Mediocrity and Life on Earth
Oct. 6th, 2021 05:22 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
ysabetwordsmithI was amused by this article about mediocrity and life. Apparently, people who think that life is common in the universe tend to use the argument that a given example is more likely to be a common trait than a rare trait, which is mathematically reasonable but will sometimes be the wrong guess.
I do rather the opposite. I look at the fact that life has swarmed all over this planet, including some exceedingly hostile places (solid rock, boiling water, ice, etc.) and conclude based on this hard evidence that life is extremely good at gaining a toehold in harsh conditions. Plus the fact that it managed to survive flipping the whole atmosphere during the Great Farting Oxygen Event. So life is likely to be common, because there are lots of places in the universe. But most of it will resemble the kinds of life found in those harsh conditions: algae, lichens, brine shrimp, ice worms, tardigrades, etc. Not terribly exciting unless you are a xenobiologist or other nerd. A complex ecosystem supporting advanced life needs a more hospitable environment. Still, life is creative, and what it finds hospitable enough to build a biosphere will not always necessarily look like Earth. It is worth seeking Earthlike planets because we know this type can support a biosphere, but that doesn't mean it's the only option. Nature is much, much more creative than most humans with the exception of some of the best worldbuilders.
I do rather the opposite. I look at the fact that life has swarmed all over this planet, including some exceedingly hostile places (solid rock, boiling water, ice, etc.) and conclude based on this hard evidence that life is extremely good at gaining a toehold in harsh conditions. Plus the fact that it managed to survive flipping the whole atmosphere during the Great Farting Oxygen Event. So life is likely to be common, because there are lots of places in the universe. But most of it will resemble the kinds of life found in those harsh conditions: algae, lichens, brine shrimp, ice worms, tardigrades, etc. Not terribly exciting unless you are a xenobiologist or other nerd. A complex ecosystem supporting advanced life needs a more hospitable environment. Still, life is creative, and what it finds hospitable enough to build a biosphere will not always necessarily look like Earth. It is worth seeking Earthlike planets because we know this type can support a biosphere, but that doesn't mean it's the only option. Nature is much, much more creative than most humans with the exception of some of the best worldbuilders.
(no subject)
Date: 2021-10-07 12:27 am (UTC)But the article has a good point too.
Until we figure out how to go from early Earth with a reducing atmosphere, and few organics to the first cellular life, we can't say who easy it is and thus how common life might be.
We have evidence that once things get started, they tend to persist in even in majorly hostile environments.
But it's those steps from "non-life" to "life" that will determine how common life-bearing planets are.
I'd not be surprised if there are multiple ways to get from "non-life" to "life". Even ones for conditions *very* different from those on Earth. But we are even less likely to figure what those are before we encounter such life.
As Ben Bova pointed out 50 years ago, Stellar formation sets some constraints on the possibility of life. First generation stars? Nope.
Second generations stars, maybe, but it'd be *very* different from life as we know because of elemental distribution. (Earth would be a toxic waste dump to such life forms, because of the common elements here that would be rare to non-existent on their worlds). Also, they'd be around 5 billion years older than we are, so they might not even notice us.
Third generation stars. Yep, Sol is one. Only thing is, it's one of the oldest third generation stars in the neighborhood. That means that *we* may be the "older and wiser race" so oft seen in SF. Assuming we don't exterminate ourselves that is.
scary thought that.
ps. I know of exactly *one* SF novel that uses the idea of creatures creatures from a second generation star. The Ring of Ritornel
Thoughts
Date: 2021-10-07 01:05 am (UTC)It doesn't have to be easy. It just needs plenty of opportunity. Imagine that you get to roll the dice for "life occurs" once per year per stellar body that has some precursor chemicals on it. That is a LOT of chances.
And one way to flip from a reducing atmosphere to an oxidizing atmosphere is photosynthesis, like what happened here. Granted, that relies on tiny life discovering that particular superpower, but the general inclination is to use available resources, so again it's just down to rolling the dice, and evolution is a real dice whore.
>>But it's those steps from "non-life" to "life" that will determine how common life-bearing planets are.<<
That's only if it stays put. Considering the way we've seen this planet's life colonize most of the surface, and oh yes, hitch rides into space on our equipment, I'm betting some life finds ways to travel, accidentally or on purpose. I also think it's more likely for said travelers to be more like tardigrades than stage trees, but admit the stage trees were a logical extrapolation from extant examples.
>> I'd not be surprised if there are multiple ways to get from "non-life" to "life". <<
Well, there has to be at least one per core material, because those tend to require different setups. Like here, we have carbon-based life, but silicon-based life has been proposed, and so on. You might get more variations. Life emerging on the surface of a planet likely has a different spark starting it than life emerging around black smokers or other subsurface areas. But you need at least one per core material.
