Tag Archives: Aliens

An Alien War Nightmare

Grabby aliens are advanced civs who change the stuff they touch in big visible ways, and who keep expanding fast until they meet each other. Our recent analysis suggests that they appear at random stars roughly once per million galaxies, and then expand at roughly half the speed of light. Right now, they have filled roughly half of the universe, and if we join them we’ll meet them in roughly a billion years. There may be far more quiet than grabby alien civs out there, but those don’t usually do much or last long, and even the ruins of the nearest are quite far away.

While I’ve so far avoided thinking about much war within this scenario, I’ve decided to go there now. So here we go.

First, consider quiet alien wars. Such quiet civs may have internal wars, but different civs rarely get close enough to each other for physical fights. Maybe more advanced ones would sometimes conquer less advanced ones via malicious messages, but I’m skeptical that such events are common. The rare civs who expanded long and quietly mainly to preserve a natural universe and prevent grabby origins within their sphere of control should share goals and thus have little reason to war when they meet. Furthermore, when grabby civs meet quiet ones, abilities would be terribly unequal, and so not much of an occasion for war.

What about grabby civs? After a few million years they’d probably reach near max possible tech abilities. Which I guess makes them pretty immune to malicious messages. But such civs and their parts might vary in how well they had used a shared origin to promote internal cooperation. And a lack of perfect cooperation would likely result in some internal wars. The higher the rate at which they spend a fraction of their fast-access resources to fight or prevent fights, the faster they’d use up such resources. As a result, such fast spending civs might only get resources for a long time if some of their resource sources, like black holes, only allowed slow extraction.

Long-distance ballistic directed energy weapons, which couldn’t be redirected along the way, would only be of use on targets whose locations could be predicted long enough in advance. As a result, grabby cis would usually ensure that the locations of important resources vulnerable to such attacks could not be so predicted. Similarly, they’d end or stay away from objects like stars that might be induced to explode by outside prods. Thus militarily-useful resources would likely need to maintain unpredictable locations and would need to be located quite close to where they’d be used. So conflicts would tend to be won locally by those with more military resources locally available near the point of conflict.

If grabby civs are not more able to or inclined to cooperate internally than with other civs, then each small part of such a civ should be similarly wary of neighboring advanced life, regardless of its civ of origin. In which case, the boundary at which different grabby civs meet might not have that much significance. Who wins each local conflict would mainly depend on their relative size, resources, level of internal cooperation, and local geography, but not civ of origin. On 100Mlyr and larger scales, this should add up to a pretty uniform picture.

However, what if at least some parts of some grabby cigs could use their shared origin to cooperate more strongly internally than they could with other grabby civs? In this case, they’d expect more conflict at the border where grabby civs meet, compared to at other locations. As a result, the cooperating units on both sides might then try to send resources to that border, in anticipation of such conflicts. And then a key question arises: just how fast is it feasible to move militarily useful resources?

Grabby civs expanding at half the speed might seem surprisingly fast, but this does seem roughly feasible given that they can afford to spend huge resources on speeding tiny seeds that can then use local resources to quickly grow exponentially into huge civs. Alas, no similar exponential strategy seems available to move resources from one place to another. If the resources required to accelerate resources to near the speed of light can be efficiently recaptured at a designation location, then perhaps resources could in fact be efficiently sent very far very fast. But otherwise, sending resources far fast (e.g., >2% of c) may only be possible at crazy high costs.

At the border between two grabby civs, imagine that one of the civs had better managed to tax internal regions to send more resources to that border from within that civ, and at a very rapid speed. In this case, then after a while the resources accumulated on one side of that border might be far larger than that on the other side. Then if the natural advantage of defense over offense were not too large, the stronger side might be able to initiate a war and take territory from the other side. And in fact this outcome might become so obvious that the losing side would be very sure to lose, and not even want to fight.

If merely threatening to attack with overwhelming force was usually sufficient to quickly rout the weaker side and win new territory, via induced surrender or flight, or if actual fights did not take too long or destroy too much of an attacker’s resources, then an attacker might continue to move forward into the other side’s territory at a rapid pace. And if that pace were on the order of 2% of the speed of light, that might be sufficient to completely take over all the territory of a neighboring grabby civ within the roughly hundred billion years remaining before the time when, it is now estimated, dark energy makes galaxy clusters disconnected, never more able to see or reach each other. Such attack threats might then be seen as existential risks to such a civ.

Putting this all together seems to me to create a nightmare scenario, one which might greatly worry many young grabby civs who take very long term views. And, importantly, they’d have to decide how scared to be of this scenario long before they had much info on each particular neighboring civ, or even on any other civs besides themselves. Thus fear of the unknown might push many such civs into paying huge costs to maintain strong governance able to heavily tax internal activity to fund the movement of large amounts of resources out to be ready for unknown future border conflicts. Resources which might be mostly wasted if two such well-prepared civs were to meet.

