Hello, friends!
I have only recently returned to regular blogging, and in several recent posts I’ve alluded to the fact that I’m planning to take my Sci-Fi writing in a new creative direction. A lot of things are changing for me right now. A lot of the things I’m doing (or trying to do) are new. With that in mind, I feel like this is a good time to restate some of my views and beliefs about science and the universe, starting with my views and beliefs about extraterrestrial life.
When people ask “Do you think we’re alone in the universe?” I get slightly annoyed by that question. It’s too big a topic to reduce to a simple yes or no question. In Humanity’s search for extraterrestrial life, there are really three kinds of life we might find out there:
Microbial Life: Almost as soon as Earth existed, terrestrial microorganisms existed, too. Microbes developed so swiftly and so easily on this planet that the same thing must have happened elsewhere. For this reason, I believe extraterrestrial microorganisms are plentiful across the cosmos.
Multicellular Life: Complex multicellular organisms—fish, plants, bugs, etc—exist on Earth due to a happy accident. About 2.4 billion years ago, some of Earth’s microbes started burping up oxygen. To those microbes, oxygen was a waste product, but that waste product could also be used in biochemical reactions to create energy. Lots of energy. Enough energy to make complex multicellular life possible. If multicellular life requires this sort of happy accident in order to exist, then I suspect multicellular life must be rare across the universe.
Intelligent Life: I’m going to define intelligence as the ability of a species to make and use tools, to communicate complex ideas, and to generally improve upon its knowledge and technology over time. As far as we can tell, life like that only evolved one time on our planet. Given the vastness of the entire universe, I think intelligent life must exist elsewhere, but I also think it must be extremely rare.
Some time around 1950, nuclear physicist Enrico Fermi famously asked “Where is everybody?” in reference to alien life. As Fermi saw it, advanced alien civilizations should be out there, and their activities in space should be obvious to us. And yet when we look out into the universe, we see nothing. This apparent contradiction—aliens should be everywhere, and yet they seem to be nowhere—is today known as the Fermi Paradox.
So I guess my answer to questions like “Where is everybody?” or “Are we alone in the universe?” depends on what kind of alien life we’re talking about. If we’re talking about alien microorganisms, I think they’re plentiful, and I think it’s only a matter of time before we find evidence of alien microbes on Mars or on one of the icy moons of the outer Solar System. If we’re talking about multicellular life, that sort of life is rare. And intelligent life must be rarer still—so rare, in fact, that our nearest intelligent neighbors may be hundreds, thousands, or even millions of lightyears away.
But these are just my opinions. My opinions about this topic have changed over time, and as I keep learning, my opinions and expectations will, no doubt, change again.
So, friends, what are your opinions and expectations concerning extraterrestrial life? Do you think I’m on the right track, or is there something I’ve missed that you think I should learn more about?
Planet Pailly 
We don’t know until we do, I think… but it’s a great question. I like it…
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That’s true, we really don’t know. But a little speculation can be fun.
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I suspect your about right, and that all we’ll find in our own solar system is microbial. Here’s another question: would finding microbial life have any significant effect on humanity? I’d be thrilled, and yet, what I have for breakfast tomorrow wouldn’t change. But I’m a secular person.
Would things change for religious persons? I’m thinking… no. I’ve read that part of the reason The Church attacked Galileo was the fear that people would lose faith in God (or maybe, in The Church) if they knew Earth orbited the Sun. How silly. Religion is still going strong. What do you think: Will discovering microbes in space have no more of an effect than finding microbes in the deep ocean or anywhere else we explore?
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I seriously doubt that kind of discovery would damage religion, except maybe the more fundamentalist versions. But it might cause it to evolve, which wouldn’t be new. Christians today don’t believe the same things as Christians prior to Copernicus, for instance, that heaven existed behind the starry firmament (literally the heavens) and hell within the Earth.
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I don’t know… a few months ago I got bombarded with troll comments about the firmament, including a very creative comment explaining that the Space Shuttle Challenger exploded because it flew too high and hit the firmament.
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Ugh. We do live in a world with flat earthers, conspiracy theorists, and a lot else. Maybe I should have stipulated “mainstream”.
