Grabby Aliens: If We Weren’t Early, We Wouldn’t Exist

Humanity might not just be early to the universe… we may have to be early.

In this episode of Entropy Rising, we dive into the Grabby Aliens theory, one of the most fascinating solutions to the Fermi Paradox. The idea is simple but unsettling: if intelligent civilizations tend to expand across the stars, then any civilization born too late would never get the chance to exist at all.

We explore:
• Why expansion may be a natural outcome of evolution
• How civilizations could spread across the galaxy in only a few million years
• Whether Dyson swarms and megastructures should already be visible
• The link between Grabby Aliens and the anthropic principle
• Whether advanced civilizations would preserve primitive life or consume all available resources
• How this theory compares to ideas like the Zoo Hypothesis and rare life scenarios

If the universe is full of expansionist civilizations, then humanity may not just be one of the first civilizations.

We may be forced to be.

Transcript

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And I think a good analogy would be, like, what are the odds that two independent, not related intelligent species would evolve on the same planet at the same time? pretty unlikely because by the time that first species evolves, they're probably going to build tools and, take over the entire planet like humans did much, much faster than a second intelligent species, uh, could also co-evolve along with them, assuming that they weren't, you know, splitting from the same genetic tree. Hello, welcome to Entropy Rising, a podcast all about science and futurism. I'm your host Jacob, and joining me, of course, is the ever so wonderful co-host Lucas. Thank you so much, Jake. Yeah, I love, I love that you think I'm wonderful. Always. always. So for today's episode, we're diving into, uh, quite a fascinating theory. So this is one of the potential solutions to the Fermi paradox, the Fermi paradox of course being the question of, given how big and old the universe is, where is everyone else? Why are we here alone? So this theory or solution for the Fermi paradox is known as greedy aliens, and it effectively tries to explain that we're early in the uni- It effectively tries to argue that we are alone in the universe because we are one of the first civilizations to evolve. But it takes it a step further than that and says that not only are we the first civilization to evolve, but we must be the first civilization to evolve, or we wouldn't exist. So we're gonna dive into this, and I think it's gonna be a fascinating episode. I think so as well. that big distinction of giving us an idea that this has to be the reason why we are one of the first is what separates it from some other theories that also put us in the first. So I think it's gonna be really cool to dive in and, um, think a little bit deeper into that concept. Yeah. And I think that is something that's interesting about this one because there is always the possibility that we're the first because of random chance. There's always random chance and, and I've heard that argument before too. I am particularly drawn to this one because it's not just we're the first because we happen to be the first, which of course is perfectly possible. Mm-hmm. Uh, but it does go and take it a step further. So Lucas, would you like to jump in and explain the greedy aliens theory, or would you like me to? No, no. Yeah, I can jump in. So the way that the greedy aliens essentially works is that it is under the assumption that life, gets to a point to where they can go out into the stars will want to constantly expand, take over the resources and use them to, build into their civilization. And because of this, if that was true and life was able to evolve over the time that ours did, we would have already taken over all of the planets that could support life that were lesser, and you know, expand that and make it so that those resources couldn't be used and no other life would have formed anyways. Therefore, if we do exist- And greedy aliens is a probable solution to the Fermi paradox, then the only reason why we do exist is because we are one of the first Yeah, exactly. I think that's a key distinction for this theory is it basically argues that anyone who does exist necessarily must exist from a civilization that was among the first to exist in the universe. And the reason being is like what you said, is because if you assume every civilization is going to be expansionist, uh, and it doesn't have to be literally every civilization, but just most. If you assume that there's a tendency for civilizations to be expansionist, then once you get further into the history of the universe, then all of the possible new areas for life to evolve will already have been used up by these, quote-unquote, "greedy aliens". Mm-hmm. And I do wanna add a quick note here. It's called greedy aliens. It doesn't actually, like, mean that they're horrible, greedy, warmongering aliens, right? In this sense, what it means by greedy aliens is they're expansionist and they use the resources. They don't just sit on their planet and let the universe happen by them. They actually go out and expand their borders. And when we say conquer or use, uh, you know, the theory posits that they would expand until they ran into another species where they could cooperate and be very friendly, nice neighbors. It's just until they bump into another civilization, they're gonna continue to expand, uh, across the, what they discover to be dead universe. Yeah. it, goes by another name, I believe, is grabby aliens, right? Yeah, grabby aliens. Yeah. So, um, you know, I feel like that better explains it. And it's a good theory to think about because when you think of life itself, it is also grabby, right? life expands