Comets that 'bounce' from planet to planet could spread life across the universe(space.com)
space.com
Comets that 'bounce' from planet to planet could spread life across the universe
https://www.space.com/comets-bouncing-seed-life-on-exoplanets
49 comments
Some user posted here about how thinking of Earth as the origin of life is the last remaining piece of geocentrism and I can't stop thinking about it.
Someone commented "what if life existed before the big bang", but deleted their comment.
I want to comment on that that Roger Penrose is considering the existence and possible detection of a universe before the big bang, something he also touched on in his Nobel lecture.
https://news.ycombinator.com/item?id=37621098
I want to comment on that that Roger Penrose is considering the existence and possible detection of a universe before the big bang, something he also touched on in his Nobel lecture.
https://news.ycombinator.com/item?id=37621098
His potential clues of CCC (the cyclic universe) in the CMB turned out to be incorrect.
So as of now, this theory is not supported by anything.
So as of now, this theory is not supported by anything.
Not much could survive the conditions, unless you're thinking of aliens with technological means and some kind of ability to translate themselves into quark gluon physics and back.
In our timeline, we still have billions if not trillions of years of potential technological life and -evolution ahead of us, until the last (dwarf) stars cease existing, if not longer through other means, so I wouldn't rule anything out.
Also, even if life did not causally begin in this universe through "external" influence like this, transmitted signals may potentially influence the future of life greatly nonetheless.
Also, even if life did not causally begin in this universe through "external" influence like this, transmitted signals may potentially influence the future of life greatly nonetheless.
Thanks for sharing! I'm personally a fan of the idea that life has always existed, meaning we have always existed as well. It's very cool to listen to someone like Roger Penrose expressing his thoughts on what possibly happened before the big bang. In my opinion, everything in Nature repeats, and nothing is so special that it cannot happen again when we understand the concept of infinity. People who favor the idea of believing in God might be against such a notion, but I think it's worth exploring along with all the philosophy that can emerge from it.
„Ewiges Leben - ein Verleugnen der ewigen Wiederkehr des Gleichen.“
―Friedrich Nietzsche
―Friedrich Nietzsche
I've been thinking recently (in part inspired by Penrose and other recursive universe theories): what if we can effect the trajectory of this current universe such that the next universe that is created has definable properties. As a highly improbable example I use only to spur imagination, what if we could control the next big bang so precisely that a solar system exactly like ours would exist containing humans just like us.
That would lead me to speculate that if we were looking for messages from the previous universe (in the style of the movie/book Contact) then we should look to the signature of the background radiation (CMB). Imagine a previous universe left us instructions there to help us achieve this, and perhaps therefore to achieve some objective that spans multiple universes (i.e. some objective too large to complete within the lifespan of a single universe).
If that isn't a sci-fi book then it should be. Also maybe an interesting area for legit academic study (e.g. how to imprint instructions in the CMB to pass along to future universes).
That would lead me to speculate that if we were looking for messages from the previous universe (in the style of the movie/book Contact) then we should look to the signature of the background radiation (CMB). Imagine a previous universe left us instructions there to help us achieve this, and perhaps therefore to achieve some objective that spans multiple universes (i.e. some objective too large to complete within the lifespan of a single universe).
If that isn't a sci-fi book then it should be. Also maybe an interesting area for legit academic study (e.g. how to imprint instructions in the CMB to pass along to future universes).
> That would lead me to speculate that if we were looking for messages from the previous universe (in the style of the movie/book Contact) then we should look to the signature of the background radiation (CMB).
That was the premise behind the Stargate Universe TV series.
<spoilers> The Ancients detect a pattern in the cosmic background radiation that hints at an intelligence that existed before the beginning of time and send a fleet of automated ships with FTL to research it. Millions of years later, the US Air Force manages to send a team on a one way trip to the flagship and hijinks ensue.</spoilers>
That was the premise behind the Stargate Universe TV series.
<spoilers> The Ancients detect a pattern in the cosmic background radiation that hints at an intelligence that existed before the beginning of time and send a fleet of automated ships with FTL to research it. Millions of years later, the US Air Force manages to send a team on a one way trip to the flagship and hijinks ensue.</spoilers>
More proof that there are no new ideas under the sun! It is interesting to me that they chose the CMB as well. Although, looking at the Wikipedia synopsis it seems to speculate: "This discovery suggested the possibility of life before or immediately after the Big Bang, and Destiny was launched millions of years ago to study and gather data regarding this possibility."
