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I can't help but keep wondering if "life originated on Earth" might not be the last geocentrism. It's only speculation at this point but it's one I've harbored

by api 9y ago

I can't help but keep wondering if "life originated on Earth" might not be the last geocentrism. It's only speculation at this point but it's one I've harbored for many years. Part of this is because of how common we've found organic materials to be in the universe, and part of it comes from how poorly other geocentric ideas have fared.

carapace 9y ago
I'd love for this story to be true but it's almost certainly not, the bacteria must be terrestrial. Cf. https://en.wikipedia.org/wiki/Tersicoccus_phoenicis https://en.wikipedia.org/wiki/Tersicoccus_phoenicis "It has only been found in two spacecraft assembly clean room facilities..." Maybe it's not T. phoenicis but it's not ET. (However, if it somehow turns out to be alien, that seems to be to imply that interstellar space must be swarming with bacteria, yes? For the ISS to have encountered some already?)
- api 9y ago
  You're probably right in this case, but as for the last part consider that the Earth is a gravity well and the ISS has been in space for a very long time. Earth is going to draw in particles and the ISS has had plenty of time to catch them.
  - sitkack 9y ago
    Then shouldn't the Earth Moon Lagrange points have bacteria in them them as well? Or Geosync satellites? Plenty of places to look.
TheAdamAndChe 9y ago
Sure, but we aren't holding to this form of biological geocentrism for no reason. We've never seen any definite proof of life on any other planets. Given that science is an evidence-based methodology, it makes sense that we would assume Earth-based life is the only model of life until proven otherwise.
- jackmott 9y ago
  if we wanted to be perfect logicians we would assume neither but believe the geocentric case to be a likely possibility.
  - TheAdamAndChe 9y ago
    If we want to be perfect logicians, then there is no reality or absolute truth in anything, but that's just a bit pedantic IMO ;) Conclusions at some point need to be made to progress.
  - mikeash 9y ago
    Wanting to be perfect logicians is an oxymoron, as there is no perfectly logical reason to want to be one!
  - triangleman 9y ago
    Hi jackmott FYI you are "hellbanned" which means nobody can see your comments. I'm sorry to be the bearer of bad news. The mods on this site are overly strict and quick to employ such a harsh tactic, IMO.
- tgb 9y ago
  It's worth noting that geocentrism wasn't held onto for no reason either. At least the ancient Greeks had solid logical reasons for believing it: if the Earth orbited the sun, then there would be parallax visible between the stars since the Earth's position among the stars is changing throughout the year. Yet, there is none. Therefore the Earth is fixed in space. The error of course is that the stars are really unimaginably far away and hence there is parallax but it's practically indiscernible. The Greeks thought the stars being that far away was the less likely answer to the apparent lack of parallax than the Earth simply being the center of the solar system.
lancebeet 9y ago
This theory is called panspermia for those who are interested. https://en.wikipedia.org/wiki/Panspermia https://en.wikipedia.org/wiki/Panspermia
reubenswartz 9y ago
There are plausible theories about how life arose on Earth. If you want to assume it came from somewhere else, you either have to invoke some kind of magic, or assume it happened somewhat along the lines that it would have done on Earth, then arrived somehow. It just kicks the can down the road without solving anything, IMO.
- swift 9y ago
  The hypothesis that life on Earth originated elsewhere is somewhat independent of abiogenesis, really. At least in my experience, most supporters of the former also support the latter.
- avian 9y ago
  > It just kicks the can down the road without solving anything Panspermia is an attempt to explain one inconsistency in our observations so far: it appears that life spontaneously emerging from inorganics is hugely unlikely. On other hand, geological records show that life appeared on Earth very soon after it became viable. If life on Earth originated somewhere else, then this discrepancy can be made to disappear. For example, abiogenesis only needs to arise once within a large radius around Earth and within a much broader time margin. Hence it can be a very rare event while still not making early life on Earth a unique event in the universe. I don't personally believe panspermia is likely. But it is a valid theory (although without much supporting evidence as far as I know).
  - reubenswartz 9y ago
    It's certainly a valid hypothesis. And stronger (any?) evidence for possible life on Mars or Venus would possibly support this. With a sample size of 1, and loose record-keeping from ~4B years ago, it's hard to tell, but we don't really know if it took life 1 day or 500M years to evolve once it was chemically/geologically viable. We do know that life was very primitive for > 1B years (not even eukaryotic, let alone multicellular). We also know that space isn't teaming with little biologically active spores from other worlds (unless it is and the government is covering it up, of course), which suggests that in the vastness of space, life doesn't really hitch rides on asteroids or comets and colonize the galaxy accidentally. And if some beings were doing this on purpose, why not send more advanced life forms or robots?