naturally, and especially as civilizations get more advanced. Like, we went from small pockets of civilizations to expanding across the entire planet. So it would only, you know, make sense that we would continue to do that as far as we could. And that's actually a really important thing that this theory also points out, is that, yes, the universe is very large, and it takes a long time to expand across the universe. However, this theory points out and it argues, I think rather successfully, that the time it would take for a upstart civilization to actually expand across their local area of space is much, much faster than the time it would take for another intelligent species to evolve from nothing. Uh, so when we think about it, we've talked about how you could potentially colonize the entire galaxy with something like von Neumann probes, uh, even not von Neumann probes, even just biological von Neumann probes, AKA, uh, us. Uh, we've talked about how you can do that in, uh, maybe half a million years. Uh, moving at, like 10% the speed of light. Half a million to about 2.5 million, depending on how, how fast you can move, whether it's 5% up to, like 50% the speed of light. But in terms of evolutionary timescales, that's pretty fast. And I think a good analogy would be, like, what are the odds that two independent, not related intelligent species would evolve on the same planet at the same time? pretty unlikely because by the time that first species evolves, they're probably going to build tools and, take over the entire planet like humans did much, much faster than a second intelligent species, uh, could also co-evolve along with them, assuming that they weren't, you know, splitting from the same genetic tree. That's obviously a different story and doesn't apply to universe wide, uh, life. Mm-hmm. it is a solid concept because of those reasons that, that we kind of see examples of it happening on a smaller scale being our planet. it definitely is something that's interesting to think about and that I, I feel could be very, very possible. Yeah, absolutely. So another thing to dive into with this, of course, and it links a lot with the anthropic principle. So the anthropic principle is effectively a type of bias you always have to keep in mind, or it's sometimes called the observer effect, which is that for an observer to exist to question their existence, uh, and reality around them, then they must, of course, exist an environment that supports their form of consciousness, of life, in whichever way that is. And the way that I often see this explained is sometimes people will look around the Earth and say, "Wow, what are the odds that this whole ecosystem works so flawlessly, so fluidly? There's the right amount of oxygen for human life. There's so many edible foods for human life. Uh, all these perfect conditions exist for human life. W- what are the odds of that?" And some people will use that to, to make an argument for the creator, uh, or what have you. But this is where the anthropic principle comes in because it also points out that the very fact that you exist to ask that question means that of course, the environment you find yourself existing in is going to support that, right? There could be hundreds of billions of barren planets, but you're only ever gonna find yourself existing on the, one planet out of that hundred of billions that could support your life. And the grabby aliens theory makes that same argument for us being first in the universe. Mm-hmm. Because it argues if you're not one of the first species to exist, then you never get to exist because all of the available, basically land, all the available real estate will have been consumed by these grabby aliens. So the odds of you being a, a new upstart civilization, young into your evolution, right, like we are, we're only, Humans have been smart for maybe 10,000 years. Mm-hmm. Pretty, pretty early on, on terms of, uh, evolutionary scales. So the... If you find yourself being early in your own history of your species, then you probably exist at the beginning, earlier stages of the universe before any other life has had a chance to expand. Yeah. And I mean, that's, that's a really cool concept to think about because it lets you kind of really settle into that thought that, wow, we may be one of the first civilizations because we are on this planet that offers these resources for life that are so plentiful, that if there truly were those grabby aliens, that they... this would be prime real estate, you know, for them to wanna move to, taking into account, thought that they are similar to us in structure and the way that they survive. Yeah, no, absolutely. And, and just the fact that we're so early into our own existence kind of also shows that too. It'd be one thing if we were hundreds of billions of years into humanity, and we still didn't find any aliens, then we could probably posit that it's not a case of us being early, but maybe a case of, uh, life just being extremely rare. But we are very early into humanity as it is, and so it's very likely that this is just, for whatever reason, the way the universe works out, we are now in the life-bearing age for our universe, and we're in the earlier stages of that. And so, you know, it's kinda fun to think about, right? This theory says that humanity might be first and, and if this theory's true, we might go on to be one of the, you know, huge stellar empires, uh, assuming that this theory is true and it's not just the case that life is extremely rare, which both can kinda go hand in hand. Yeah. So with, with that being said, there are a few different ways that this could play out. What are some of the assumptions that would be needed for this theory to exist? Yeah, no, that's completely fair. So there are obviously with any Fermi paradox solution, you need to look at the