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To be fair, I’m not always sure when people like that are being serious. Some of them surely are, but some of them are just trying to have their own idea of fun.
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Interesting question. I know a guy who refuses to accept general relativity or a finite speed of light, because of his religious beliefs. That was a long conversation, and I still don’t fully understand how relativity and the speed of light could possibly threaten a person’s faith. Anyway, according to this person, pretty much any scientific fact that contradicts his worldview is atheist propaganda. So if the discovery of alien microbes threatens anyone’s religious views, I suspect they’ll write that discovery off as atheist propaganda, too.
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We’ve had many conversations about this, so you know my view aligns with yours. Totally agreed across the board.
I’m currently listening to a podcast (Universe Today) where there’s a discussion about “The Great Filter”, along with hand wringing about whether we would survive it. Myself, I don’t think there is any one great filter, but a whole bunch of cumulative ones.
Oxygen producing photosynthesis, its later atmospheric buildup due to saturation of the geology (just in time, 600 mya, for the Ediacaran and Cambrian), eukaryotic cells, sexual reproduction, etc.
And then there’s the apparent fact that we spent most of the window for life on this planet getting to this point. The sun’s expected to make things too hot and dry in another 500-1000 million years. If evolution were 10% slower, we might never have existed.
With all that, it would be pretty surprising if the universe were teeming with civilizations.
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That’s a good way to put it, that we had to survive multiple great filters to get to this point. And hopefully we’ll manage to survive at least one more!
I’ve been listening to a podcast called Stories from Space, which has also been talking a lot about SETI, the Fermi Paradox, and so forth. One of the guests made an interesting, though somewhat morbid, analogy.
He said it takes a combination of six rare mutations to cause a cell to turn cancerous. That makes cancer an extremely rare event, for any one cell, but in each human body, there are so many individual cells that it’s almost inevitable to happen to at least one of them, sooner or later.
In a similar way, it may take five or six extremely rare events in order for a planet to develop intelligent life. But given how many planets there are in our galaxy, it’s bound to happen at least one time somewhere.
Again, it was a rather morbid analogy. I’ve lost good friends to cancer, so I don’t take the subject lightly. But otherwise, I thought it was a pretty good analogy.
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I’m good with morbid analogies. I lost my mom and many other relatives to cancer, but don’t see that as taking it lightly.
I guess it comes down to just how rare each of the necessary prerequisites are, which of course gets into what the Drake equation is all about. Someone I read years ago pointed to an elephant trunk as an example of something that doesn’t evolve often. There are various examples of proboscis out there, but the trunk seems unique to a particular part of the evolutionary tree, without convergence. The idea is that maybe a civilization producing intelligence is like the elephant trunk.
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That makes sense. As far as we know, intelligence has only evolved one time on this planet. Maybe it happened twice (the Silurian hypothesis says), but that would still make it a very rare evolutionary event. Meanwhile, how many different ways did eyes evolve on this planet? Or wings? Or flippers?
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From time to time, unusual astronomical discoveries are made and the cry is always “Aliens” – but it never is. Tabby’s Star and Oumuamua both come to mind.
There is only one correct answer to the question “Are We Alone in the Universe?” – and that is : we don’t know.
We have searched but collected no credible evidence so far.
All we have is hope that SETI will one day strike gold.
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Even when those discoveries don’t turn out to be aliens, there’s still a lot of interesting science to be learned. I’m thinking of Jocelyn Bell Burnell’s discovery of LGM-1 (little green men #1), which turned out to be the first known radio pulsar. So even if we never find aliens, if we keep looking, we may find all sorts of other interesting things.
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I guess that the great filter is that technological advancement always outpaces evolution. Which is to say aliens always develop the ability to nuke themselves into extinction before evolving the ability to know not to do that.
This gave me the idea of an alien species who developed space fairing technology over the course of millions of years purely by evolving an instinctual knowledge, but they’re actually very stupid beyond that. Hence, they could pass the great filter.
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That’s a fun idea. Are you using that for a story, or do you have some other plans for this alien species of yours?
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