I wonder if they were going towards a purposeful communication plot as well, or even a plot suggesting a recurrence theme. I think of it sometimes like the ouroboros/eternal-return mystical philosophy. Like, the advanced life that we end up creating in this universe knows that the only way it can recreate itself is to recreate us, like we are just some kind of bootstrap for the universe's final form.
I wonder if they were going towards a purposeful communication plot as well, or even a plot suggesting a recurrence theme. I think of it sometimes like the ouroboros/eternal-return mystical philosophy. Like, the advanced life that we end up creating in this universe knows that the only way it can recreate itself is to recreate us, like we are just some kind of bootstrap for the universe's final form.
GPT4 is good at sketching out stories like this.
https://chat.openai.com/share/3143a927-a283-4abd-aae3-1f0542...
https://chat.openai.com/share/3143a927-a283-4abd-aae3-1f0542...
Not before the Big Bang, but this is interesting -- what if life developed when the entire universe was in the habitable zone?
https://www.youtube.com/watch?v=JOiGEI9pQBs
https://www.youtube.com/watch?v=JOiGEI9pQBs
Wasn’t that environment saturated by gamma rays? I’m thinking of the pre-redshift cosmic microwave background.
Now I won't be able to stop thinking about that too. It is an interesting way to frame that idea.
[deleted]
The naive hypothesis is that life originates in many places in the cosmos.
This article isn't postulating comets as spreading life, per se, but as spreading molecular pre-requisites for our sort of life.
This article isn't postulating comets as spreading life, per se, but as spreading molecular pre-requisites for our sort of life.
They weren't wrong, in an infinite universe, everywhere is the center.
I'm not sure it's necessarily geocentrism, so much as the most Occam's razor-y assumption to run with until we have evidence to the contrary. Assuming life originated here means we don't also have to think about how it got here if it happened somewhere else.
IMO one doesn't preclude the other. Our forebears would have used the same logic to assume that the Sun orbited around the Earth.
I know it's a very common meme about geocentrism, but heliocentric models which would be pretty familiar to us existed all the way back ~300 BC [1] and potentially were on par with Copernicus' work ~150BC [2].
The geocentric interpretation was largely forced due to religious dogma and not due to a belief that it was simpler. It's honestly crazy how close people 2000 years ago were to a more contemporary understanding of the universe and how all that became lost and suppressed for ~1500 years.
[1] https://en.wikipedia.org/wiki/Aristarchus_of_Samos?&useskin=...
[2] https://en.wikipedia.org/wiki/Seleucus_of_Seleucia?&useskin=...
The geocentric interpretation was largely forced due to religious dogma and not due to a belief that it was simpler. It's honestly crazy how close people 2000 years ago were to a more contemporary understanding of the universe and how all that became lost and suppressed for ~1500 years.
[1] https://en.wikipedia.org/wiki/Aristarchus_of_Samos?&useskin=...
[2] https://en.wikipedia.org/wiki/Seleucus_of_Seleucia?&useskin=...
That's a better idea than moderns give it credit for.
If Earth orbits around the sun, you'd expect we'd see the stars move, as Earth moves relative to them. You have to assume the stars are absurdly far away to make that model fit with observations.
Of course, now we know that stars are that far away, but I can't fault the Geocentrics of old for picking the more reasonable model.
If Earth orbits around the sun, you'd expect we'd see the stars move, as Earth moves relative to them. You have to assume the stars are absurdly far away to make that model fit with observations.
Of course, now we know that stars are that far away, but I can't fault the Geocentrics of old for picking the more reasonable model.
I don't see how that's an apt analogy. Geocentrism put the Earth at the center of the universe, around which the rest of the universe rotated. But saying life on Earth originated on Earth does not in any way put the Earth at the center of anything. Nor does it in any way mean that Earth is unique.
The bottom line is that -- because we don't know how abiogenesis occurred, whether here or somewhere else -- we have no way to judge how common it is. It could be that, given enough time, life spontaneously forms on any planet or moon that offers a certain set of conditions, and Earth just happens to be one of those planets, meaning it is still not "the center" of anything.