Thus the possibilities of (A) long term civ-level views, (B) cheap fast movement of military resources which were hard to convert back to civilian use, (C) a sufficiently low advantage of defense over offense, (D) within-civ governance strong enough to tax and transfer resources to the border, and (E) weak enough governance unable to prevent your side from fleeing or surrendering given overwhelming attackers, all of this together might induce the waste of much, or perhaps even the vast majority of, available resources. Resources that could instead be used to compute far more meaningful peaceful lives near where the required resources sat originally.

Also note that at the line-shaped borders where three grabby civs meet, all three might have equal resources. Even so, two of them allying against the third would gain an advantage. And if this were sufficient, they might together advanced into the third region, sharing the gains. After which, each of them might have a geometric advantage, partially encircling the other side where their border bends. The possibility of this ally advantage should induce grabby civs to try to seem more similar to each other, to induce others to ally with them.

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Cook’s Critique of Our Earliness Argument

Tristan Cook has posted an impressive analysis, “Replicating and extending the grabby aliens model.” We are grateful for his detailed and careful work. Cook’s main focus is on indexical inference, showing how various estimates depend on different approaches to indexical analysis. But he has an appendix, ‘Updating n on the time remaining”, wherein he elaborates a claim that some of our analysis is “problematic”, “a possible error”, is “incompatible” with his, and that

“These results fail to replicate Hanson et al.’s (2021) finding that (the implicit use of) SSA implies the existence of GCs in our future.”

In this post I respond to that critique.

Cook quotes our claim:

If life on Earth had to achieve n “hard steps” to reach humanity’s level, then the chance of this event rose as time to the n-th power. Integrating this over habitable star formation and planet lifetime distributions predicts >99% of advanced life appears after today, unless n < 3 and max planet duration <50Gyr. That is, we seem early.

He also replicates this key diagram of ours:

This shows that humanity looks very early unless we have a low value of either n (the number of hard steps needed to create advanced life like us) or Lmax (max habitable planet duration). We suggest that this be explained via a grabby-aliens-fill-the-universe deadline coming soon, though we admit that either very low n or very low Lmax are other possible explanations.

But Cook claims instead that “large n and large Lmax … are incompatible.” Why? He offers a simple Bayesian model with a uniform prior over n, equal numbers of two types of planets all born at the same time with lifetimes of 5 and 100 billion years, and updating on the fact that humans appeared on one of these planets after 4.5 billion years. He shows (correctly) that the Bayesian posterior then overwhelmingly favors n=1, with almost no weight on n>2.

But this seems to me to just repeat our point above, that without a grabby aliens deadline one needs to assume either low n or low Lmax. If you allow large Lmax with no deadline, that will force you to conclude low n; no surprise. (Also, it seems to me that all of Cook’s n estimates do not update on all of the varied evidence that has led other authors to estimate higher n.)

The body of Cook’s paper describes a much more elaborate Bayesian model, a model which includes the deadline effect. And the posteriors on Lmax there also very strongly favor low Lmax, for all the indexical reasoning cases that he considers. Does this show that Lmax is “incompatible” with large n?

No, because this result is easily attributed to the fact that his prior on Lmax strongly favors both low n and low Lmax. Cook considers three priors on n, with medians of 0,1,3. And while he allows Lmax to range from 5 to 20,000 Gyr, the median of his prior is ~10 Gyr. Even though actual median planet lifetime is 5,000 Gyr. An analysis that won’t allow large Lmax or large n can’t tell us is those two are compatible.

Note that the priors in Cook’s main Bayesian analysis are not designed to express great ignorance, but instead designed to agree with estimates from several prior papers that Cook likes. So Cook’s main priors exclude the possibilities that grabby alien civs might expand slowly, or that there are a great many non grabby civs for each grabby one. And he tunes his prior to ensure a median of exactly one intelligent civilization per observable universe volume.

However, in another appendix of Cook’s paper, “Varying the prior on Lmax”, he also considers a wider prior on Lmax. (He retains all his other prior choices, including a prior on n with median 1.) Namely a lognormal with a median of 500 Gyr and a one sigma range of 110 to 2200 Gyr. His posterior from this has a median Lmax of 7Gyr, and a 90th percentile at ~100 Gyr. Which means that compared to Cook’s prior on Lmax, his posterior has substantially lower values of Lmax. Does this prove his claim that high Lmax is incompatible with high n?

I think not, because 60% of this posterior is on cases with less than one grabby civ per observable universe volume, and it takes a much higher density of such civs to create a grabby aliens deadline effect.

Look, the fact that we now find ourselves on a planet that has only lasted for 4.5Gyr should boost low Lmax hypotheses in two ways. The first, and weaker effect, is that the lower is Lmax, the fewer planets there are below Lmax, and thus the higher becomes the prior on our particular planet. This is a count effect, which boosts our planet’s posterior by a factor of ten for every factor of one hundred by which Lmax falls. As the total dynamic range of Lmax under consideration here is a factor of 4000, that’s a real but modest effect.

