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Would you mind elaborating on this? I don’t understand the point. Maybe naively, I would think that evidence of life on mars would increase the probability of l

by 5tk18 1y ago

Would you mind elaborating on this? I don’t understand the point. Maybe naively, I would think that evidence of life on mars would increase the probability of life on exoplanets.

xg15 1y ago
I guess the question is: If there was life on mars, what happened to it?
- maxbond 1y ago
  Presumably the planet became much less geologically active, causing Mars to lose it's magnetic field and thus it's atmosphere, and that caused a mass extinction. If there was life on the surface in the past, I imagine it still exists deep underground or in lava tubes or such.
- rrmm 1y ago
  I think the building blocks of life are so common in the universe it might be a case of "easy come, easy go". It wouldn't be surprising if simple life happened anywhere it was given half a chance at all, but one would equally expect that it would die out just as quickly when conditions changed (which they certainly did on Mars). And of course nothing is ruling out life in the nooks and crannies of Mars.
- empath75 1y ago
  That actually isn't a hard question to answer. Mars lacks an active core or a magnetosphere, so the atmosphere blew away, freezing the surface and removing almost all of the liquid water.
- estimator7292 1y ago
  We have proven that Mars used to have a magnetic field like Earth that protected it from solar radiation. We also know that it does not presently have a magnetic field. At some point in the distant past, Mars's core cooled and solidified, which removes the magnetic field. The big problem is that the solar wind strips away the atmosphere and water, but that's (probably) not what killed all Martian life. As the magnetic field decreases, more and more harmful radiation reaches the surface. The planet was probably sterilized by radiation long before the atmosphere was lost and the oceans evaporated. We're pretty sure this is what happened. We've been studying Mars's geology for a long time and we can see evidence for most of this process.
- Qem 1y ago
  Likely, when Mars went bad, their planet B was Earth. Nowadays they call themselves Earthlings (AKA us).
- tim333 1y ago
  It may still be there doing it's thing, mostly underground. The surface of Mars is currently very dry for any life we know but there seems to be water underground https://www.bbc.co.uk/news/science-environment-54337779 https://www.bbc.co.uk/news/science-environment-54337779
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withinboredom 1y ago
We’re working off the assumption that life is rare in the universe (and thus a great filter). That is why the stars aren’t covered in life. If this isn’t true, and life is actually common throughout the galaxy ... then the great filter might still be ahead of us — such as not surviving technological adolescence. Meaning we’re not special, we just haven’t died off yet.
- JumpCrisscross 1y ago
  > assumption that life is rare in the universe Great filters start with the observation that we have detected no signs of alien technological civilization. The assumption is this means they’re rare.
  - harshalizee 1y ago
    Or just really hard to detect with existing technology. Combine that with the vastness of the universe, it's not a unreasonable take.
  - withinboredom 1y ago
    That doesn’t mean much. If it is actually common and the great filter is passing technological adolescence, then at least one civilisation would need to be around at least a hundred thousand years ago to be detected by us. Then, they would need to survive the great filter. We’ve only been broadcasting for 80 years or so, and any modern technology is probably indistinguishable from noise... In other words, even if the average technological civilisation lasts 1000 years, the odds of those civilisations overlapping are nearly zero if the great filter is ahead of us. Unless civilisations manage to last much, much longer than 1,000 years (millions of years), the chance that two blips overlap in time and space closely enough to detect each other is basically negligible. That is why the “life on Mars” point feels ominous: - If abiogenesis is easy, the filter isn’t there. - If the filter is later (like surviving technological adolescence), then most civilisations blink out quickly. Which means overlapping, detectable civilisations would be vanishingly rare, explaining the silence, but also suggesting our future may be short.
nwah1 1y ago
If the solution to the Fermi Paradox is that there's a great filter that prevents many advanced civilizations from sticking around long enough to be observable, then we hope that the filter is behind us rather than in front of us. The more common that life is, the more likely it is in front of us. https://en.wikipedia.org/wiki/Great_Filter https://en.wikipedia.org/wiki/Great_Filter
- kjkjadksj 1y ago
  The elephant in the room here is that advanced intelligent life as we understand it is some inevitable step in evolution. A random walk of mutations on top of mutations lead us to this and only because the environmental context favored adaptions toward intelligence in the case of our species at the time. This is probably why most sci fi is not written by evolutionary biologists.
  - soiltype 1y ago
    Er... No that's not a meaningful critique. There's no framework that doesn't assume it's a random process. The point is to find out how likely each step is to occur, randomly.
    - kjkjadksj 1y ago
      Even the Kardashev scale is based on the assumption that unfettered economic activity as humans conceived of it in the mid 20th century would be a common enough phenomenon to classify, including shoehorning in our wildest science fiction ideas. Only the most unscrupulous of our species probably want to maximize production of widgets beyond the limits of this planet to the point where a Dyson sphere must be built. Would a Buddhist monk have any interest in that for example, or are their metrics of “productivity” more metaphysical perhaps? Or someone considering preserving a system and not exceeding what it is capable of sustainably offering? How about a blue whale, do they have an increasing energy demand per capita as well?
      - soiltype 1y ago
deleted 1y ago
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by 5tk18 1y ago

