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+--- Thread: Article Alien life might not be something science can ever discover (/thread-14793.html)
Alien life might not be something science can ever discover - C C - Oct 8, 2023
Could Earth be the only planet with intelligent life?
https://bigthink.com/starts-with-a-bang/earth-only-planet-intelligent-life/
KEY POINTS: We live in a vast observable Universe, with sextillions of stars and even larger numbers of planets, with more unobservable Universe and potentially even a multiverse beyond what we can see. While the ingredients for life and living planets are seemingly everywhere, however, we have yet to detect a single sign of life beyond Earth — even the simplest forms of life — on any world at all. Is it possible, or even likely, that despite all of the chances out there for intelligent life, planet Earth is home to the only instance of it in all of reality? Today, these are questions that no scientist can answer, but a great many scientists are working to uncover the evidence for, one way or another. Even if all we found was a world with microbial (or even simpler) life — which we fully expect should be the most common circumstance among all inhabited planets — we’d learn that Earth is not unique, and that life really is out there in the Universe... (MORE - details)
Alien life might not be something science can ever discover
https://aeon.co/essays/alien-life-might-not-be-something-science-can-ever-discover
EXCERPTS: ... ‘No single effect, experiment, or paper provides definitive evidence about its claims. Innovation identifies possibilities. Verification interrogates credibility. Progress depends on both.’ So opens the ‘Community Report from the Biosignatures Standards of Evidence Workshop’ (2022), quoting an earlier paper. The effects in question are not astrobiological: the quoted paper is from cancer research. But this is how all science works. Cumulatively, in small steps, on the shoulders of giants, and in fits and starts. It’s a process the public seldom sees. Nor does it match the story we’re usually told with its litany of heroes – Newton, Copernicus, Darwin, Einstein: men who saw beyond their era’s paradigm to glimpse a revolutionary new worldview, bringing it to humanity like Prometheus (but without the punitive price tag).
[...] A 2018 paper in the journal Astrobiology introduced a tool called ‘The Ladder of Life Detection’ that synthesises our understanding of life and our ways of detecting it into a framework for determining what combinations of evidence could be sufficient to ‘preclude any abiotic interpretation’; that is, to say not It is life but rather It couldn’t be anything else. The authors organised their criteria not by the potential to definitively prove life but ‘to convince a majority of the scientific community’. After all, life exists or it doesn’t – whether observed by humanity or not. What science changes is our collective knowledge. The threshold is consensus.
It seems like it should be simple. You have no trouble telling what’s alive from what’s not. A cat versus a rock, a tree versus water. You can recognise what might be called ‘technosignatures’ too, proof of intelligent life’s material manipulations: a car exhaust, a cell phone, a city grid. But astrobiologists say things like: ‘The detection of extraterrestrial life in our solar system and beyond will likely be neither instantaneous nor unambiguous.’ Or they write: ‘Evidence of life may be subtle or unfamiliar, and reveal itself only in stages, as one observing campaign informs the next.’ Aren’t they supposed to be smarter than us? They’re not exactly rocket scientists, but they’re in the department next door.
The problem is, you and I and the scientists are good at recognising Earth life. And big life, too. But scoop up a cup of seawater – or a slice of Antarctic ice – and it becomes much harder to determine what’s living. Even our intuition for habitable environments has been bested by microbial ingenuity, by extremophiles revealing the provinciality of our instincts. Then there’s viruses. Are they alive or not? You see how it gets tricky. Add to the mix trying to figure out all this from afar: with a remote-control robot on Mars, or a snapshot of a spectral reading of an exoplanet’s atmosphere, and you see that astrobiologists are trying to answer one of humanity’s biggest questions with something like a shadow show... (MORE - missing details)