The second effect is much larger. Without a grabby aliens deadline effect, then for n=1 a planet that lasts for 4000 times longer becomes 4000 times more likely to birth an intelligent civilization. For n=2, it becomes eight million times more likely. And this factor gets even bigger for larger n. Thus observing that we appear on a planet that has lasted only 4.5Gyr can force a huge additional update toward lower Lmax. Without a deadline, that’s the only way to explain how we appear on such a short lived planet if there is no grabby aliens deadline. This strong effect plausibly explains the strong Lmax updating effects we see in Cook’s wider Lmax prior analysis, as most of the posterior weight there is on scenarios with no deadline effect.

Bottom line: I happily admit there is a count effect that prefers lower Lmax in a posterior compared to a prior. But this effect is weak; a factor of ten in posterior per factor of one hundred in Lmax. This effect happens regardless of whether a grabby aliens deadline effect applies. But the other much stronger Lmax update effect is cancelled by a grabby aliens deadline. Yes, if aliens are so rare that there’s no deadline effect, the update toward low Lmax seems to be strong. But there is an important sense in which such a deadline is an alternate explanation to human earliness. This is what we claimed in our paper, and I don’t see that Cook’s analysis changes this conclusion.

P.S. Cook doesn’t actually simulate a stochastic model where alien civs arise then block each other. He instead uses a simple formula following “following Olson (2015).” So his distributions over civ size only include variance over time, but not other kinds of variance. I worry that this formula assumes an independence of alien volume locations that isn’t true. Though I doubt the errors from this simplification make that big of a difference.

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Our Level In the Great Filter

An exchange between Astrophysicist Charles Lineweaver and myself:

In their 2019 paper “The Timing of Evolutionary Transitions Suggests Intelligent Life is Rare”, Snyder-Beattie, Sandberg, Drexler, and Bonsall argue that the expected time for “intelligent life” to appear on Earth “likely exceed the lifetime of Earth, perhaps by many orders of magnitude” which “corroborate[s] the original argument suggested by Brandon Carter that intelligent life in the Universe is exceptionally rare.”

In a Feb. 2022 comment in Inference, “A Lonely Universe”, Charles Lineweaver disagreed:

The Snyder-Beattie et al. result depends on the assumption that … the major transitions that characterize our evolution happen elsewhere. There is little evidence in the history of life on earth to support this assumption. … transition to human-like intelligence or technological intelligence occurred only about 100,000 years ago and is species-specific. The latter trait is strong evidence we should not expect to find it elsewhere.

It [is not] reasonable to argue that … the features of life on earth … most likely to appear in life elsewhere are those that have evolved independently many times, such as complex multicellularity, eyes, wings, and canines. … [because] these … have only occurred within a unique [never-repeated] eukaryotic branch that represents a tiny fraction of the diversity of life on earth. …

Attempting to compute the probability of human-like intelligence elsewhere based on our lineage is akin to analyzing the evolution of the English language on earth and trying to use the timing of the Great Vowel Shift to estimate its timing on other planets

My July 2022 reply, also in Inference, says:

Lineweaver suggests that without good reasons to think “the major transitions that characterize our evolution happen elsewhere,” estimates regarding Earth do not allow us to make estimates regarding other planets.

On the contrary, I see two ways to compare planets so that Earth estimates become relevant for other planets, allowing us to infer a low overall rate at which advanced life appears elsewhere. First, if Earth is a random sample from planets that succeed in making life at our level, the success rate on Earth cannot be too different from the typical success rate on other such planets. Second, if there is a substantial chance that our descendants will soon become very visible in the universe, the fact that no other star in our galaxy has yet done so can set a low upper bound on the fraction of such stars that can have reached our level by now. …

Let R be the chance of life at our current level—i.e., controlling nuclear power and practicing spaceflight—appearing on a particular planet within some fixed planet habitability duration. … chance Q that, within the following ten million years, a planet at our level would give rise to a civilization that becomes permanently visible across its entire galaxy. [I elaborated with math examples for both these approaches.]

In that same place, Lineweaver then responded:

I don’t believe in the general group that he and many others call “advanced life.” … No other life-forms in the universe will be genetically or phenotypically more similar to us than chimps, bonobos, gorillas, naked mole rats, or frogs. Since Hanson and many others exclude our closest relatives from “advanced life,” they are—by their definition—not talking about a generic group with other members. …

On Earth, humans are the only ones who have become humans at our level of technology. To then conclude that among all species, our species had an average chance of becoming humans at our level is meaningless. …

Morris … argues that strong selection pressure leads to convergent evolution which then produces human-like intelligence. Hanson and most physicists subscribe to this view, but most biologists and I don’t. … Hanson refers to … life at our level … I … ask: If we exclude our species from consideration, does this talk of levels make any sense when applied to the rest of life? Are dogs or red oak trees at a higher level?

