4 ms·

Why finding alien life in Universe is now 'only a matter of time'

7 points by mellosouls 3y ago

WheelsAtLarge 3y ago
I have no doubt that it will happen eventually but don't expect it to be intelligent life. It will be the leftover of microscopic life or something very small or if we are lucky it will be live microbes. ET with its own space capsule will not happen anytime soon.
- _hypx_ 3y ago
  If we only find prokaryotic life, that would suggest intelligent life is rare.
  - adastra22 3y ago
    Symbiogenesis has occurred at least three separate times in the history of life on Earth. It is very unlikely to be a great filter.
    - _hypx_ 3y ago
      Twice, not three times. And the second in an organism that already achieved symbiogenesis. All of this took around 2 billion years or so to happen. It is a potential great filter candidate, but we only have a sample size of one. So if it turns out the above set of events is rare, then the prokaryote-eukaryote transition would be a major barrier to intelligent life.
      - adastra22 3y ago
        Three times. There is a very small, not extensively developed branch of life that has a separate primary symbiogebesis event (incorporating cyanobacteria) in the very recent evolutionary past, separate from mitochondria and chloroplasts: https://en.m.wikipedia.org/wiki/Paulinella https://en.m.wikipedia.org/wiki/Paulinella
        _hypx_ 3y ago
        Which would be the third time in nearly 4 billion years. Still pretty unlikely. Both second and third examples are with an organism that already achieved the eukaryotic stage. It's still not clear if the original shift was a likely event.
- prirun 3y ago
  > ET with its own space capsule will not happen anytime soon. Or may have already ready been and gone billions of years ago.
ggm 3y ago
Some gases produced by simple organisms can also have non organic origins. So, ideally it would be complex chemistry to increase the likelihood it's not simpler origins. Finding simpler organism evidence would of course be huge but it would remain a single evidence basis for a long time I think. Finding more distinct complex products would help. Finding RF with a structural asymmetry implying information is the gold standard.
- az09mugen 3y ago
  What about dimethyl sulfide ? https://mashable.com/article/james-webb-space-telescope-exoplanet-discovery-1 https://mashable.com/article/james-webb-space-telescope-exop... EDIT : https://en.m.wikipedia.org/wiki/Dimethyl_sulfide https://en.m.wikipedia.org/wiki/Dimethyl_sulfide
nabla9 3y ago
Over 5,500 planets have been discovered. Once we see clear biosignature gas spectra, we get much better estimate for f_l parameter in Drake's equation (the number of active, communicative extraterrestrial civilizations in our galaxy) The current upper estimate is 10 million (set all unknown probability parameters in Drake's equation to 1.0 and L to infinite.) Setting unknown parameters to even slightly less optimistic numbers drops the estimate dramatically. For example: if you set life develops into intelligence = 0.5 , able to technologically communicate = 0.5, and lifetime = 100k years, you get N=30.

7 points by mellosouls 3y ago

I have no doubt that it will happen eventually but don't expect it to be intelligent life. It will be the leftover of microscopic life or something very small or if we are lucky it will be live microbes. ET with its own space capsule will not happen anytime soon.

_hypx_ 3y ago
If we only find prokaryotic life, that would suggest intelligent life is rare.
- adastra22 3y ago
  Symbiogenesis has occurred at least three separate times in the history of life on Earth. It is very unlikely to be a great filter.
  - _hypx_ 3y ago
    Twice, not three times. And the second in an organism that already achieved symbiogenesis. All of this took around 2 billion years or so to happen. It is a potential great filter candidate, but we only have a sample size of one. So if it turns out the above set of events is rare, then the prokaryote-eukaryote transition would be a major barrier to intelligent life.
    - adastra22 3y ago
      Three times. There is a very small, not extensively developed branch of life that has a separate primary symbiogebesis event (incorporating cyanobacteria) in the very recent evolutionary past, separate from mitochondria and chloroplasts: https://en.m.wikipedia.org/wiki/Paulinella https://en.m.wikipedia.org/wiki/Paulinella
      - _hypx_ 3y ago
        Which would be the third time in nearly 4 billion years. Still pretty unlikely. Both second and third examples are with an organism that already achieved the eukaryotic stage. It's still not clear if the original shift was a likely event.
prirun 3y ago
> ET with its own space capsule will not happen anytime soon. Or may have already ready been and gone billions of years ago.

ggm 3y ago

Some gases produced by simple organisms can also have non organic origins. So, ideally it would be complex chemistry to increase the likelihood it's not simpler origins. Finding simpler organism evidence would of course be huge but it would remain a single evidence basis for a long time I think. Finding more distinct complex products would help. Finding RF with a structural asymmetry implying information is the gold standard.

az09mugen 3y ago
What about dimethyl sulfide ? https://mashable.com/article/james-webb-space-telescope-exoplanet-discovery-1 https://mashable.com/article/james-webb-space-telescope-exop... EDIT : https://en.m.wikipedia.org/wiki/Dimethyl_sulfide https://en.m.wikipedia.org/wiki/Dimethyl_sulfide

nabla9 3y ago

Over 5,500 planets have been discovered. Once we see clear biosignature gas spectra, we get much better estimate for f_l parameter in Drake's equation (the number of active, communicative extraterrestrial civilizations in our galaxy) The current upper estimate is 10 million (set all unknown probability parameters in Drake's equation to 1.0 and L to infinite.) Setting unknown parameters to even slightly less optimistic numbers drops the estimate dramatically. For example: if you set life develops into intelligence = 0.5 , able to technologically communicate = 0.5, and lifetime = 100k years, you get N=30.