In fact, in the extreme case, panspermia is much more geocentric, saying that life formed in just one very special place -- maybe not the Earth, but somewhere, the "center of life in the universe" -- and then spread by diffusion to all the other locations in which life existed. But that seems like an unlikely and unnecessary model; if life can spontaneously begin somewhere, why should we assume it can't begin in many places, and if that's true, why not also on Earth?
The bottom line is that -- because we don't know how abiogenesis occurred, whether here or somewhere else -- we have no way to judge how common it is. It could be that, given enough time, life spontaneously forms on any planet or moon that offers a certain set of conditions, and Earth just happens to be one of those planets, meaning it is still not "the center" of anything.
In fact, in the extreme case, panspermia is much more geocentric, saying that life formed in just one very special place -- maybe not the Earth, but somewhere, the "center of life in the universe" -- and then spread by diffusion to all the other locations in which life existed. But that seems like an unlikely and unnecessary model; if life can spontaneously begin somewhere, why should we assume it can't begin in many places, and if that's true, why not also on Earth?
The idea is that it puts Earth at the center of the biological universe.
Generally the idea is that abiogenesis is very rare. I don't think any panspermists are saying that it only happened in one spot. As you pointed out that's basically the same belief as thinking it happened just once on Earth. The two 'versions' (they're not mutually exclusive) I'm familiar with are spreading via waterbears on comets or whatever, and also seeding by intelligent life. I think we have evidence for both in our own solar system, although the life we've seeded probably didn't take hold for very long.
Generally the idea is that abiogenesis is very rare. I don't think any panspermists are saying that it only happened in one spot. As you pointed out that's basically the same belief as thinking it happened just once on Earth. The two 'versions' (they're not mutually exclusive) I'm familiar with are spreading via waterbears on comets or whatever, and also seeding by intelligent life. I think we have evidence for both in our own solar system, although the life we've seeded probably didn't take hold for very long.
Scientifically the only life I can prove exists is on earth. We have found no evidence of life in any form anywhere. It’s totally reasonable to believe that may in fact be the case. The statement that it’s geocentrism makes the supposition that it’s ego that drives assumption of life only on earth. However if life only exists on earth, we would necessarily be the ones observing the empty universe.
A distinct possibility is that it takes a long time and very unique situations for life to evolve. The first life in the universe would look out at a lifeless universe. Life may later develop, and we are the first. Maybe life develops here first, and ejecta from our atmosphere seeding the space we travel through spreads it through the galaxy and the universe.
Maybe life existed everywhere during the Goldilocks period of the universe and has died out almost everywhere and we are the last ember.
But the only evidence we have for any of these theories - literally the only evidence - is that we are alone.
But I am glad we keep looking to prove that wrong.
A distinct possibility is that it takes a long time and very unique situations for life to evolve. The first life in the universe would look out at a lifeless universe. Life may later develop, and we are the first. Maybe life develops here first, and ejecta from our atmosphere seeding the space we travel through spreads it through the galaxy and the universe.
Maybe life existed everywhere during the Goldilocks period of the universe and has died out almost everywhere and we are the last ember.
But the only evidence we have for any of these theories - literally the only evidence - is that we are alone.
But I am glad we keep looking to prove that wrong.
Just a few decades ago it was absolutely correct to state that:
Today, of course, we are over run with evidence for exo planets.
Scientifically the only planets I can prove exists are here in this solar system. We have found no evidence of planets anywhere else.
Today, of course, we are over run with evidence for exo planets.
There is a pretty significant gap in the implications of the existence of exoplanets and in the implications of the existence of exobiology.
Prior to the detection of exoplanets, there was likely still a general consensus that they probably exist, because that didn't really have any implications for our model of the universe. It was understandable that the technology of the time was just not capable of detecting things that small.
The question of life becomes more complicated because what it means in terms of detectability is completely different depending on the conditions. Depending on how common it is, things range from it being weird we haven't detected any yet to it being so rare that our existence is indeed special.
Prior to the detection of exoplanets, there was likely still a general consensus that they probably exist, because that didn't really have any implications for our model of the universe. It was understandable that the technology of the time was just not capable of detecting things that small.
