I know that the mainstream view on Lesswrong is that we aren’t observing alien aircraft, so I doubt many here will disagree with the conclusion. But I wonder if people here agree with this particular argument for that conclusion. Basically, I claim that:
P[aliens] is fairly high, but
P[all observations | aliens] is much lower than P[all observations | no aliens], simply because it’s too strange that all the observations in every category of observation (videos, reports, etc.) never cross the “conclusive” line.
As a side note: I personally feel that P[observations | no aliens] is actually pretty low, i.e. the observations we have are truly quite odd / unexpected / hard-to-explain-prosaically. But it’s not as low as P[observations | aliens]. This doesn’t matter to the central argument (you just need to accept that the ratio P[observations | aliens] / P[observations | no aliens] is small) but I’m interested if people agree with that.
I think the evidence against (most) miracles is stronger because they violate the laws of physics. Although I think the same could be said for a few UAPs—if a UAP moves in a way that is physically impossible as far as we know, that’s strong evidence against it being aliens, because aliens still have to follow the laws of physics.
How would a tic-tac to accelerate at 700g with no visible propulsion, even positing the existence of super-advanced technology? The best I can think of off the top of my head is that it’s using an extremely strong magnet to manipulate its position relative to earth’s magnetic field. But that would require an absurd amount of energy so it would probably need to be powered by a tiny cold fusion reactor (which may be physically impossible), and it would still need to avoid emitting noticeable amounts of heat, and even if it has some sort of hyper-insulating shell, it would need internal parts that don’t evaporate under that much heat, and also need to avoid emitting the massive amount of heat that would be generated by friction with the air.
You do your argument a disservice when you conflate “laws of physics” with “extrapolations of current materials and energy engineering”.
If speed of light isn’t violated, and the force involved isn’t so great that the reaction would be measurable as changes in earth rotation or something, and the energy is much less than the theoretical limit of a small amount of antimatter, it’s not “laws of physics” that is the constraint.
Note I’m not saying you’re wrong in considering it very unlikely, but hyperbole doesn’t help in thinking or in discussion (here on LW, at least—it’s common and perhaps useful in other contexts).
Even if there are aliens, and humans do sometimes gain data showing such, if the aliens are sufficiently advanced and don’t want to be found, I would not be surprised if they selectively took away our conclusive data but left behind the stuff that’s already indistinguishable from noise. Kinda like how we take our trash with us after hiking and camping, but don’t worry too much in most places about our footprints or the microscopic bits of material our gear and bodies leave behind.
Glitches happen. Misunderstandings happen. Miscommunications happen. Coincidences happen. Weird-but-mundane things happen. Hoaxes happen. To use machine learning terminology, the real world occurs at temperature 1. We shouldn’t expect P[observations] to be high—that would require temperature less than 1. The question is, is P[observations] surprisingly low, or surprisingly high for some different paradigm, to such an extent as would provide strong evidence for something outside of current paradigms? My assessment is no. (see my discussion of Nimitz for example)
Some additional minor remarks specifically on P[aliens]:
non-detection of large (in terms of resource utilization) alien civilizations implies that the density of interstellar-spacefaring civilizations is low—I don’t expect non-expansion to be the common (let alone overwhelmingly selected) long term choice, and even aestivating civilizations should be expected to intervene to prevent natural entropy generation (such as by removing material from stars to shut them down)
If the great filter (apart from the possible filter against resource-utilization expansion by interstellar-spacefaring civilizations, which I consider unlikely to be a significant filter as mentioned above) is almost entirely in the abiogenesis step, and interstellar panspermia isn’t too hard, then it would make sense for a nearby civilization to exist as Robin Hanson points out. I do actually consider it fairly likely that a lot of the great filter is in abiogenesis, but note that there needs to be some combination of weak additional filter between abiogenesis and spacefaring civilization or highly efficient panspermia for this scenario to be likely.
If a nearby, non-expanding interstellar-spacefaring civilization did exist, then of course it could, if it so chose, mess with us in a way that left hints but no solid proof. They could even calibrate their hints across multiple categories of observations, and adjust over time, to match our capabilities. However, I don’t think them choosing to do this is particularly likely a priori. If someone assumes that such aliens exist and are responsible for UAPs, while also noting that we haven’t seen clear proof of their existence, then their posterior may assign a high probability to this—but I would caution against recycling the posterior into the prior.
(Edit: switched things around to put the important stuff in the first paragraph)
The general point that you need to update on the evidence that failed to materialize is in the sequences and is exactly where I expected you to go based on your introductory section.