base assumptions that this theory makes and see if that actually works for a Fermi paradox solution. And I've kinda given this overlay a couple of times when we've talked about Fermi paradox solutions. Uh, but some of those assumptions rely on, for one, is this a universalizable assumption that you can make? And one of the universalizable assumptions that the grabby aliens theory needs is that life needs to be expansionist. Or what we should ask is that, is it the case that all life should be expansionist for this theory to work, and if it's not, does that break the theory? And so for that assumption, some people may disagree, uh, I actually think that's fine. I think that's a valid assumption that this theory can make for two reasons. Reason A is that at least on Earth and how we understand evolution to work, it seems like all life probably will be expansionist. It's just life is opportunistic, and by definition, it oftentimes tries to expand and find new niches to occupy and adapt to. And I don't think that that's gonna change on different planets. I really do think that's gonna be one of the underlying cases for life anywhere, uh, in the universe. And I, I feel like we can call that a universalizable in my opinion. I don't, I don't know what you think about that, Lucas. No, I mean, it, it makes sense, right? Now, of course, we are our own sample size- Of course our, our planet, but it's not just our civilization. You see the, like, like resource guarding, resource collection, expansion, territory guarding are present in, like hundreds of different species, so we can, of course, make that assumption unless we meet another civilization that changes that- Of course ... um, that, that we will want to or that our life will continue to do that just throughout the universe. And just thinking about it from going back to basics, just thinking about it in terms of, of life existing in general, any form of life that's more expansionist than the life around it is probably gonna do better in, in Darwin's game of evolution because they're better gonna be able to expand out, extract more resources, and out-compete, uh, less expansionist f- uh, versions of life. So you would imagine any planet that goes through natural selection is going to tend toward favoring ex-expansionism. So I do genuinely believe that's gonna be very common, and that's, that's where I'm basing my assumptions on, that this is very likely gonna be a universalizable truth. Yeah. I mean, it would, it would actually go against all of the, the facts that we have on life so far to say that it wouldn't. Yeah, exactly. Now, of course, once you start talking about advanced civilizations, things get a little different because we can kind of separate ourselves from biology a little bit. We're thinking, we're rational, a- and there's always the possibility that species may act differently than just basic biological, you know- bacteria, right? Uh, so this kind of brings me onto the second point of is this a valid assumption, which is point number two. Even if it's not universalizable, even if it's not the case that all life expands, that's fine. You really just need some life to be expansionist to have this theory work out. It, it only takes... depends, of course, on the, the density of, of life and intelligent life in the universe, but even if one in 10 species are actually expansionist and go out and, and expand, that's fine for this theory. That doesn't break it at all. You just need some life to go out and expand, and if that's the case, then this grabby aliens theory works as long as you don't f- find yourself in a really rare situation where no life expands. And, and that's the part where I would say it starts to break this rule of universalizability because in order for this theory to not be true, it would basically need to be the case that no life goes out and expands, and that is, of course, possible. Either life's extremely rare, uh, so you only get, like, one life form in a galaxy cluster. In which case, even if that life's expansionist, it, it'll likely never encounter other life. no, I mean, that, it definitely makes sense, but it's just, uh, it just seems more unlikely. And like, just like if you were saying, if only one is expanding, then tho- those other planets could even be left alone, but the aliens would branch out and they would take everything else. But even us without being an expanding civilization, we already have the intention to do so. So it's like that sample size being 100 just makes that more and more plausible. I guess another assumption this also brings up is can we actually expand and explore the galaxy? I know that's very related to the first point of would you want to. Mm-hmm. But it is important to consider could you. And arguably, that's kind of what this whole podcast is about, how you would go and move about the stars, and I see no reason why you can't go and colonize the universe. I, I know I already mentioned von Neumann probes, but that's a great example. We already have an idea with something like Project Sl- uh, Slingshot, where we could potentially send a probe to our nearest star, Alpha Centauri, fairly quickly just through some, uh, pusher lasers and solar cells. So it's not an impossible thing to do. To expand into the universe. Can you make self-replicating probes? Sure, why not? Uh, because biology can do it, kind of to me tells us that you can do it with technology as well. You can design cells, you can design, uh, biological biomechanical beings if you really needed to. But there's no reason to think that you couldn't design self-replicating probes as well. And even if you couldn't design self-replicating probes, uh, the fact that you can, get to the same end with biology. You know, we basically are self-replicating von Neumann probes. I know I've read some science fiction that