The question of life becomes more complicated because what it means in terms of detectability is completely different depending on the conditions. Depending on how common it is, things range from it being weird we haven't detected any yet to it being so rare that our existence is indeed special.
> to it being so rare that our existence is indeed special.
Which is possible but hardly reasonable . . .
Many in STEM would argue that it's reasonable to assume we're not at all special.
Which is possible but hardly reasonable . . .
Many in STEM would argue that it's reasonable to assume we're not at all special.
Life may not be "special", but we (our lineage) has gone through a few demonstrably evolutionarily rare events to get to the point we are.
The question is whether there is life elsewhere, not whether we have replicants "out there".
That said, the entire universe as is appears to be in incredibly rare event, moreso than mere evolution.
That said, the entire universe as is appears to be in incredibly rare event, moreso than mere evolution.
I kind of meant "we" as "intelligent life" capable of astronomical science.
We have no idea how rare the universe is because we can't compare it to anything. We can compare terrestrial species to all of the other terrestrial species we know of. This shows that some evolutionary trajectories and forms appear to be more or less frequent outcomes.
We have no idea how rare the universe is because we can't compare it to anything. We can compare terrestrial species to all of the other terrestrial species we know of. This shows that some evolutionary trajectories and forms appear to be more or less frequent outcomes.
> We have no idea how rare the universe is because we can't compare it to anything.
Good luck floating that past your typical theoretical astrophysicist, there are several quite different approaches to taking a stab at that one - all fall into can't be resolved either way basket though, I see your point.
fnordpiglet mentions the rare earth notion, I first came across that in the mid 70's reading an Asimov non fiction essay collection The Tragedy of the Moon which raised the importance(??) of having a moon to create tides to create intertidal zones to nudge life from water to land.
https://en.wikipedia.org/wiki/The_Tragedy_of_the_Moon
There's a long chain of chance that lies behind ourselves arriving where we are ... the argument can still be made (as it was by Douglas Adams) that "The universe is big. Really Big."
The latest JWT images convey just a smidgeon of how big with high res images of tiny arc areas of the night sky packed with tiny lights that are each galaxies the size of the milky way and more.
That's a lot of rolls of the dice out there.
Good luck floating that past your typical theoretical astrophysicist, there are several quite different approaches to taking a stab at that one - all fall into can't be resolved either way basket though, I see your point.
fnordpiglet mentions the rare earth notion, I first came across that in the mid 70's reading an Asimov non fiction essay collection The Tragedy of the Moon which raised the importance(??) of having a moon to create tides to create intertidal zones to nudge life from water to land.
https://en.wikipedia.org/wiki/The_Tragedy_of_the_Moon
There's a long chain of chance that lies behind ourselves arriving where we are ... the argument can still be made (as it was by Douglas Adams) that "The universe is big. Really Big."
The latest JWT images convey just a smidgeon of how big with high res images of tiny arc areas of the night sky packed with tiny lights that are each galaxies the size of the milky way and more.
That's a lot of rolls of the dice out there.
The space is big, but time is vast too. There was a time in the universe when the entire universe averaged a temperature conducive to life and there was oxygen, carbon, and other crucial elements available (although not as plentiful as now). Life could have formed then, and largely died out. In fact life may only pop up rarely in both space and time, so rarely that it’s unlikely two planets have life within a detectable distance at the same time. In fact it’s even possible a highly advanced civilization formed on the earth many millions of years ago, and at those time scales all detectable traces of its existence would be wiped out. The scales of time and space are so vast we fail to comprehend how infinitesimal our scales are and make huge assumptions about what’s plausible based on our scales projected to universal scales. That’s geocentric!
Also, possible doesn’t mean plausible. Objects can teleport to the moon through quantum principles it’s just so unlikely it’s never actually happens in reality. Life may be such a vastly implausible thing that our existence is a miracle so improbable it beggars the imagination.
Also, possible doesn’t mean plausible. Objects can teleport to the moon through quantum principles it’s just so unlikely it’s never actually happens in reality. Life may be such a vastly implausible thing that our existence is a miracle so improbable it beggars the imagination.
In the universe we inhabit, what does rare mean? I think we think it is rare but we have no concept of the scale of the possible interactions.
That's the entire point of the fermi paradox.