I know that the mainstream view on Lesswrong is that we aren’t observing alien aircraft, so I doubt many here will disagree with the conclusion. But I wonder if people here agree with this particular argument for that conclusion. Basically, I claim that:
P[aliens] is fairly high, but
P[all observations | aliens] is much lower than P[all observations | no aliens], simply because it’s too strange that all the observations in every category of observation (videos, reports, etc.) never cross the “conclusive” line.
As a side note: I personally feel that P[observations | no aliens] is actually pretty low, i.e. the observations we have are truly quite odd / unexpected / hard-to-explain-prosaically. But it’s not as low as P[observations | aliens]. This doesn’t matter to the central argument (you just need to accept that the ratio P[observations | aliens] / P[observations | no aliens] is small) but I’m interested if people agree with that.
I make no claim to speak for anyone who isn’t me, but I agree with your analysis. I would say similar things about e.g. ESP and miracles and the like.
I think the evidence against (most) miracles is stronger because they violate the laws of physics. Although I think the same could be said for a few UAPs—if a UAP moves in a way that is physically impossible as far as we know, that’s strong evidence against it being aliens, because aliens still have to follow the laws of physics.
How would a tic-tac to accelerate at 700g with no visible propulsion, even positing the existence of super-advanced technology? The best I can think of off the top of my head is that it’s using an extremely strong magnet to manipulate its position relative to earth’s magnetic field. But that would require an absurd amount of energy so it would probably need to be powered by a tiny cold fusion reactor (which may be physically impossible), and it would still need to avoid emitting noticeable amounts of heat, and even if it has some sort of hyper-insulating shell, it would need internal parts that don’t evaporate under that much heat, and also need to avoid emitting the massive amount of heat that would be generated by friction with the air.
You do your argument a disservice when you conflate “laws of physics” with “extrapolations of current materials and energy engineering”.
If speed of light isn’t violated, and the force involved isn’t so great that the reaction would be measurable as changes in earth rotation or something, and the energy is much less than the theoretical limit of a small amount of antimatter, it’s not “laws of physics” that is the constraint.
Note I’m not saying you’re wrong in considering it very unlikely, but hyperbole doesn’t help in thinking or in discussion (here on LW, at least—it’s common and perhaps useful in other contexts).
Ok, fair point, I was going too far in assuming that the sort of engineering necessary was physically impossible.
Even if there are aliens, and humans do sometimes gain data showing such, if the aliens are sufficiently advanced and don’t want to be found, I would not be surprised if they selectively took away our conclusive data but left behind the stuff that’s already indistinguishable from noise. Kinda like how we take our trash with us after hiking and camping, but don’t worry too much in most places about our footprints or the microscopic bits of material our gear and bodies leave behind.
Glitches happen. Misunderstandings happen. Miscommunications happen. Coincidences happen. Weird-but-mundane things happen. Hoaxes happen. To use machine learning terminology, the real world occurs at temperature 1. We shouldn’t expect P[observations] to be high—that would require temperature less than 1. The question is, is P[observations] surprisingly low, or surprisingly high for some different paradigm, to such an extent as would provide strong evidence for something outside of current paradigms? My assessment is no. (see my discussion of Nimitz for example)
Some additional minor remarks specifically on P[aliens]:
non-detection of large (in terms of resource utilization) alien civilizations implies that the density of interstellar-spacefaring civilizations is low—I don’t expect non-expansion to be the common (let alone overwhelmingly selected) long term choice, and even aestivating civilizations should be expected to intervene to prevent natural entropy generation (such as by removing material from stars to shut them down)
If the great filter (apart from the possible filter against resource-utilization expansion by interstellar-spacefaring civilizations, which I consider unlikely to be a significant filter as mentioned above) is almost entirely in the abiogenesis step, and interstellar panspermia isn’t too hard, then it would make sense for a nearby civilization to exist as Robin Hanson points out. I do actually consider it fairly likely that a lot of the great filter is in abiogenesis, but note that there needs to be some combination of weak additional filter between abiogenesis and spacefaring civilization or highly efficient panspermia for this scenario to be likely.
If a nearby, non-expanding interstellar-spacefaring civilization did exist, then of course it could, if it so chose, mess with us in a way that left hints but no solid proof. They could even calibrate their hints across multiple categories of observations, and adjust over time, to match our capabilities. However, I don’t think them choosing to do this is particularly likely a priori. If someone assumes that such aliens exist and are responsible for UAPs, while also noting that we haven’t seen clear proof of their existence, then their posterior may assign a high probability to this—but I would caution against recycling the posterior into the prior.
(Edit: switched things around to put the important stuff in the first paragraph)
The general point that you need to update on the evidence that failed to materialize is in the sequences and is exactly where I expected you to go based on your introductory section.