Reading Lineweaver’s response, I see my reply was off target; his issue is with the very idea of “life at our level”. So let me try again.

A key datapoint is this: we do not now see any big visible civilizations (BVC) in the sky who have greatly changed the natural universe into something more to their liking. In order to explain this fact, we must postulate a “great filter”, i.e., a process whereby simple dead matter might give rise first to simple life, and then to a BVC, or various filter obstacles might end this progress, so that it never produces a BVC. We must conclude that so far, averaging across the universe, this filter process has a very low total pass-through rate to a BVC. After all, no dead matter in the entire universe has yet given rise to a BVC we can see. That is, this great filter is on average very large.

In contrast, Earth today seems to plausibly have a much higher rate for creating BVC. I’d say we have at least a one in a million chance of doing so within the next ten million years. (This isn’t value judgement, just an estimate.) As Earth is now thus much closer to this BVC endpoint than it was originally, there is a sense in which Earth has now passed through part of the great filter, so that a substantially smaller filter lies before us than once lied before a simple dead Earth.

To talk about how much of the great filter we have so far passed, we’d like a way to talk about where we “are now” in this filter process. And this is where we can want to talk about our current “level” along some linear path from dead matter to BVC. But, as Lineweaver points out, evolution is in many ways a tree, instead of a line, and we cannot construct such a level concept merely by creating a conjunct of various random specific features of our species and planet.

Even so, I do think there are useful ways to define “our level” (OL) within the great filter. What we want is an equivalence class OL of alien civilization-moments such that (a) Earth today is in OL, (b) almost all BVC were once in OL at some prior point in their history, and (c) OL covers only a short “time slice” during which few civilizations go extinct. If we have more choices, we’d further like to pick OL so that (d) it minimizes the variance in the (coarse-grained) chance that each civilizations in OL later gives rise to a BVC. The lower this variance, the more it makes sense to talk in terms of the average chance within OL of giving rise later to a BVC.

One option would be to just define OL as the class that meets criteria (a,b,c) and actually minimizes (d). But while this might be well defined, it seems unwieldy. Which is why I tried above to define OL above in terms of a civilization having just mastered the basics of both nuclear power and spaceflight. It might be reasonable to add a few other techs to this list, such as computers.
Sure, we’d define somewhat different OL sets if we added or cut techs from this list. But the key point is that any civilization that had mastered all of them would be well on its way to being able to start a BVC soon. And most likely the chance of extinction is low between the point of having mastered half of these techs and mastering all of them. Thus the exact list of techs in our OL definition probably doesn’t make that much difference.

Yes, this way to define OL can let humans pass through OL, while chimps never do. But I just don’t see why that’s a problem. There is in fact a big important difference between what humans and chimps have accomplished, and I’m fine with our OL definition reflecting that.

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UFOs as US PsychOp

UFOs are objects in the sky that often seem to display amazing physical abilities. We have four main categories of theories to explain them. Under two kinds of theories, these abilities are illusory: (A) They could be errors, delusions, and misunderstandings, like seeing Venus or swamp gas. Or (B), they could be lies and hoaxes, intended to fool others. Under the other two kinds of theories, these abilities are real: (C) They are from aliens. Or (D) they are from Earth orgs that have been hiding their amazing abilities.

To estimate the chance of each kind of theory, one should multiply a prior chance for each type, a chance which ignores any concrete evidence of actual sightings, times a posterior chance that if each theory were true, we’d see the sort of sightings evidence that we do. (Renormalize these products to get posteriors.) A year ago I argued that the prior chance on the aliens theory wasn’t nearly as low as many seem to think; its much higher than in a typical murder trial, for example. So you have to actually look at the sightings evidence to judge its posterior chance, just as you would in a murder trial.

Today I want to consider the hoax category. In particular I want to consider the following hoax conspiracy theory: some part of the US government has, since the 1940s, had a long-term campaign to pay people to lie about seeing UFOs, and to make fake evidence to fool others into thinking they saw objects with amazing abilities. Of course once enough people heard about these events, then most reported sightings after that might be errors, delusions, and misunderstandings.

During the Second World War, the US government managed some pretty large and effective conspiracies. Such as the Manhattan project and the many ways they mislead Germany about our D-Day invasion. They seem thus to have then been roughly capable of managing a large UFO conspiracy. But, yes, the duration of this purported conspiracy would be much longer than in these prior examples.

Those prior successful conspiracies were also more closely related to military activities. Do we have evidence of a US ability or inclination regarding conspiracies more distant from military operations? Yes, in fact. The US had large and successful efforts, kept hidden for many decades, to move the fashion in art and writing away from Soviet styles, toward “modern” US styles. To make the US seem more prestigious relative to the USSR in the world’s eyes.

