If you recall, our grabby aliens analysis tries to explain 3 key datums: a) we don’t see any huge alien civs in our sky b) we have arrived at a very early date in the universe, and c) there is only ~1Gyr left for life on Earth.
Very interesting ideas here. Kipping's hypothesis of "a crazy small chance that intelligence like ours gives rise to a distantly-visible civilization" doesn't necessarily imply a great filter in our future. It could be that most intelligent life wants to advance in a direction that isn't distantly visible. For example, maybe such aliens choose to remain clustered for reasons of efficiency (our own trend toward urbanization points to this, and lightspeed comms delays between stars would motivate it further).
My own bet however is that for every intelligent species the ultimate scarce resource is thermodynamic free energy - not matter or physical space. The neighborhood of a supermassive black hole is the obvious place to migrate to in this case, with more free energy than all the galaxy's stars combined. Perhaps such a migration is the final hard step, which would be not be especially visible to others.
I'm gonna be the pessimist here. What if, evolving "intelligence" is easy given enough time BUT its actually an evolutionary DIS-advantage? As in, if a species becomes intelligent, it tends to inevitably self-destroy? So basically, if a species develops intelligence it will inevitable destroy itself before it gets to do any kind of Star Trek like expansion or exploration.
If grabby aliens are grabbing territory in a direction we cannot yet see, then there is no evidence that we are early in the universe. We might be late. Most stars have already been formed. Maybe most aliens have already left visible space.
> intelligent life at our level was largely inevitable on a planet like ours
“Like ours” is doing a lot of work here. Depending on what that means, life and intelligence *are* inevitable on such a planet, but how many of the ~10^24 stars have a planet like ours? How similar must it be?
I am convinced that life will either expand or disappear. But we can see that it has not expanded into the space we can see with our telescopes. By now we could see K3 civs anywhere, or K2 if they’re close enough. So either we are the first, or else life expands in a direction we cannot see.
This is an optimistic solution to the great silence, and allows for a great many aliens to have already evolved to the point they can move in this direction we cannot see.
In short, interstellar expansion is a lower return on investment than expansion in this other direction, and once life is advanced enough to see this direction, it will never choose the low ROI path. The great filter is good news, not bad. In this story, the filter is aliens graduating to a new level.
Kipling seems correct to me regarding small chance of evolution into 'grabby aliens'. If we assume population dynamics similar to that of humans in this hypothetical civilization, the population stops expanding at some point, making space exploration a waste of resources in short time. This would change if the malthusian trap somehow persists there due to concentration of power in few hands, but such people would care less abut the situation of their populace, and wouldn't want to spend money on what they wouldn't get. So the probability of this kind of aliens must be very small.
> >Hanson's model not only assumes hard steps, but also that the number of hard steps is a universal value on every planet and moon out there.
> As step difficulties vary over such a wide range, if there are a wide range of possible hard steps paths, the most likely number of steps is probably far more likely than other numbers.
This variation matters, and has that implication, if there is no correlation between the types / number of steps and the resulting types of life and its trajectory. As one path, imagine there is a simpler metabolic path that allows the rise of intelligent life centered on deep ocean-vents which is vanishingly unlikely to be able to get past basic tool use due to limited range, pressure differentials, etc. - the conditions may be common, lots of such intelligent life could evolve, and we'd essentially never see it.
Interestingly, it seems that there is a simple change that would make your view consistent with Kipping's view of extremely low grabby probability: Your current best explanation for UFOs-as-aliens involves them being quiet and extremely capable of coordinating so as to ensure they're quiet over large distances. It also involves them being our panspermia siblings. The simple change that would make your view consistent with Kipping's would be to relax the "nearby aliens must be our panspermia siblings" assumption. If the type of aliens invoked in your UFOs-as-aliens story did not limit their colonization-preventing activities to their own galaxy, and if they were an outlier in earliness, they could impose a filter of extremely low grabby probability (perhaps a flat 0) on a huge volume.
This is something I admit I don't understand about your apparent view: why does the 'nearby aliens as quiet panspermia siblings' hypotheses deserve some non-trivial probability and consideration while the 'nearby aliens as quiet travelers with distant origins' hypothesis seemingly deserves no such consideration (at least not enough to be worth writing about it, or even mentioning it, as a possibility)? If the former is granted as a non-crazy possibility, why isn't the latter?