The reasonable assumption as with most things is that we aren't special, yet the data increasingly does not appear to reflect that. Unlike with detecting exoplanets, blaming our sensors only makes this discrepancy worse.
Unless you're trying to make the argument that we haven't found life because we're looking for specifically Earth-like life, in which case I'd just say that it's more rational with our current technology to focus on the kind of life we definitely know can exist rather than hypothetical biochemstries we can't realistically test. It isn't even as if the conditions we're setting are especially extreme, a planet in a goldilocks zone of a relatively stable star with an atmosphere and signatures of water and potentially significant amounts of oxygen.
The reasonable assumption as with most things is that we aren't special, yet the data increasingly does not appear to reflect that. Unlike with detecting exoplanets, blaming our sensors only makes this discrepancy worse.
Unless you're trying to make the argument that we haven't found life because we're looking for specifically Earth-like life, in which case I'd just say that it's more rational with our current technology to focus on the kind of life we definitely know can exist rather than hypothetical biochemstries we can't realistically test. It isn't even as if the conditions we're setting are especially extreme, a planet in a goldilocks zone of a relatively stable star with an atmosphere and signatures of water and potentially significant amounts of oxygen.
The Fermi paradox assumes detection | communication is desirable | possible | recognisable by us.
It relates to intelligent lifeforms that show themselves in ways we can recognise.
It has little bearing on the question of life elsewhere - a starfish orbiting an exoplanet counts here.
Fermi was a little naive on the "space is big | communication is hard" front - before the James Cook expeditions life existed in Australia and yet the British monarchy hadn't received a single missive by Royal Mail from any of the numerous nations within Australia.
The methods of signalling long distances that we're aware of require focus and|or vast amounts of power and extremely long travel times; focus requires us to be targetted over a staggeringly large number of other solar systems, weilding vast amounts of power requires tech able to do so and not find other more efficient means, etc.
Those communicating across galaxies are doing so in ways we do not yet recognise, those with civilisations that cause their own suns to give them away are yet to be found as we have barely starting looking at a fraction of all the systems there are out there - JWT is good but it's barely been up a day in cosmic terms and there's much left to look at.
It relates to intelligent lifeforms that show themselves in ways we can recognise.
It has little bearing on the question of life elsewhere - a starfish orbiting an exoplanet counts here.
Fermi was a little naive on the "space is big | communication is hard" front - before the James Cook expeditions life existed in Australia and yet the British monarchy hadn't received a single missive by Royal Mail from any of the numerous nations within Australia.
The methods of signalling long distances that we're aware of require focus and|or vast amounts of power and extremely long travel times; focus requires us to be targetted over a staggeringly large number of other solar systems, weilding vast amounts of power requires tech able to do so and not find other more efficient means, etc.
Those communicating across galaxies are doing so in ways we do not yet recognise, those with civilisations that cause their own suns to give them away are yet to be found as we have barely starting looking at a fraction of all the systems there are out there - JWT is good but it's barely been up a day in cosmic terms and there's much left to look at.
The Fermi paradox isn’t what I would point to. It makes a lot of assumptions.
The rare earth hypothesis is much more rooted in first principles. The earth has a very rare combination of factors all of which are crucial to life as we know it, and likely anything we could recognize as life due to the factors life requires for maintaining its complexity and ability to self replicate and perpetuate. These are not limited to the specific nature of carbon, water, and oxygen in the Goldilocks zones, the necessity of a magnetosphere, in a very specific galactic structure in a specific part of such a galactic structure, making the specific envelope of Sol and earth with its unique tectonic geology, etc, all of which are literally necessary to evolve life. Other forms of life are theorized (silicon based, etc) but they have almost impossible requirements to assemble into structures complex enough with enough flow of energy without so much energy they fall apart. Every theorized xenobiology other than the one we have is likely impossible for pretty fundamental reasons. This doesn’t mean we have exhausted all possibilities or that nature won’t surprise us in crazy ways beyond our imagination, it just means life is almost certainly MUCH MUCH more rare than drakes equation lets on.
https://en.m.wikipedia.org/wiki/Rare_Earth_hypothesis
Again, I’m not saying life doesn’t exist outside earth. I’m saying we don’t know and despite really hard efforts to approach extraterrestrial life from every possible angle has been fruitless so far, even to the point we have no theories of life’s origins, how to detect life, and no open avenues that have any hope of such a discovery. At the moment it’s feeling less likely we will discover life outside the earth before we can reverse time (as we have done in simple time crystals). That should be daunting to our blind faith.