Okay, but what might the US government see itself as standing to gain from such a conspiracy? First, it is already known that the US government has promoted UFO groups in particular areas, and fed them false info on UFOs. They did this to “muddy the waters” regarding new tech that the US was developing and testing in the skies. Spies of foreign powers might plausibly hang near US testing facilities, and ask around around for reports of strange sightings. Such spies would get less useful info if local UFO groups are inclined to report many strange things unrelated to US tech testing.

In the Cold War, a big priority of the US military was to discourage enemies from launching a nuclear war against the US. And as an enemy is more likely to attack when then feel more confident of the consequences of their attack, one way to discourage such attacks is to muddy the waters re US military abilities, and re other possible powers who might react to such an attack. So if US could get enemy leaders to take UFO reports seriously, it could get those leaders to worry that they have underestimated US abilities, or that there are another hidden powers around.

Many UFO reports and interpretations have given the impression that the powers behind UFOs are especially interested in nuclear power and nuclear weapons, and that they fear or disapprove of such things. Enemy leaders who give credence to such reports might then fear that, if they initiated a nuclear attack, they’d suffer retaliation from such powers. Or maybe they’d just step in to take control after such a war weakened all of its participants.

I estimate roughly a one percent prior for this scenario, which is substantially higher than the prior I assigned to UFOs as aliens. Furthermore, this theory seems to quite naturally account for the key puzzles I struggled to explain regarding an aliens theory, namely that they are here while the universe looks empty, and that they stay near the limits of our vision, neither making themselves clearly visible nor completely invisible. This hoax category thus has the strongest posterior, in my view. (Yes I haven’t discussed the other two theory categories much; maybe I’ll say more on those some other day.)

Note that conditional on this UFO as US psychop theory being true, we should give more credence to other US conspiracy theories, such as that the US faked the moon landings. I thus now give more credence to this, even if I still see it as less likely than not. And conditional on believing other such theories, this UFO as US psychop theory becomes more believable.

Added 10a: As the two US WWII secrets I mentioned were kept for only a few years, some say large orgs can’t keep secrets longer than that. But the US kept secret for 41 years that it faked its excuse for the Vietnam war, and for 46 years that it spied on citizen phone calls via Project Minaret. KFC has kept its recipe secret for 70 years, and Coca-Cola has kept its secret for 130 years. Venice kept its glass-blowing methods secret for many centuries, and China kept secret its methods of making both silk and porcelain for over a thousand years.

Yes, there’s a difference between hidden and known secrets, but all else equal known secrets should be more vulnerable, as the curious can focus their efforts on revealing them. Much harder to focus efforts when searching for hidden secrets.

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Hello Alien Polls

Define a “hello” alien civilization as one that might, in the next million years, identify humans as intelligent & civilized, travel to Earth, & say “hello” by making their presence & advanced abilities known to us. I just asked 15 Twitter poll questions on such aliens, each of which got 200-300 responses. 

Respondents mostly agreed to estimate a high chance of having internal status hierarchies (78%), being artificial (68%), trying to talk to us (64%), having morals (64%), and being descended from land animals (60%). Respondents mostly agreed on a low chance of being green (27%), once having had a nuke war (34%), and having internal conflicts (34%). They mostly agreed on a middle estimate (46%) on how much morals we’d share with them.

Respondents were split into two groups with strongly opposing views regarding if they could talk in our language, or if they feel materially threatened by our descendants. Respondents seem basically confused, with nearly even choice among the four options, regarding if hello aliens came from two genders, have identifiable agents, want to impress and lead us, or are led by a single government. 

Here are the main ways I disagree: Any aliens arriving here now on Earth must be very old; recent origin would be an incredible timing coincidence. As we don’t see them elsewhere in the sky, they have somehow prevented themselves from greatly changing nearby galaxies. This suggests they are green, and have a world government to enforce green rules.

Which suggests their reason for visiting: to get us to go along with their green rules. And a way to do that is to look very impressive but not talk to us, as talking would likely reveal things about them we’d hate.

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Great Filter With Set-Backs, Dead-Ends

A biological cell becomes cancerous if a certain set of rare mutations all happen in that same cell before its organism dies. This is quite unlikely to happen in any one cell, but a large organism has enough cells to create a substantial chance of cancer appearing somewhere in it before it dies. If the chances of mutations are independent across time, then the durations between the timing of mutations should be roughly equal, and the chance of cancer in an organism rises as a power law in time, with the power equal to the number of required mutations, usually around six.

A similar process may describe how an advanced civilization like ours arises from a once lifeless planet. Life may need to advance through a number of “hard step” transitions, each of which has a very low chance per unit time of happening. Like evolving photosynthesis or sexual reproduction. But even if the chance of advanced life appearing on any one planet before it becomes inhabitable is quite low, there can be enough planets in the universe to make the chance of life appearing somewhere high.