The one thing that does give me pause about "intelligence" having a high chance of leading to "grabby technological civilization" is that we seem to have a decent-number of big-brained animals on Earth even across some pretty distant evolutionary separations (octopi are quite intelligent), but none of them except humans evolved into a potentially grabby civilization. Not even chimps and bonobos, who are close enough to humans that we can teach them sign language and they use primitive tools. It makes me wonder if it's extremely unusual for a species to line up the intelligence, potential for social organization, and general habitat flexibility to become a grabby civilization.
I'm hesitant to write off the M-dwarf planets as well. They have a pretty brutal pre-main sequence experience with their stars, and the smaller ones might just be too weak in sunlight intensity to sustain photosynthesis on any meaningful scale that could support a complex biosphere, but the more recent modeling on them suggests they could be quite habitable - in some ways more habitable than Earth for longer periods of time, since they're much more resilient against either runaway greenhouse effects or snowball glaciation epochs.
Two parameters seem crucial: 1) will our civ become grabby? It's not so obvious to me but Robin seems to think it's super likely. 2) Are we very early? If M dwarfs are habitable then yes, if not then no.
Robin if you thought p(grabiness | our civ) was low and p(life | M dwarf) was very close to zero, would you update your predictions in Kipping's direction?
I agree that not believing in try-try hard steps is sort of silly, they seem a priori very plausible and our prior that they exist should be >>0 even without just looking at the history of biological evolution. But it does seem like if M dwarfs were not habitable that should change the space of hypotheses quite a bit.
I wonder if this distinction between a "hard steps" model, and an environmentally-driven model like Kipling proposes (and Mills et al in the paper Robin posted a few days ago), is something of a false dichotomy. It's clear that environmental changes in Earth's history did play gating roles at certain points (the cessation of the Late Heavy Bombardment, the oxygenation of the atmosphere). How do we meaningfully distinguish between a lock that is very difficult to pick, and a lock with constantly-changing internals that becomes much easier to pick when conditions align.
Very interesting ideas here. Kipping's hypothesis of "a crazy small chance that intelligence like ours gives rise to a distantly-visible civilization" doesn't necessarily imply a great filter in our future. It could be that most intelligent life wants to advance in a direction that isn't distantly visible. For example, maybe such aliens choose to remain clustered for reasons of efficiency (our own trend toward urbanization points to this, and lightspeed comms delays between stars would motivate it further).
My own bet however is that for every intelligent species the ultimate scarce resource is thermodynamic free energy - not matter or physical space. The neighborhood of a supermassive black hole is the obvious place to migrate to in this case, with more free energy than all the galaxy's stars combined. Perhaps such a migration is the final hard step, which would be not be especially visible to others.
I'm gonna be the pessimist here. What if, evolving "intelligence" is easy given enough time BUT its actually an evolutionary DIS-advantage? As in, if a species becomes intelligent, it tends to inevitably self-destroy? So basically, if a species develops intelligence it will inevitable destroy itself before it gets to do any kind of Star Trek like expansion or exploration.
I don't think a heavily populated post-biological Dyson Sphere is very bad news for our future, do you?
If grabby aliens are grabbing territory in a direction we cannot yet see, then there is no evidence that we are early in the universe. We might be late. Most stars have already been formed. Maybe most aliens have already left visible space.
> intelligent life at our level was largely inevitable on a planet like ours
“Like ours” is doing a lot of work here. Depending on what that means, life and intelligence *are* inevitable on such a planet, but how many of the ~10^24 stars have a planet like ours? How similar must it be?
I am convinced that life will either expand or disappear. But we can see that it has not expanded into the space we can see with our telescopes. By now we could see K3 civs anywhere, or K2 if they’re close enough. So either we are the first, or else life expands in a direction we cannot see.
This is an optimistic solution to the great silence, and allows for a great many aliens to have already evolved to the point they can move in this direction we cannot see.
In short, interstellar expansion is a lower return on investment than expansion in this other direction, and once life is advanced enough to see this direction, it will never choose the low ROI path. The great filter is good news, not bad. In this story, the filter is aliens graduating to a new level.
