Chris Kempes

And what if you used a smaller molecule than lipids? And so one can really absolutely start to play that. And this is a place actually where we're separating the contingencies of evolution from what might be truly universal.

And what if you used a smaller molecule than lipids? And so one can really absolutely start to play that. And this is a place actually where we're separating the contingencies of evolution from what might be truly universal.

So yeah, if you could find a smaller enclosure that does all the same things that our membrane does in terms of it's flexible enough, it keeps the inside separated from the outside, it has the right sort of hydrophobicity, all those sorts of things. Yeah, there's certainly molecules that would be thinner in a layer. And then yeah, you probably could get a little bit smaller.

So yeah, if you could find a smaller enclosure that does all the same things that our membrane does in terms of it's flexible enough, it keeps the inside separated from the outside, it has the right sort of hydrophobicity, all those sorts of things. Yeah, there's certainly molecules that would be thinner in a layer. And then yeah, you probably could get a little bit smaller.

So I think this is a case where We think we understand the constraints that matter, why the smallest cells on Earth are the smallest they can be. And then we could play a little bit of games with chemistry to say, how much could you push that lower limit in size? In fact, that game was was played a bit because the Allen Hills meteorite, which was this meteorite from Mars.

So I think this is a case where We think we understand the constraints that matter, why the smallest cells on Earth are the smallest they can be. And then we could play a little bit of games with chemistry to say, how much could you push that lower limit in size? In fact, that game was was played a bit because the Allen Hills meteorite, which was this meteorite from Mars.

Where under a microscope, people thought they were seeing structures that really looked like cells or the remnants of cells or some sort of precipitate from a cell. And this is famous in the astrobiology community because Bill Clinton gave a press conference saying he might have potentially found life on Mars or evidence of life on Mars. I think infamous is the word you're looking for, not famous.

Where under a microscope, people thought they were seeing structures that really looked like cells or the remnants of cells or some sort of precipitate from a cell. And this is famous in the astrobiology community because Bill Clinton gave a press conference saying he might have potentially found life on Mars or evidence of life on Mars. I think infamous is the word you're looking for, not famous.

Yeah. You're right. I forgot my prefix. But this, because of how big a news story this was and the implications, the National Academies put together one of these National Research Council reports. where they gathered experts from paleontology and biophysics and biochemistry to try and say, are these things too small?

Yeah. You're right. I forgot my prefix. But this, because of how big a news story this was and the implications, the National Academies put together one of these National Research Council reports. where they gathered experts from paleontology and biophysics and biochemistry to try and say, are these things too small?

So one of the initial sort of critiques was, yeah, but these structures are really small. They're smaller than the smallest cells we see. Are we actually talking about fossils here? And so in this report, which is really wonderful, people work through all these different angles to say, yeah, this is probably too small. So people work through, okay, what's the...

So one of the initial sort of critiques was, yeah, but these structures are really small. They're smaller than the smallest cells we see. Are we actually talking about fossils here? And so in this report, which is really wonderful, people work through all these different angles to say, yeah, this is probably too small. So people work through, okay, what's the...

what's the most curvature you could get from some polymer or some sort of molecule? And are these things below the curvature radius for that molecule such that we don't think you could actually encapsulate with molecules at this scale? And then there's all sorts of other rich material in that report. And basically every paper in this report says these are too small.

what's the most curvature you could get from some polymer or some sort of molecule? And are these things below the curvature radius for that molecule such that we don't think you could actually encapsulate with molecules at this scale? And then there's all sorts of other rich material in that report. And basically every paper in this report says these are too small.

But this is exactly the game that we have to play to try and understand what we might be looking at somewhere else.

But this is exactly the game that we have to play to try and understand what we might be looking at somewhere else.

That's a great point. Yeah. I mean, you could even play a – I don't know if we have an astrobiology for other universes yet. But you could play that game. You could say, you know, imagine you were in a universe where the atoms were smaller.

That's a great point. Yeah. I mean, you could even play a – I don't know if we have an astrobiology for other universes yet. But you could play that game. You could say, you know, imagine you were in a universe where the atoms were smaller.

Yeah, exactly. Assuming you can still get all the other physics you need, what's the smallest possible cell in such a universe?

Yeah, exactly. Assuming you can still get all the other physics you need, what's the smallest possible cell in such a universe?