>> Even ones for conditions *very* different from those on Earth. But we are even less likely to figure what those are before we encounter such life. <<
It's just easier if you have more examples. People have been trying to create life for, gosh, thousands of years now. That's not very long on an evolutionary scale, but humans are smart. It won't surprise me if someone figures it out.
>>As Ben Bova pointed out 50 years ago, Stellar formation sets some constraints on the possibility of life. First generation stars? Nope.<<
Certainly not life as we know it. Far as we know, it took a while to chain up from hydrogen and helium to heavier elements. Planets are made from the bones of dying stars; this is the heaven of stars and we are star angels, here were everything is bright and warm and close enough to touch. I would not, however, assume that we know everything about what happened in the early universe or what is possible or what life can do.
>> Also, they'd be around 5 billion years older than we are, so they might not even notice us. <<
Well, yes, species have a lifespan. They would likely grow up and either go extinct, evolve into something else, or otherwise move on in that timespan. Probably a lot of different generations even. But that would also leave quite a lot of time for even one such species to think of sowing life seeds around, and by this point there would be little or no evidence of it except for life being around. *chuckle* Especially if their star tractor was sufficiently advanced that humans mistook it for a natural phenomenon, which seems likely.
>> scary thought that. <<
No shit.
>> ps. I know of exactly *one* SF novel that uses the idea of creatures creatures from a second generation star. The Ring of Ritornel <<
Interesting.
Re: Thoughts
Date: 2021-10-07 01:44 am (UTC)Seeding life would explain how most scifi stories have things that are recognizably plant/animal...or at least oxygen-compatible. (I mean, really it's that most writers are unimaginative humans, but still...)
Seriously I want more stories that deconstruct that - where's the story that has the alien horrified that we breathe poisonous oxygen, or the methane-based aliens who explode in the stratosphere?
Re: Thoughts
Date: 2021-10-07 02:07 am (UTC)That is true. I mean, come on, humans started out thinking that stars and planets came in fairly limited sets, and we're finding new batshit crazy versions every day, including things we can't even explain how they exist. Why would life, which is already full of batshit crazy diversity, be different?
>> Seeding life would explain how most scifi stories have things that are recognizably plant/animal...or at least oxygen-compatible. (I mean, really it's that most writers are unimaginative humans, but still...) <<
Plenty of authors tip the panspermia theory on purpose to make that easier.
>> Seriously I want more stories that deconstruct that - where's the story that has the alien horrified that we breathe poisonous oxygen, or the methane-based aliens who explode in the stratosphere? <<
Right here. There are others, but that's some of the best I've found.
I enjoy writing really far-out speculative fiction, and I love using hard science to inspire it. The problem is ... most of the potential readers are human, and therefore limited in what they can grasp let alone find entertaining. So in addition to the difficulty imagining such things, there is also the difficulty selling them, which pushes down the number available.
Enter crowdfunding! As long as author and sponsor are interested in similar things, anything at all can be created and released.
Re: Thoughts
Date: 2021-10-07 03:00 am (UTC)>>I enjoy writing really far-out speculative fiction, and I love using hard science to inspire it. The problem is ... most of the potential readers are human, and therefore limited in what they can grasp let alone find entertaining.<<
What about doing something where the alien's normal is very odd for humans...but the human protagonist not a standard human? I.e.
Blindness:
- the aliens live in a begged world and communicate with echolocation and music
- the aliens live in tunnels, or underwater (especially below where sunlight is visible)
Agoraphobia:
- anything based on tunneling or cave species
Deafness:
- beelike (communicate by pheromones and dance) likely much easier to parse if you are alert to body language
- Someone with that RIP Van Winkle sleeping disorder might get along decently with hibernateers...unless they think he's got the alien version of non-24 sleep disorder
- A Mad Artist might love trying to communicate with cuttlefish-like aliens by painting (and I have RL communicated with doodles)
Alternately, maybe writing it as a sort of nature documentary or, like, lived experience, rather than the usual script-of-interactions that most stories are. If I'm interacting with a person, that usually has a different feel than interacting with an animal, a tree, a landscape, the divinity/universe, with the divergence getting bigger each time.
(no subject)
Date: 2021-10-07 02:53 pm (UTC)I believe there are planets out there with life on them, I think it's a mathematical certainty based on the number of stars out there. The big question is whether we'll ever develop the tech to get out there and find them. Whether they can evolve up to intelligent life, and whether that life can evolve to the space-faring level is a whole other series of discussions. There are, of course, those who think this has probably happened and some of those races have already died off in some of the older parts of the universe since we're in one of the younger areas.