Kipling seems correct to me regarding small chance of evolution into 'grabby aliens'. If we assume population dynamics similar to that of humans in this hypothetical civilization, the population stops expanding at some point, making space exploration a waste of resources in short time. This would change if the malthusian trap somehow persists there due to concentration of power in few hands, but such people would care less abut the situation of their populace, and wouldn't want to spend money on what they wouldn't get. So the probability of this kind of aliens must be very small.
> >Hanson's model not only assumes hard steps, but also that the number of hard steps is a universal value on every planet and moon out there.
> As step difficulties vary over such a wide range, if there are a wide range of possible hard steps paths, the most likely number of steps is probably far more likely than other numbers.
This variation matters, and has that implication, if there is no correlation between the types / number of steps and the resulting types of life and its trajectory. As one path, imagine there is a simpler metabolic path that allows the rise of intelligent life centered on deep ocean-vents which is vanishingly unlikely to be able to get past basic tool use due to limited range, pressure differentials, etc. - the conditions may be common, lots of such intelligent life could evolve, and we'd essentially never see it.
Interestingly, it seems that there is a simple change that would make your view consistent with Kipping's view of extremely low grabby probability: Your current best explanation for UFOs-as-aliens involves them being quiet and extremely capable of coordinating so as to ensure they're quiet over large distances. It also involves them being our panspermia siblings. The simple change that would make your view consistent with Kipping's would be to relax the "nearby aliens must be our panspermia siblings" assumption. If the type of aliens invoked in your UFOs-as-aliens story did not limit their colonization-preventing activities to their own galaxy, and if they were an outlier in earliness, they could impose a filter of extremely low grabby probability (perhaps a flat 0) on a huge volume.
This is something I admit I don't understand about your apparent view: why does the 'nearby aliens as quiet panspermia siblings' hypotheses deserve some non-trivial probability and consideration while the 'nearby aliens as quiet travelers with distant origins' hypothesis seemingly deserves no such consideration (at least not enough to be worth writing about it, or even mentioning it, as a possibility)? If the former is granted as a non-crazy possibility, why isn't the latter?
The one thing that does give me pause about "intelligence" having a high chance of leading to "grabby technological civilization" is that we seem to have a decent-number of big-brained animals on Earth even across some pretty distant evolutionary separations (octopi are quite intelligent), but none of them except humans evolved into a potentially grabby civilization. Not even chimps and bonobos, who are close enough to humans that we can teach them sign language and they use primitive tools. It makes me wonder if it's extremely unusual for a species to line up the intelligence, potential for social organization, and general habitat flexibility to become a grabby civilization.
I'm hesitant to write off the M-dwarf planets as well. They have a pretty brutal pre-main sequence experience with their stars, and the smaller ones might just be too weak in sunlight intensity to sustain photosynthesis on any meaningful scale that could support a complex biosphere, but the more recent modeling on them suggests they could be quite habitable - in some ways more habitable than Earth for longer periods of time, since they're much more resilient against either runaway greenhouse effects or snowball glaciation epochs.
Two parameters seem crucial: 1) will our civ become grabby? It's not so obvious to me but Robin seems to think it's super likely. 2) Are we very early? If M dwarfs are habitable then yes, if not then no.
Robin if you thought p(grabiness | our civ) was low and p(life | M dwarf) was very close to zero, would you update your predictions in Kipping's direction?
I agree that not believing in try-try hard steps is sort of silly, they seem a priori very plausible and our prior that they exist should be >>0 even without just looking at the history of biological evolution. But it does seem like if M dwarfs were not habitable that should change the space of hypotheses quite a bit.
I wonder if this distinction between a "hard steps" model, and an environmentally-driven model like Kipling proposes (and Mills et al in the paper Robin posted a few days ago), is something of a false dichotomy. It's clear that environmental changes in Earth's history did play gating roles at certain points (the cessation of the Late Heavy Bombardment, the oxygenation of the atmosphere). How do we meaningfully distinguish between a lock that is very difficult to pick, and a lock with constantly-changing internals that becomes much easier to pick when conditions align.