Jun 25, 2023 02:43 PM
https://www.sciencealert.com/radical-new...at-life-is
EXCERPTS: . . . But if life is elsewhere in the universe, it may not be made of the same stuff as us. It might not look, move, or communicate like we do. How, then, will we identify it as life?
Arizona State University astrobiologist Sara Walker and University of Glasgow chemist Lee Cronin think they've found a way. They argue that chance alone cannot consistently produce the highly complex molecules found in all living creatures.
To produce billions of copies of intricate objects like proteins, human hands, or iPhones, the universe needs a 'memory' and a way of creating and reproducing complex information – a process that sounds very much like 'life'.
"An electron can be made anywhere in the universe and has no history," Walker told New Scientist. "You are also a fundamental object, but with a lot of historical dependency. You might want to cite your age counting back to when you were born, but parts of you are billions of years older. From this perspective, we should think of ourselves as lineages of propagating information that temporarily finds itself aggregated in an individual."
Walker and Cronin's 'assembly theory' predicts that molecules produced by biological processes must be more complex than those produced by non-biological processes.
To test this prediction, their team analyzed a range of organic and inorganic compounds from around the world and outer space, including E. coli bacteria, yeast, urine, seawater, meteorites, drugs, home-brewed beer, and Scottish whisky.
[...] While some compounds from living systems had less than 15 assembly steps, no inorganic compounds made it above this threshold.
"Our system … allows us to search the universe agnostically for evidence of what life does rather than attempting to define what life is," Walker, Cronin, and others wrote in a 2021 Nature Communications article... (MORE - missing details)
EXCERPTS: . . . But if life is elsewhere in the universe, it may not be made of the same stuff as us. It might not look, move, or communicate like we do. How, then, will we identify it as life?
Arizona State University astrobiologist Sara Walker and University of Glasgow chemist Lee Cronin think they've found a way. They argue that chance alone cannot consistently produce the highly complex molecules found in all living creatures.
To produce billions of copies of intricate objects like proteins, human hands, or iPhones, the universe needs a 'memory' and a way of creating and reproducing complex information – a process that sounds very much like 'life'.
"An electron can be made anywhere in the universe and has no history," Walker told New Scientist. "You are also a fundamental object, but with a lot of historical dependency. You might want to cite your age counting back to when you were born, but parts of you are billions of years older. From this perspective, we should think of ourselves as lineages of propagating information that temporarily finds itself aggregated in an individual."
Walker and Cronin's 'assembly theory' predicts that molecules produced by biological processes must be more complex than those produced by non-biological processes.
To test this prediction, their team analyzed a range of organic and inorganic compounds from around the world and outer space, including E. coli bacteria, yeast, urine, seawater, meteorites, drugs, home-brewed beer, and Scottish whisky.
[...] While some compounds from living systems had less than 15 assembly steps, no inorganic compounds made it above this threshold.
"Our system … allows us to search the universe agnostically for evidence of what life does rather than attempting to define what life is," Walker, Cronin, and others wrote in a 2021 Nature Communications article... (MORE - missing details)