involves that, um, that talks about that idea, being- Mm-hmm that life was started on the planet and called out the fact that, uh, that's kinda how biology, uh, behaves. And so we know that it's, it's perfectly possible to, to reach other stars. It, it becomes questionable, and, and this is fair, if you could build, like interstellar colony ships and send humans to other stars, but I genuinely think you could. And you can also get around that if you really want to. I, I know Revelation Space touches on it, and granted it doesn't work out well in that book, but you can also send ships of, like embryos for example, 'cause those are much smaller. You don't need to have all the same life support. Grow them up with something like an artificial womb, and then use that as a way to expand the galaxy. In Revelation Space they all go crazy because it turns out you need parents, which fair enough. But- ... um, that's just one of the examples of how you could do this. And I do think you could build a ship that actually contain humans and get them to another star as well. Oh, yeah. Of course. I mean, we've touched on that topic before. And, um, like actually going across our entire galaxy and colonizing these planets, especially if we're using, uh, like von Neumann probes to do it that are hyper-efficient, are able to, to colonize and move on to a new planet, Drop people off, or whatever we are at that point. Drop us off and then keep going. we could colonize the entire galaxy, what, in like 150 million years? Oh, no, no, like, uh, two and a half million years. Two and a half million years. Now- I think that's assuming 10% the speed of light. Okay. So now think about just, like, how long, evolution has taken for things to get to a point. Now, again, grabby aliens doesn't have to be just one. It could... It would be all the civilizations that evolved to an expanding point, Around the same time. And, and, There, there's different borders could be set up. But it's just the assumption that you are one of the first. So you don't even need to have the whole galaxy assuming that on the other side of the Milky Way there's another civilization similar to us. You know, we could split it in half. Uh, but- And that's effectively the argument, is you continue to expand until you bump into other civilizations. Right. So you, you essentially expand, you make those borders. But We would be expanding so rapidly compared to evolution that, we would essentially take everything, that would be useful. Yeah, exactly. If you are colonizing and terraforming planets as you cross them- Then the odds of other life forming and, and developing intelligence is, this theory argues, zero. Although that's another assumption that we can evaluate too. Would it be the case that because a civilization is expanding, that it necessarily means that new civilizations couldn't start within their borders? And that's, that, that one I question, because I could definitely see cases where intelligent species like ourselves, decide not to do that. For example, number one is that we've made the argument so many times on this show, it almost gets gets old, uh, but we don't think living on planets is necessarily the best way to go about things. we think that it's very possible you may favor living in orbital habitats, things like O'Neill cylinders, McKendree cylinders, uh, what have you. And in this case, planets suddenly become a little less valuable than I think this theory posits. Mm-hmm. And so it's very possible that as you're expanding across the universe, if you discover a planet that already has life on it, not intelligent life, but just life in general, that you may decide to quarantine this planet, use it for scientific study, uh, but allow it to go through its own natural course. And I think especially if that life is fairly rare, you would, you might treat these planets as like jewels a- and not jump on them. And another thing I wanna point out, because I, I know a critique to that might be, okay, especially if life is rare, if we come across a biosphere, aren't we gonna wanna jump into that and use it? Because what are the odds of finding planets that can support our life? But just because you find a biosphere doesn't mean that that's gonna be able to support our kind of life. It could work on very different ratios of gases, even just different levels of oxygen could make it very hard for us to exist, could be different temperatures, and it could actually be, uh, harder to adapt a biosphere to support our life than starting with a sterile planet. so I don't necessarily know if that's true, that because a civilization is grabby, quote-unquote, and expansionist, that it wouldn't preserve planets that are harboring life and allow them to go through their own course. No, I mean, it, it definitely could. but At, at what point does that civilization become a- advanced enough to where, like, do we allow them to get to the point to where they expand out into their solar system or to where they can even observe us? Because if the grabby aliens theory is, we, we are one of the first because if we weren't, then we wouldn't exist- Exactly ... at the point that we are now. And that's why that would break the theory if the grabby aliens don't just automatically occupy planets and prevent life from forming on them or intelligent life from evolving on them. I mean, they could, Like, let's say they, they could allow life, life to get to the point of how we were maybe 1,000 years ago. Because at that point, you know, we didn't really have the technology to even be able to observe them. But with how we are now, it's safe to assume that if they had O'Neill cylinders in our solar system, we would be aware of them. Yes. But they, but they don't. The whole argument for the Fermi paradox is we should be able to detect things like Dyson swarms in the