Wednesday, September 28, 2016

Missionaries to Mars

Every time there's exciting news about space, whether it's missions of exploration, the discovery of new celestial bodies, or an advancement in relevant technology, speculation starts flying about extraterrestrial life. One variant of that you don't see very often popped up in the Wall Street Journal: "Could Aliens Have Souls That Need Saving?"
Post title shamelessly stolen from Albert Mohler.
(If you don't have access to the WSJ, the discussion of said article over at Get Religion is worth reading.)

The question at hand: If alien life were discovered, would Christians have to share the Gospel with them? It's not a new question, although it's usually expanded to consider the role of cosmology in Christian theology as well. CS Lewis wrote a series of books about it, for example.

There's a few ways of looking at this.

  • The positive case would state that, since Adam's sin caused the Fall to ripple out through all of creation, then aliens would also be in need of redemption. 
  • The negative case would state that, since any alien life would not be descended from Adam, they would not be inheritors of Adam's sinful nature and thus not bound by the details of Christian theology. 
  • The demure case would state that, since the Bible says nothing, positive or negative, about life beyond Earth, then speculation about the theological ideas surrounding it is improper. 
Dr. Mohler argues the latter case, incidentally. 

As for me, I'm a contrarian on this topic. The question is hypothetical, but I'm convinced that the possibility of alien life is so poor that it's not worth taking seriously. Allow me to explain.

Deconstructing Drake

If you've never heard of the Drake Equation, it's a speculative equation for calculating the probable number of planets with communicative, extraterrestrial civilizations. It suffices for the sake of this discussion. The terms of the equation (per Wikipedia):

  • R* = the average rate of star formation in our galaxy
  • fp = the fraction of those stars that have planets
  • ne = the average number of planets that can potentially support life per star that has planets
  • fl = the fraction of planets that could support life that actually develop life at some point
  • fi = the fraction of planets with life that actually go on to develop intelligent life (civilizations)
  • fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
  • L = the length of time for which such civilizations release detectable signals into space
The product of those terms is supposed to represent the number of extraterrestrial civilizations with which we might communicate. 

The most immediate criticism of the equation is that most of the terms are completely unknowable. This can be seen in the Rare Earth criticism of the equation, which restates the equation in such a way as to emphasize the extreme unlikelihood of these events. It's a lot to restate much of the case there. For example, the extreme galactic radiation and gravitational forces would most certainly prevent life from forming in the galactic center. That's where the highest density of stars in our galaxy lies, so most life would have to form in the less crowded outer sections. Except, it can't form too far out there, because the spiral arms are home to many supernovae that would also disrupt the formation of life. 

In short, Earth rests in a sweet spot, both in our solar system and in the galaxy, but there's only a fraction of the planets in the galaxy in that sweet spot. Of those, how many actually have conditions under which life could develop? I still intend to write a post on the topic alone, but my feelings on the chemical origin of life are . . . not positive. Although there is much speculation on the ability of life to survive in climates very different from Earth, supposedly expanding the "ne" term above, the "fl" term, as far as I'm concerned, is extremely low. Zero, for all intents and purposes. Frankly, by the viewpoint of scientific naturalism, life shouldn't even exist on Earth, much less any other planet. 
"Hospitable" climates like this aren't particularly common.

For all practical purposes

Perhaps I'm being overly critical of a hypothetical situation. What if alien life actually did exist on other worlds? 

It actually wouldn't make a difference. For all practical purposes, we're alone. 

I explained in my last post on astronomical matters that travel between stars is essentially impossible. Our closest neighboring star, a mere four light years away, would take thousands of years to reach. Even assuming speed of light travel, reaching other planets in the habitable ring of the Milky Way is still a journey of years beyond human lifespans. 

That's not even considering other galaxies, where the distances are measured in millions of light years. 

If we're not visiting other planets, and they're not visiting us, could we at least communicate?

Consider your local radio station. You can't listen to it beyond a certain distance. This is because the signal dissipates as it travels from the broadcast site; eventually, it becomes too weak, too indistinct, to be distinguished over background noise. You could solve this issue by increasing the amount of power put into the broadcast, or you can focus the signal to aim it at a specific location.

This signal dissipation becomes problematic at interstellar distances. Let's take the example of the signal SETI detected back in August. That came from a star system roughly 94 light years away. Here's what was said of the signal at the time:
Based on the received signal's characteristics, aliens would have to generate about 100 billion billion watts of energy to blast it out in all directions. And they'd still have to produce more than 1 trillion watts if they beamed it only to Earth for some reason, Shostak said.
"The first number is hundreds of times more than all the sunlight falling on Earth," he said. "That's a very big energy bill."
To be clear, 1 trillion watts is still an awful lot of energy. It's roughly the entire energy generated in the US for two solid weeks; or, if you prefer, the entire energy output of a modest nuclear bomb. 

The idea of a directed signal is often thought unlikely; after all, you'd have to know the planet was actually there. Even then, the energy needed to directly contact other planets is . . . well, implausible. The bill for contacting something "relatively" nearby, less than 100 light years, is immense. Fancy radio telescopes can't change those numbers. What about something further out than that? 
But can they see why kids love the cinnamon taste of Cinnamon Toast Crunch?

And then a miracle happens

Well, you could start speculating about Dyson Spheres and higher-order Kardashev civilizations, but that sort of stuff is entirely imaginary. The same thing for traversing the distances, much less surviving them. We have to imagine technology that is, by our understanding of the laws of physics, utterly impossible. 

It's entirely premised on the idea that these civilizations would be much older than ours, and that by merit of their age, they've somehow learned far more than us. After all, our current tech would seem like magic to society a century ago; imagine if a civilization had a million, or even a billion years on us. 

That argument presupposes that our understanding is still insufficient. Not that I'd assume we know all there is to know about everything, but there's only so far you can take that before it gets into fairy-tale understandings of science. It boils down to an argument of, "Well, just because it's practically impossible and we have zero evidence for any of this doesn't mean there isn't a chance it might be true someday."

And they say Christian faith is superstitious nonsense based on blind faith. 

You can mull over the Fermi Paradox as much as you like, but as far as I'm concerned, humans are unique in the universe. Even if we're not, we might as well be. So, no. I don't think it's worth it to fret about the state of alien souls. Don't we have enough theological concerns about life on Earth as it is?

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