Friday, December 16, 2016

Extraterrestrial Microbes and Being Alone in the Universe

A couple of weeks ago I posted some thoughts that I intended to give after a cosmology talk here at UCR. As it happens, I gave an entirely different set of comments! So I figured I might as well also share the comments I actually gave.

Although the cosmology talk made no or almost no mention of extraterrestrial life, it had been advertised as the first in a series of talks on the question "Are We Alone?" The moderator then talked about astrobiologists being excited about the possibility of discovering extraterrestrial microbial life. So I figured I'd expand a bit on the idea of being "alone", or not, in the universe.

Okay, suppose that we find microbial life on another planet. Tiny micro-organisms. How excited should be we?

The title of this series of talks -- written in big letters on the posters -- is "Are We Alone?" What does it mean to be alone?

Think of Robinson Crusoe. He was stranded on an island, all by himself (or so he thought). He is kind of our paradigm example of someone who is totally alone. But of course he was surrounded by life on that island -- trees, fish, snails, microbes on his face. This suggests that on one way of thinking about being "alone", a person can be entirely alone despite being surrounded by life. Discovering microbes on another planet would not make us any less alone.

To be not alone, I’m thinking, means having some sort of companion. Someone who will recognize you socially. Intelligent life. Or at least a dog.

We might be excited to discover microbes because hey, it's life! But what’s so exciting about life per se?

Life -- something that maintains homeostasis, has some sort of stable organization, draws energy from its environment to maintain that homeostatic organization, reproduces itself, is complex. Okay, that's neat. But the Great Red Spot on Jupiter, which is a giant weather pattern, has maintained its organization for a long time in a complex environment. Flames jumping across treetops in some sense reproduce themselves. Galaxies are complex. Homeostasis, reproduction, complexity -- these are cool. Tie them together in a little package of microbial life; that’s maybe even cooler. But in a way we do kind of already know that all the elements are out there.

Now suppose that instead of finding life we found a robot -- an intelligent, social robot, like C3P0 from Star Wars or Data from Star Trek. Not alive, by standard biological definitions, if it doesn’t belong to a reproducing species.

Finding life would be cool.

But finding C3P0 would be a better cure for loneliness.

(Apologies to my student Will Swanson, who has recently written a terrific paper on why we should think of robots as "alive" despite not meeting standard biological criteria for life.)

Related post: "Why Do We Care About Discovering Life, Exactly?" (Jun 18, 2015)

Recorded video of the Dec 8 session.

Thanks to Nalo Hopkinson for the dog example.

[image source]


Susan Schneider said...

Nice post! Another way we could be alone is to find we are likely the only instance of life out there. This could be the case. Finding a distinct form of microbial life would be exciting, suggesting that the conditions for cooking up life are perhaps satisfied throughout the universe. An otherwise empty universe is a lonely universe. All those exoplanets aren't inhabited! We' should fill it with sentience if that's the case...if you ask me,at least.

Unknown said...

I agree microbial life isn't super exciting in itself. But if we're finding it elsewhere, it tips the Bayesian scales in favor of it being reasonably for life to come about. Since simple life has evolved into the kinds of life we do care about for itself once, that it would in some of these other cases of life seems reasonable. In which case we're probably not alone in the universe, just yet to find our universemates.

(I imagine the astrobiologists would be pretty excited about seeing the early stages of evolution on a planet as well. Less history to trace back.)

Eric Schwitzgebel said...

Thanks for those comments, folks!

Susan and Nichole: Yes -- exciting in that way. If there's lots of microbial life and no particular reason to think that microbial life almost never becomes sentient, then that does increase the likelihood that we are not "alone" (in my intended sense of "alone"), but only derivatively in my view, via increasing the likelihood that there is other sentient life out there.

Yes, I too would support the spread of sentience if the universe is otherwise devoid of it.