An earlier post of mine reviewed the most credible evidence I have managed to find regarding seemingly anomalous UFOs. My aim in this post is to mostly set aside the purported UFO evidence and to instead explore whether we can justify placing an extremely low probability on the existence of near aliens, irrespective of the alleged UFO evidence. (By “near aliens”, I mean advanced aliens on or around Earth.)
Specifically, after getting some initial clarifications out of the way, I proceed to do the following:
- I explore three potential justifications for a high level of confidence (>99.99 percent) regarding the absence of near aliens: (I) an extremely low prior, (II) technological impossibility, and (III) expectations about what we should observe conditional on advanced aliens being here.
- I review various considerations that suggest that these potential justifications, while they each have some merit, are often overstated.
- For example, in terms of what we should expect to observe conditional on advanced aliens having reached Earth, I argue that it might not look so different from what we in fact observe.
- In particular, I argue that near aliens who are entirely silent or only occasionally visible are more plausible than commonly acknowledged. The motive of gathering information about the evolution of life on Earth makes strategic sense relative to a wide range of goals, and this info gain motive is not only compatible with a lack of clear visibility, but arguably predicts it.
- For example, in terms of what we should expect to observe conditional on advanced aliens having reached Earth, I argue that it might not look so different from what we in fact observe.
- I try to give some specific probability estimates — Bayesian priors and likelihoods on the existence of near aliens — that seem reasonable to me in light of the foregoing considerations.
- Based on these probability estimates, I present simple Bayesian updates of the probability of advanced aliens around Earth under different assumptions about our evidence.
- I argue that, regardless of what we make of the purported UFO evidence, the probability of near aliens seems high enough to be relevant to many of our decisions, especially those relating to large-scale impact and risks.
- Lastly, I consider the implications that a non-negligible probability of near aliens might have for our future decisions, including the possibility that our main influence on the future might be through our influence on near aliens.
I think you have to update against the UFO reports being veridical descriptions of real objects with those characteristics because of just how ludicrous the implied properties are. This paper says 5370 g as a reasonable upper bound on acceleration, implying with some assumptions about mass an effective thrust power on the order of 500 GW in something the size of a light aircraft, with no disturbance in the air either from the very high hypersonic wake and compressive heating or the enormous nuclear explosion sized bubble of plasmafied air that the exhaust and waste heat emissions something like this would produce.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7514271/
At a minimum, to stay within the bounds of mechanics and thermodynamics, you'd need to be able to ignore airflow and air resistance entirely, have the ability to emit reaction mass in a completely non-interacting form, and the ability to emit waste energy in a completely non-interacting form as well.
To me, the dynamical characteristics being this crazy points far more towards some kind of observation error, so I don't think we should treat them as any kind of real object with those properties until we can conclusively rule out basically all other error sources.
So even if the next best explanation is 100x worse at explaining the observations, I'd still believe it over a 5000g airflow-avoiding craft that expels invisible reaction mass and invisible waste heat while maneuvering. Maybe not 10,000x worse since it doesn't outright contradict the laws of physics, but still the prior on this even being technically possible with any amount of progress is low, and my impression (just from watching debates back and forth on potential error sources) is that we can't rule out every mundane explanation with that level of confidence.
Thanks for your comment. I basically agree, but I would stress two points.
First, I'd reiterate that the main conclusions of the post I shared do not rest on the claim that extraordinary UFOs are real. Even assuming that our observed evidence involves no truly remarkable UFOs whatsoever, a probability of >1 in 1,000 in near aliens still looks reasonable (e.g. in light of the info gain motive), and thus the possibility still seems (at least weakly) decision-relevant. Or so my line of argumentation suggests.
Second, while I agree that the wild abilities are... (read more)