How do we find aliens? Perhaps we first unlearn what we know about “life”.

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Clara Moskowitz: This is Clara Moskowitz listening to the Science Quickly podcast from Scientific American. Today we’re going to talk about life as we don’t know it.

Sarah Scoles just wrote an article for us in our February magazine on this subject. Sarah hello

Sarah Scholes: Hello Clara. How are you doing?

Moscow: I am great. Thank you for joining us.

Scales: Thanks for the invitation.

Moscow: So what exactly is life as we don’t know it or as you brilliantly call it in history: LAWDKI.

Scales: Yeah, so I’m glad we like the acronym I just came up with, but I think it’s a conversation about life as we don’t know it. It’s important to talk about life as we know it first, because we really only think of life as life. biology as biology.

But life as we know it is really just a specific example of a type of biology that could exist, you know, where most things kind of breathe oxygen, rely on DNA and RNA for genetic material, and kind of shared what they have what scientists call biochemistry.

And that’s life as we know it and life as we don’t know it… I guess I hesitate to say what it is because the point is we don’t know what it is. It’s something that’s biological but not necessarily based on the same elements, and connections are ways of transmitting information. It’s just something that’s not… it’s not physics, it’s not chemistry, but it’s biology, but we really don’t know anything about it.

Moscow: To the right. It actually hurts your brain when you try to imagine something you’ve never encountered, thought about, or seen before. So when we talk about searching for life in the universe, most searches for extraterrestrial life today are searches for life as we know it or life as we don’t know it?

Scales: Most searches, now and in the past, have involved life as we know it because it is the only example of life we ​​have. So as a starting point, it makes perfect sense. An analogy that the scientists I spoke to use is, you know, if you lose your keys on the street, where the first place you might look is under a street lamp, because that’s where the light is, can you see it. You can recognize it as a key.

But if you’re just fumbling around in the dark, even with your keys there, it’s a lot harder. And so it makes scientific sense to me that this is the place of the scientists would Begin. And so they search the universe for things like fingerprints that could create life similar to us or other animals on Earth if we saw them somewhere else.

But now that we’ve been doing this for a while, scientists are starting to get more creative and think about how they might try to find life that we don’t know, which is very difficult because, like you said, we don’t know anything about it. It’s unfamiliar and unimaginable, I think, one of the sciences told me. And where do you even start?

Moscow: To the right? Total. So what are some of your ideas? How do they search for life we ​​don’t know?

Scales: To the right. Good question. And they thought a lot about it. The general idea is to find out what fundamentally differentiates something living from something that is only relied on, like physics or chemistry. Basically, what constitutes something biological and how would you look for a signature for it? And some of the things they’ve dreamed up so far are looking for connections, molecular connections that are complex and that nature probably wouldn’t just produce on its own unless something living somehow forced it to do so.

Another thing is maybe looking for such concentrations of molecules as little complication points on another planet or on a moon of a planet in the solar system or something.

A third thing is evidence that this energy somehow flows from one place to another, just as things in nature generally like to be in balance. So if you see something that isn’t a balance that has energy flowing in and being used, that could be an indication of life. But these are essentially just guesses. They don’t, but they don’t really do it, it’s a different kind of street light.

Moscow: Hm. It’s cool to think about though.

But that touches on an important point. What is life anyway? How do you define aliveness?

Scales: Everyone would like to know the answer to this question. And in general, scientists don’t quite agree on the definition of life and what makes something alive. There are dozens of different definitions that are somehow equally and differently valid. But there was a scientist who wrote a paper in which he brought all these different definitions together and tried to distill them down to the essence of what it means to be alive.

And at least in his opinion, if you take it seriously, life is just self-reproduction with variations. So essentially something that can make more copies of itself, but copies that are just clones but are a little different. That’s it I think. Although you could probably ask five different scientists and get five different definitions.

Moscow: That certainly fits to describe my three year old and my five year old.

Scales: Not clones of you, right?

Moscow: Not nearly. So do you personally think there must be some form of extraterrestrial life out there somewhere?

Scales: You know, for most of my life I thought there just had to be something out there. The universe is so big. We now know that there are so many planets with so many different conditions. Many of these could be habitable for a life like ours. And so in the past I just thought, yeah, statistically of course there must be life out there.

But as I’ve learned more and worked on articles like this and spoken to people who are biologists and not just astronomers, they’re a little hesitant. You know, life here evolved from physics and chemistry became biology. And we don’t really know how that happened. And so we don’t know how hard it is. We don’t know how likely it is.

And even if there are trillions of planets in the universe, we don’t really know that the odds of life arising are greater than one in ten trillion or something. So my new stance is that I don’t know and I don’t make assumptions. I’ll wait for people like these researchers to collect more data and then revise my conclusion.

What do you think?

Moscow: That sounds very wise and prudent. I, I mean, I still hear the echoes of Jodie Foster’s character on Contact saying if there’s nobody out there, it’s just a terrible waste of space. So I. I hope so. I feel like I have hope in life. But as you point out, you know, it’s kind of fascinating either way.

I mean, if we were the only example, that would be just amazing. But even the thought of what life might be like out there feels incredible.

Scales: Yes. Yes. I think each answer is really quite impressive. I’d prefer to have some alien cousins, but when they’re not out there I can kind of get used to being alone in the universe too.

Moscow: Agreed. Well thank you for joining us Sarah and for writing the great article. So, I encourage everyone to read this to learn much more interesting details.

Scales: Thank you very much.

Moscow: For Scientific American Science. Quick, I’m Clara Moskowitz.

Science Quickly is produced by Kelso Harper, Tulika Bose and Jeff DelViscio. Our theme music was composed by Dominic Smith.

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