“Yes, we’re saying that now. We’ve also been saying it decades before now, so yes, we’re still saying that now.”
-Irritated, tired researchers
Here’s the thing. We actually have NO idea what to look for. Our sample size of “planets that have life” is exactly one, which doesn’t really tell us much. Since we know that an Earth-like planet can support life, it makes sense to start our search there, but there’s no reason to believe that extraterrestrial life might not be completely and utterly different from anything on our little rock.
That being said, liquid water is extremely conducive to complex chemical reactions, which are probably required for complex life. But you also need chemicals that are both reactive enough to do things, but can be stable enough to not randomly break apart. This is one of the reasons carbon is so good at being alive, it’s reactive enough to bond with a lot of other elements (including itself), but not too reactive to be useful.
So basically, this isn’t new. It’s just pointing out that a pure “water world” might not be very useful without a bunch of lively chemicals to boot.
There’s also the ubiquity of certain elements/compounds.
We look for carbon-based because of the ubiquity of carbon. Is life (or anything) more likely to occur based on the most ubiquitous chemicals or the most rare chemicals.
Simple odds.
Uh… I’ve been hearing about spectroscopic analysis searching for organic compound for years now. This isn’t some gotcha that scientists forgot to look for
Doesn’t even need water…
A fluid medium helps, but it never had to be water. Whatever the medium is, any life that evolves would adapt to it.
This is more about finding water so we can move humans there
I agree this is true for the search for extraterrestrial life, but I don’t think humans are gonna evolve quick enough for anything but water to cut it
Water isnt just any old fluid medium, it has a lot of important properties.
It has important qualities to us because we evolved to exist in it as a medium…
If life evolved in liquid methane, then methane would have important qualities that we’d think are needed.
Like, that was the whole point of my comment
But I disagree. Water is special and unique. You can’t just swap it with a random liquid and have the same support for life.
As we know it…
I’m sorry I can’t explain this in a way that helps you understand
I understand your meaning. Life “as we know it” is a narrow view of what possibilities there may be for life. And there may absolutely be some kind of life that is built on other materials. At the same time, water (and carbon) have particular chemical properties that make them fundamentally important for building stuff from molecules in general, that goes beyond “we only use those cuz they happened to be here”
Yep, only for life as we know it (and we have a sample size of exactly 1)
Food can be grown or hydrated. We need minerals for nutrition.