Would you mind elaborating on this? I don’t understand the point. Maybe naively, I would think that evidence of life on mars would increase the probability of life on exoplanets.

xg15 1y ago

I guess the question is: If there was life on mars, what happened to it?

maxbond 1y ago
Presumably the planet became much less geologically active, causing Mars to lose it's magnetic field and thus it's atmosphere, and that caused a mass extinction. If there was life on the surface in the past, I imagine it still exists deep underground or in lava tubes or such.
rrmm 1y ago
I think the building blocks of life are so common in the universe it might be a case of "easy come, easy go". It wouldn't be surprising if simple life happened anywhere it was given half a chance at all, but one would equally expect that it would die out just as quickly when conditions changed (which they certainly did on Mars). And of course nothing is ruling out life in the nooks and crannies of Mars.
empath75 1y ago
That actually isn't a hard question to answer. Mars lacks an active core or a magnetosphere, so the atmosphere blew away, freezing the surface and removing almost all of the liquid water.
estimator7292 1y ago
We have proven that Mars used to have a magnetic field like Earth that protected it from solar radiation. We also know that it does not presently have a magnetic field. At some point in the distant past, Mars's core cooled and solidified, which removes the magnetic field. The big problem is that the solar wind strips away the atmosphere and water, but that's (probably) not what killed all Martian life. As the magnetic field decreases, more and more harmful radiation reaches the surface. The planet was probably sterilized by radiation long before the atmosphere was lost and the oceans evaporated. We're pretty sure this is what happened. We've been studying Mars's geology for a long time and we can see evidence for most of this process.
Qem 1y ago
Likely, when Mars went bad, their planet B was Earth. Nowadays they call themselves Earthlings (AKA us).
tim333 1y ago
It may still be there doing it's thing, mostly underground. The surface of Mars is currently very dry for any life we know but there seems to be water underground https://www.bbc.co.uk/news/science-environment-54337779 https://www.bbc.co.uk/news/science-environment-54337779

deleted 1y ago

[deleted]

withinboredom 1y ago

We’re working off the assumption that life is rare in the universe (and thus a great filter). That is why the stars aren’t covered in life. If this isn’t true, and life is actually common throughout the galaxy ... then the great filter might still be ahead of us — such as not surviving technological adolescence. Meaning we’re not special, we just haven’t died off yet.

JumpCrisscross 1y ago
> assumption that life is rare in the universe Great filters start with the observation that we have detected no signs of alien technological civilization. The assumption is this means they’re rare.
- harshalizee 1y ago
  Or just really hard to detect with existing technology. Combine that with the vastness of the universe, it's not a unreasonable take.
- withinboredom 1y ago
  That doesn’t mean much. If it is actually common and the great filter is passing technological adolescence, then at least one civilisation would need to be around at least a hundred thousand years ago to be detected by us. Then, they would need to survive the great filter. We’ve only been broadcasting for 80 years or so, and any modern technology is probably indistinguishable from noise... In other words, even if the average technological civilisation lasts 1000 years, the odds of those civilisations overlapping are nearly zero if the great filter is ahead of us. Unless civilisations manage to last much, much longer than 1,000 years (millions of years), the chance that two blips overlap in time and space closely enough to detect each other is basically negligible. That is why the “life on Mars” point feels ominous: - If abiogenesis is easy, the filter isn’t there. - If the filter is later (like surviving technological adolescence), then most civilisations blink out quickly. Which means overlapping, detectable civilisations would be vanishingly rare, explaining the silence, but also suggesting our future may be short.

nwah1 1y ago

If the solution to the Fermi Paradox is that there's a great filter that prevents many advanced civilizations from sticking around long enough to be observable, then we hope that the filter is behind us rather than in front of us. The more common that life is, the more likely it is in front of us. https://en.wikipedia.org/wiki/Great_Filter https://en.wikipedia.org/wiki/Great_Filter

kjkjadksj 1y ago
The elephant in the room here is that advanced intelligent life as we understand it is some inevitable step in evolution. A random walk of mutations on top of mutations lead us to this and only because the environmental context favored adaptions toward intelligence in the case of our species at the time. This is probably why most sci fi is not written by evolutionary biologists.
- soiltype 1y ago
  Er... No that's not a meaningful critique. There's no framework that doesn't assume it's a random process. The point is to find out how likely each step is to occur, randomly.
  - kjkjadksj 1y ago
    Even the Kardashev scale is based on the assumption that unfettered economic activity as humans conceived of it in the mid 20th century would be a common enough phenomenon to classify, including shoehorning in our wildest science fiction ideas. Only the most unscrupulous of our species probably want to maximize production of widgets beyond the limits of this planet to the point where a Dyson sphere must be built. Would a Buddhist monk have any interest in that for example, or are their metrics of “productivity” more metaphysical perhaps? Or someone considering preserving a system and not exceeding what it is capable of sustainably offering? How about a blue whale, do they have an increasing energy demand per capita as well?
    - soiltype 1y ago

deleted 1y ago

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