As with cancer, we can predict that on a planet lucky enough to birth advanced life, the time durations between its step transitions should be roughly equal, and the overall chance of success should rise with time as the power of the number of steps. Looking at the history of life on Earth, many observers have estimated that we went through roughly six (range ~3-12) hard steps.

In our grabby aliens analysis, we say that a power of this magnitude suggests that Earth life has arrived very early in the history of the universe, compared to when it would arrive if the universe would wait empty for it to arrive. Which suggests that grabby aliens are out there, have now filled roughly half the universe, and will soon fill all of it, creating a deadline soon that explains why we are so early. And this power lets us estimate how soon we would meet them: in roughly a billion years.

According to this simple model, the short durations of the periods associated with the first appearance of life, and with the last half billion years of complex life, suggest that at most one hard step was associated with each of these periods. (The steady progress over the last half billion years also suggests this, though our paper describes a “multi-step” process by which the equivalent of many hard steps might be associated with somewhat steady progress.)

In an excellent new paper in the Proceedings of the Royal Society, “Catastrophe risk can accelerate unlikely evolutionary transitions”, Andrew Snyder-Beattie and Michael Bonsall extend this standard model to include set-backs and dead-ends.

Here, we generalize the [standard] model and explore this hypothesis by including catastrophes that can ‘undo’ an evolutionary transition. Introducing catastrophes or evolutionary dead ends can create situations in which critical steps occur rapidly or in clusters, suggesting that past estimates of the number of critical steps could be underestimated. (more)

Their analysis looks solid to me. They consider scenarios where, relative to the transition rate at which a hard step would be achieved, there is a higher rate of a planet “undoing” its last hard step, or of that planet instead switching to a stable “stuck” state from which no further transitions are possible. In this case, advanced life is achieved mainly in scenarios where the hard steps that are vulnerable to these problems are achieved in a shorter time than it takes to undo or stuck them.

As a result, the hard steps which are vulnerable to these set-back or dead-end problems tend to happen together much faster than would other sorts of hard steps. So if life on early Earth was especially fragile amid especially frequent large asteroid impacts, many hard steps might have been achieved then in a short period. And if in the last half billion years advanced life has been especially fragile and vulnerable to astronomical disasters, there might have been more hard steps within that period as well.

Their paper only looks at the durations between steps, and doesn’t ask if these model modifications change the overall power law formula for the chance of success as a function of time. But my math intuition is telling me it feels pretty sure that the power law dependence will remain, where the power now goes as the number of all these steps, including the ones that happen fast. Thus as these scenarios introduce more hard steps into Earth history, the overall power law dependence of our grabby aliens model should remain but become associated with a higher power. Maybe more like twelve instead of six.

With a higher power, we will meet grabby aliens sooner, and each such civilization will control fewer (but still many) galaxies. Many graphs showing how our predictions vary with this power parameter can be found in our grabby aliens paper.

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How Do Aliens Differ?

Someone recently tweeted the question of if aliens would be more or less benevolent than us. My first reaction was “how could we possibly know how we differ from aliens?” But on reflection, that was hasty, and it seems that we could productively think about how we may differ from aliens.

If we are talking about aliens that we might meet soon, one big obvious difference is that they’d be far more advanced. Because aliens substantially less advanced than us couldn’t meet anyone. If we are nearly the least advanced creatures who could possibly cause or recognize a meeting, then they are almost surely much more advanced. Also, the rareness of having exactly the same origin time (i.e., date at which one becomes advanced enough to meet) implies that any aliens we meet soon must have had an origin time long before us. Millions of years at least, and perhaps billions of years.

What about aliens that we might meet many millions of years in our future, when we are then far more advanced? Can we predict how they might differ from us then? Our best bet seems to be to predict how their past (relative to then) might have differed from our past, as we at least know many things about our history up to today. And the most interesting such differences in histories would be ones that might more strongly “lock in”, causing differences that persist until that future date.

But how can we predict differences in alien histories? One approach is to look for spectrums where we seem near one end. For example, at some point humans became an “apex predator”, who preyed on other creatures but where no other creatures preyed on them. As this is at the end of a spectrum, we can say that other aliens were either also once an apex predator, or they were not. So we might expect that on average ancestors of aliens were more afraid of being preyed upon than were our ancestors.

A second example is that only 5% of stars are more massive, and thus shorter-lived, than our stars. Which suggests that most aliens might be connected to longer-lived stars than ours. A third example is that political units like nations today are nearly the size of the world, even though they were far smaller in the past. Which suggests that aliens tended to have smaller political units, relative to their worlds.