by api 9y ago

carapace 9y ago

I'd love for this story to be true but it's almost certainly not, the bacteria must be terrestrial. Cf. https://en.wikipedia.org/wiki/Tersicoccus_phoenicis https://en.wikipedia.org/wiki/Tersicoccus_phoenicis "It has only been found in two spacecraft assembly clean room facilities..." Maybe it's not T. phoenicis but it's not ET. (However, if it somehow turns out to be alien, that seems to be to imply that interstellar space must be swarming with bacteria, yes? For the ISS to have encountered some already?)

api 9y ago
You're probably right in this case, but as for the last part consider that the Earth is a gravity well and the ISS has been in space for a very long time. Earth is going to draw in particles and the ISS has had plenty of time to catch them.
- sitkack 9y ago
  Then shouldn't the Earth Moon Lagrange points have bacteria in them them as well? Or Geosync satellites? Plenty of places to look.

TheAdamAndChe 9y ago

Sure, but we aren't holding to this form of biological geocentrism for no reason. We've never seen any definite proof of life on any other planets. Given that science is an evidence-based methodology, it makes sense that we would assume Earth-based life is the only model of life until proven otherwise.

jackmott 9y ago
if we wanted to be perfect logicians we would assume neither but believe the geocentric case to be a likely possibility.
- TheAdamAndChe 9y ago
  If we want to be perfect logicians, then there is no reality or absolute truth in anything, but that's just a bit pedantic IMO ;) Conclusions at some point need to be made to progress.
- mikeash 9y ago
  Wanting to be perfect logicians is an oxymoron, as there is no perfectly logical reason to want to be one!
- triangleman 9y ago
  Hi jackmott FYI you are "hellbanned" which means nobody can see your comments. I'm sorry to be the bearer of bad news. The mods on this site are overly strict and quick to employ such a harsh tactic, IMO.
tgb 9y ago
It's worth noting that geocentrism wasn't held onto for no reason either. At least the ancient Greeks had solid logical reasons for believing it: if the Earth orbited the sun, then there would be parallax visible between the stars since the Earth's position among the stars is changing throughout the year. Yet, there is none. Therefore the Earth is fixed in space. The error of course is that the stars are really unimaginably far away and hence there is parallax but it's practically indiscernible. The Greeks thought the stars being that far away was the less likely answer to the apparent lack of parallax than the Earth simply being the center of the solar system.

lancebeet 9y ago

This theory is called panspermia for those who are interested. https://en.wikipedia.org/wiki/Panspermia https://en.wikipedia.org/wiki/Panspermia

reubenswartz 9y ago

There are plausible theories about how life arose on Earth. If you want to assume it came from somewhere else, you either have to invoke some kind of magic, or assume it happened somewhat along the lines that it would have done on Earth, then arrived somehow. It just kicks the can down the road without solving anything, IMO.

swift 9y ago
The hypothesis that life on Earth originated elsewhere is somewhat independent of abiogenesis, really. At least in my experience, most supporters of the former also support the latter.
avian 9y ago
> It just kicks the can down the road without solving anything Panspermia is an attempt to explain one inconsistency in our observations so far: it appears that life spontaneously emerging from inorganics is hugely unlikely. On other hand, geological records show that life appeared on Earth very soon after it became viable. If life on Earth originated somewhere else, then this discrepancy can be made to disappear. For example, abiogenesis only needs to arise once within a large radius around Earth and within a much broader time margin. Hence it can be a very rare event while still not making early life on Earth a unique event in the universe. I don't personally believe panspermia is likely. But it is a valid theory (although without much supporting evidence as far as I know).
- reubenswartz 9y ago
  It's certainly a valid hypothesis. And stronger (any?) evidence for possible life on Mars or Venus would possibly support this. With a sample size of 1, and loose record-keeping from ~4B years ago, it's hard to tell, but we don't really know if it took life 1 day or 500M years to evolve once it was chemically/geologically viable. We do know that life was very primitive for > 1B years (not even eukaryotic, let alone multicellular). We also know that space isn't teaming with little biologically active spores from other worlds (unless it is and the government is covering it up, of course), which suggests that in the vastness of space, life doesn't really hitch rides on asteroids or comets and colonize the galaxy accidentally. And if some beings were doing this on purpose, why not send more advanced life forms or robots?