To my mind this should weigh on us as a burden. As long as we believe life exists elsewhere the loss of life on earth is sad, but ultimately inconsequential. If we are the seed of life in the practically observable universe, then we are the shepherd of the most amazing thing in all of creation. We have a responsibility to tend it, and IMO, spread it as far and wide as we can such that the universe does team with life and for the rest of all time life never feels alone.
The rare earth hypothesis is much more rooted in first principles. The earth has a very rare combination of factors all of which are crucial to life as we know it, and likely anything we could recognize as life due to the factors life requires for maintaining its complexity and ability to self replicate and perpetuate. These are not limited to the specific nature of carbon, water, and oxygen in the Goldilocks zones, the necessity of a magnetosphere, in a very specific galactic structure in a specific part of such a galactic structure, making the specific envelope of Sol and earth with its unique tectonic geology, etc, all of which are literally necessary to evolve life. Other forms of life are theorized (silicon based, etc) but they have almost impossible requirements to assemble into structures complex enough with enough flow of energy without so much energy they fall apart. Every theorized xenobiology other than the one we have is likely impossible for pretty fundamental reasons. This doesn’t mean we have exhausted all possibilities or that nature won’t surprise us in crazy ways beyond our imagination, it just means life is almost certainly MUCH MUCH more rare than drakes equation lets on.
https://en.m.wikipedia.org/wiki/Rare_Earth_hypothesis
Again, I’m not saying life doesn’t exist outside earth. I’m saying we don’t know and despite really hard efforts to approach extraterrestrial life from every possible angle has been fruitless so far, even to the point we have no theories of life’s origins, how to detect life, and no open avenues that have any hope of such a discovery. At the moment it’s feeling less likely we will discover life outside the earth before we can reverse time (as we have done in simple time crystals). That should be daunting to our blind faith.
To my mind this should weigh on us as a burden. As long as we believe life exists elsewhere the loss of life on earth is sad, but ultimately inconsequential. If we are the seed of life in the practically observable universe, then we are the shepherd of the most amazing thing in all of creation. We have a responsibility to tend it, and IMO, spread it as far and wide as we can such that the universe does team with life and for the rest of all time life never feels alone.
Yet that proves nothing. I’d point out that the fact there are multiple planets around our own star and the theory of how the universe evolved predicted planets around other stars with near certainty, and we even had an idea of how to detect them it was just a matter of a sensitive enough instrument and computational techniques.
We have nothing equivalent for life. But not for trying, we absolutely have, quite a lot with many techniques. But yet, nothing. We don’t even have a theory for how life emerges that’s very advanced or verifiable.
I’m not saying we are alone. But the fact we exist doesn’t prove other life exists, and it doesn’t mean life is plentiful. If there were one person left on earth, they would observe a planet and assume there must be more people because how could they possibly be alone? Yet, by construction, they are. That incredulity doesn’t change anything.
I’m not asserting we are alone, and I believe we aren’t. But just pointing out our belief proves absolutely nothing, and holding the opposite belief doesn’t mean egotism. It’s actually the most rational belief given all evidence that we are alone.
We have nothing equivalent for life. But not for trying, we absolutely have, quite a lot with many techniques. But yet, nothing. We don’t even have a theory for how life emerges that’s very advanced or verifiable.
I’m not saying we are alone. But the fact we exist doesn’t prove other life exists, and it doesn’t mean life is plentiful. If there were one person left on earth, they would observe a planet and assume there must be more people because how could they possibly be alone? Yet, by construction, they are. That incredulity doesn’t change anything.
I’m not asserting we are alone, and I believe we aren’t. But just pointing out our belief proves absolutely nothing, and holding the opposite belief doesn’t mean egotism. It’s actually the most rational belief given all evidence that we are alone.
Might have been me. I’ve said that for years. I doubt I’m the first though.
I thought of that after seeing this:
https://phys.org/news/2013-04-law-life-began-earth.html
Doesn’t prove anything but fascinating.