Of course for any feature where our history seems to differ from possible alternatives, we have to wonder how much success (in the sense of giving rise to an alien civilization that might meet others) could be caused by that feature. For example, maybe big stars are more likely to give rise to life, or give life more metabolism to evolve faster. Maybe predators tend to be smarter, and smarter creatures are more likely to give rise to civilizations. Or maybe the formation of nearly world size political units is a prerequisite for expanding into the universe. The more plausible is a strong selection effect for a feature, the less plausible it is that we can predict how aliens differ on that feature.

Okay, I’ve suggested that it is possible in principle to think productively about this topic, but also that this doesn’t seem easy. But a first task seems relatively easy: just collect candidate lists of features where we seem plausibly different, and where selection effects may not be overwhelming. Seems such a project could even be crowd sourced, via asking many people to contribute suggestions. What do you think world, wanna do this together?

Some places maybe to start: kinds of stars and planets, and more generally over places aliens might be found. Alternate kinds of biospheres. Alternate kinds of smart or social creatures. Alternate structures of civilized societies.

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Think of the (Alien) Children!

If he was to lose his little finger to-morrow, he would not sleep to-night; but, provided he never saw them, he will snore with the most profound security over the ruin of a hundred millions of his brethren [in China].  Adam Smith

Among all the articles on UFOs I’ver read over the last half year, about half of them mentioned the possibility that some UFOs are aliens. But I can’t recall any giving thought to how such aliens might feel about the issue. Isn’t that awful self-centered of us? 

You may say that you can’t be bothered to empathize with only hypothetical creatures, and we just aren’t at all sure that UFO aliens exist. Fair enough. But then I will point you to grabby aliens; in my opinion we have strong enough evidence of their existence to say they are more likely to exist than not. If you recall, we need to explain why humans have arrived so early in the history of the universe, and a deadline set by grabby aliens who will soon fill up the universe seems our most robust explanation.

You may say that you can’t just take my word for this, that you must wait to see this argument endorse by standard academic astrophysics authorities. That, you say, is how “science” works. Fair enough. I hereby announce that our grabby aliens paper has been accepted for publication in one of the top astrophysics journals, aptly named Astrophysical Journal. (Here is a press release.) So now its not just speculation.

You may say that you still need to be sure they exist to care, and our results can’t support that level of certainty. But on the subject of global warming people often lament its effect on distant future generations, even though we can’t be sure that such future generations will exist. So you don’t need to be that sure, right?

You may argue that you’ll need to know more about these aliens before you can care about them. Fair enough. So let me tell you many things about them. They once were animals with minds and bodies like yours, but have since reimplemented themselves as artificial life. And they have been artificial life for millions of years; their tech is vastly more advanced than yours.

Even so, they are still more like you than all the other kinds of animals on Earth, as they should have trade, language, law, war, hierarchy, governance, tech, and much more. The first ones we meet will be frontier aliens, descendants of a long line who prioritized staying at the leading edge of expansion. At the expense of other things, such as world government. 

There, now do you know enough to care? Does it help to know that there are vastly more of them out there are humans on Earth?

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Brin’s UFO Questions

David Brin has some questions; I suggest some answers. His questions are indented; my answers are not.

I give a small chance that the much discussed “UAP” phenomena could – conceivably – be expendable drones or beam spots sent by such lurkers. Make that a VERY small chance. … ask some really fundamental questions, like: a) Why do UFO images keep getting fuzzier, when there are about a million times as many cameras than in the 1950s? 

The cameras that ordinary people have today aren’t higher resolution than they used to be, and ordinary people find it hard to take pictures of unexpected moving objects in the sky with camera phones. I don’t think the pictures are on average fuzzier today. Also, my theory suggests that their sources might be trying to stay near the edge of visibility. 

b) A whole lot depends on whether these sighted ‘UAPs’ are actually opaque physical objects that affect their surroundings and block passage of light from behind them! Or else, are they glowing spots of excited air that pass through light from the background behind them (translucent)? I have not seen this question even posed … == Cat lasers == My own hypothesis for what’s going on?  … very strong laser pointer. Go somewhere you can clearly see a wall many miles away. Like the Grand Canyon. Swipe left or right. If your wrist-flick was quick enough, that dot moved faster than the speed of light! … start with military laser systems for ionizing streaks of air and painting fake objects in the sky to serve as decoys. Here’s an excellent article. And what’s described is is impressively close!

This has been discussed, and this could well be the physical process behind many sightings. But if so, the abilities shown seem to be well beyond what has been revealed in our literature. Not only are these sometimes very large and bright “images”, but the beam source seems to be far away and well hidden. Hard to use this to explain sightings from decades ago, the US says it isn’t behind US sightings, and if some Earth power has this ability why is it revealing it to the world in this odd way?

are these glowing patches, blobs or “tic-tacs” radiating in just one or two colors? 

I think I recall data showing that at least for some night sightings the spectrums are broad. 

“I’ve never seen shock waves or ionization trails coming off them. … No acoustic booms?

