marvelous symmetry of the universe, and an established harmonious linkage between the motion of the spheres and their size, such as can be found in no other way.

Astrobiology and life elsewhere

Now, although it was (sort of) relatively easy to discover that the universe extended way, way, way past Saturn, life is going to be much harder. If there is life in our solar system, we’ll probably figure that out relatively soon (if we haven’t already - again, Viking probe data, Martian meteorites and the like have some people thinking we already have). But if we do discover life elsewhere, I don’t think that’s bad for Christianity. It may indeed continue the Copernican revolution… in ways that give even more glory to God. Life on this Earth is already remarkable for its diversity and beauty. Now I don’t know, of course, but maybe someday (soon for microbial life elsewhere in the solar system, or in a long long long long long time for life elsewhere) we’ll find that this life we know about is only a small fraction of the life God made. That would be fine.