Maybe life began early in the universe and is everywhere, but only in some environments has it been able to achieve high levels of complexity.
This is ultimately testable. If this is true we should find life in the subsurface oceans of moons, some comets, etc. and it should be at least somewhat biochemically similar or show other evidence of very ancient common descent.
If it’s false then ET life should be very alien with no evidence of common descent and also probably very rare. Rarity is likely because this would suggest that abiogenesis must hop up a very high complexity cliff, which is a highly improbable event.
I thought of that after seeing this:
https://phys.org/news/2013-04-law-life-began-earth.html
Doesn’t prove anything but fascinating.
Maybe life began early in the universe and is everywhere, but only in some environments has it been able to achieve high levels of complexity.
This is ultimately testable. If this is true we should find life in the subsurface oceans of moons, some comets, etc. and it should be at least somewhat biochemically similar or show other evidence of very ancient common descent.
If it’s false then ET life should be very alien with no evidence of common descent and also probably very rare. Rarity is likely because this would suggest that abiogenesis must hop up a very high complexity cliff, which is a highly improbable event.
Life on earth is so specifically bound to Earth's conditions, I don't understand how anybody could really say this.
I've no doubt there's things like life in other places. I have no reason to assume they'll be that strictly similar what we call life here, and we may not even recognize them as such. To imagine they are similar to earth-life to me seems more anthropo/geocentric.
Arguably our obsession with looking for stuff similar to us is perhaps blinding us to the true diversity in the cosmos.
I've no doubt there's things like life in other places. I have no reason to assume they'll be that strictly similar what we call life here, and we may not even recognize them as such. To imagine they are similar to earth-life to me seems more anthropo/geocentric.
Arguably our obsession with looking for stuff similar to us is perhaps blinding us to the true diversity in the cosmos.
Multi-cellular life, sure. But single cell life is hardier and could survive lots of places.
And we're blind to the cosmos, period. All we can see is star-sized objects and bigger. No one is ruling out other possibilities, they're just thinking about where we can look first, when we start looking.
And we're blind to the cosmos, period. All we can see is star-sized objects and bigger. No one is ruling out other possibilities, they're just thinking about where we can look first, when we start looking.
Multicellular life in the oceans would be bound more to the conditions of an ocean than of the non-marine Earth. And while there's some diversity in oceans, much of this diversity would be captured in any given ocean.
Multicellular life tried a whole bunch of shapes and niches early on. It would be interesting if some of the also-rans in Earth's oceans became the winners in other oceans.
Multicellular life tried a whole bunch of shapes and niches early on. It would be interesting if some of the also-rans in Earth's oceans became the winners in other oceans.
Live has persisted on Earth through several large changes in temperature and the gas composition of the atmosphere - many of those changes caused by life itself.
I'd expect life elsewhere to be much like ours in general, especially when you consider the full range of life both present and past on earth. The course of evolution is necessarily going to be similar anywhere - bound by the rules of chemistry, going from simple to complex forms, single cellular to multicellular, a full range of sensory modalities developing, predator/prey species evolving under similar high level dynamics, etc, etc. These types of generality have nothing to do specifically with life on earth.
Of course the details will vary, but I'd expect alien animals to be recognizably animals, even if they include some novel aspects specific to their own environments.
Of course the details will vary, but I'd expect alien animals to be recognizably animals, even if they include some novel aspects specific to their own environments.
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The theory is often called "Panspermia"[1], which I've always thought was an interesting and evocative name for it; especially when it comes to these theoretical life-giving comets.
[1]https://en.wikipedia.org/wiki/Panspermia
[1]https://en.wikipedia.org/wiki/Panspermia
Are amino acids not present in rocky planet oceans?
I doubt we've found that yet, but probably safe to assume they are. And it's not being suggested that the comets create the life or amino acids in the first place; likely they have picked it up after being ejected from a rockey planet with an ocean during a large collision or something.
This title is click-bait. It sounds like it's talking about comets picking up life from one planet and delivering it to another, but that's not what the article (and paper) says. They're just talking about space-generated biomolecules being delivered to planets (as has been found on Earth); the only "bouncing" involved is a comet losing energy by going through gravity wells in a dense planetary system.
We should be delivering packets of extremophiles to every body in the solar system, and see if anything takes hold.