Yes, that is one of the main puzzling features, and yes it might be explained via beam projection. 

Why do the vast majority of recent sightings appear to happen at US military training areas? 

I’m not sure this is true. We are much more inclined to believe military sighters, so they’d get more attention even if more sightings were not there. Remember that there have been over 100K sightings recorded over many decades. 

f) Getting back to fundamentals of motive and behavior: Why should we pay the slightest attention to “visitors” who behave like rude jerks? (Again, I say snub-em!)

Now, polymath Prof. Robin Hanson proposes they might have a reason for behaving this way. “To induce our cooperation, their plan is put themselves at the top of our status ladder. After all, social animals consistently have status ladders, with low status animals tending to emulate the higher. So if these aliens hang out close to us for a long time, show us their very impressive abilities, but don’t act overtly hostile, then we may well come to see them as very high status members of our tribe. Not powerful hostile outsiders.”

I deem that to be pretty hard a stretch, since our natural response to nasty tricks is with hostility and determination to get smarter/stronger, fast. Anyway, it’s clear from the history of colonialism on Earth that Robin’s proposed method was never, even once, used to dazzle and cow native peoples. The Portuguese did not conquer Indonesia by coating their ships in glitter and sailing quickly by, while shouting “ooga booga!” for 80 years without making actual contact. Instead, the classic approach used by conquerers back to Chinese and Persian and African dynasties – and especially European colonizers – was to co-opt and suborn the local tribe or nation’s top, leadership clade. Use power and wealth and blackmail and targeted assassinations to install your puppets and help them overcome local rivals. Superior aliens? No need for stunts if you have sufficient computational ability to learn our language and do those same things. And one can argue that recent US history is… well… compatible. (Especially the blackmail part!)

Yes, humans sometimes submit to foreign humans, who are very similar and can inter-mate. It is far less clear what it would take to get all humans to capitulate to very strange aliens, and aliens might fear that would change us too much for their purposes. After all, as they could probably just exterminate us, they must value something about what we are independent of them. 

Also, aliens might have wanted a simple robust strategy that could be approved well in advance by distant home officials reluctant to give much discretion or powers to local Earth representatives of limited trustworthiness and abilities. Revealing more info about themselves might lead us to hate them or find ways to resist them. 

g) Why haven’t successive U.S. administrations who hated each other used “the truth” as a political weapon against the other party? … 

By all reports, until now U.S. political administrations have not been trusted with any info at all about UFOs. 

No, my complaint, again, is that UFO nuttery is boring! Leaping to clutch the dumbest, most stereotypical and mystically primitive ‘theory,’ slathering on a voluptuous splatter of “I’m such a rebel” anti-authority pretentiousness, and then smacking in happy smugness like those French castle guards in Monty Python and the Holy Grail. 

That seems a bit unfair. If anything the most respected UFO researchers are reluctant to talk about any theories at all, for fear of losing respectability. 

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Seeing ANYTHING Other Than Huge-Civ Is Bad News

The great filter is whatever obstacles prevent simple dead matter from evolving into a civilization big and visible on astronomical scales. The fact that we see nothing big and visible in a huge universe says this filter must be large, and a key question is the size of the future filter: how much have we passed and how much remains ahead of us?

I’ve suggested that evidence of life elsewhere below our level makes the past filter look smaller, and thus our future filter larger. From which you might conclude that evidence of a civilization above our level is good news. That seems to be what  says here at Vox:

If (and I must stress that this is a quite unlikely “if”) UFO sightings on earth are actually evidence that an advanced alien civilization has developed a system of long-distance probes that it is using to monitor or contact humanity, then that would be an immensely hopeful sign in Great Filter terms. It would mean that at least one civilization has far surpassed humanity without encountering any insurmountable hurdles preventing its survival. (more)

But I don’t think that’s right. This would move the filter more to above their level, but below the level of becoming big and visible, without changing the size of the total filter. Which implies a larger future filter for us. In addition, any UFO aliens are likely here to actively impose a filter on us, i.e., to stop us from getting big and visible (or “grabby“).

So if UFOs as aliens is not good news, what would be good news re our future filter? Aside from detailed engineering and social calculations showing that we are in fact very close to becoming irreversibly grabby, the only good news I can imagine is actual concrete evidence of big visible aliens civilizations out there. Maybe we’ve misread their signatures somehow.

Looking out further and in more detail at the universe and still finding it dead suggests the total filter is larger, which is bad news. And finding any evidence of anything other than death suggests the filter is smaller up to the level of that finding, but doesn’t revise our estimate of the total filter. Which is bad news re our future. Thus a perhaps surprising conclusion: finding anything other than a big visible civilization out there is bad news re our future prospects for becoming big and visible.

Remember also: the SIA indexical prior (IMHO the reasonable choice) favors larger future filters. Beware the future filter!

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