universe, and we could detect those from a very long way away. Uh, so obviously as far as we can tell right now, that's the ca- we don't see that. We think we're one of the first. But if we were one of these upstart civilizations in a quarantined planet, then that would be something different. And what we really would have to do is explore this in a whole other episode on the zoo hypothesis, 'cause that's effectively what this is. but I, I do wanna call out that one assumption on this grabby aliens theory, and it's always kinda nagged at me, is that I don't necessarily think you can just call it true that an advanced civilization would make it impossible for intelligent life to form on planets that are within its boundaries. Yeah. it definitely could be true, and bringing in the zoo hypothesis is, is great because again, that is another thing that we do here on, on Earth. So going off of those assumptions, if we do find something like life, and, we've talked about this a lot before, but living off planet is gonna be way more efficient, um, than trying to, survive on a planet. then I don't see a reason why we wouldn't wanna preserve life and just, just for observation, scientific study, or just, like, some kind of futuristic entertainment for, for public masses to go and visit all these different creatures. Yeah, absolutely. Now of course that's assuming you find a planet that already has a biosphere. It is worth pointing out even cold, dead rocks could eventually harbor life down the road, so that's kinda the argument for the grabby aliens theory is even if they're benevolent, uh, they may deny opportunities for life down the road just because they're taking these resources of planets that would eventually harbor life. Yeah. Uh, so I guess that is also kind of playing into it too is if you only were to allow planets that already have a biosphere to exist, then you still might be denying a bunch of opportunities. And depending on how rare life is, it could be the case that, uh, you still kinda play into it. But again, I think that we're gonna have to do an episode on the zoo hypothesis and dive into that a little deeper, 'cause that could turn into its whole other episode, and I do think it's a fascinating one to think about. It is. And it also kind of draws us into an assumption on the Fermi paradox as a whole, which of course this being a solution to is also something to consider, which is could we necessarily detect advanced alien civilizations? And essentially the assumption there is that advanced civilizations are gonna build massive solar collecting things like Dyson swarms, which is something we could detect from a very far distance even with our current technology. In fact, we thought we observed one with something like Tabby Star, which ended up just being a star that was occluded by some dust. Uh, but the fact that we could even detect that, it kinda gives you an idea of why we assume we can detect Dyson swarms. Yeah. I see some people, they think that, the aliens would maybe hide that technology from us, um, by some kind of cloaking or something like that to where we couldn't observe it. But I, I think that it's a little bit egotistical to think that they would even care that m- building those structures, being broadcasted to a civilization, uh, so low beneath them as ours would be, that they would even be concerned with something like that. Yeah. It's always tricky to say, and it's, it's really tricky to try to guess the motivations of an alien intelligence. Mm-hmm. Um, but I could see it going either way. But I agree with you. W- it could be the case they just don't care, and when you find yourself able to detect them, maybe they swing down and say hi. Uh, but yeah, there's all kinds of ways that you could get around that, so who knows? Uh, but I do like that the, this theory posits that we could be one of the first or... It actually goes even further. It doesn't just say that we could be one of the first. It argues that we are one of the first- Mm-hmm and we must be one of the first. Yeah, I agree. That's why I think that this one is really cool to think about because by its nature, we would have to be. And that is kind of... You know, it's lonely, but it's exciting. Yeah, I like the idea we could be some galaxy-spanning empire, and it's kind of fun to think about it in this way. And it does fit with my model of how I expect humanity to function. I think we're gonna continue to expand out as much as we can and, and take over any resources we can. So o- on that sense, I kind of agree with the grabby aliens theory. And I guess my main critique with it and the main thing that could counter it and make it not true, I mean, there's a bunch of other Fermi paradox solutions that could make it not true, but I guess my main critique with it is that it kinda breaks if you just believe that life is extremely rare. Mm-hmm. That's a perfectly valid alternative and kinda breaks this theory if, uh, if that is the case. so a- and that is something I could also see, 'cause I, I still think that in my head and, like, when I'm, like, ranking which Fermi paradox solutions do I think are actually true, I do think the odds of life being just incredibly rare, maybe again instead of thinking it happens a couple of times in a galaxy, it might only happen a couple of times in a galaxy cluster. Maybe we're the only intelligent life, uh, you know, within a couple hundred million light years of, Earth. That also, uh, to me just seems like it's very possible. Yeah, no. I mean, uh, it's, it's like you said in the beginning of the episode, random chance is always a possibility, and there is a random chance that we, that we are the first civilization. And if that's true, then, you know, there's, like, the grabby aliens, like, other civilizations expanding really has nothing to do with that. it is easier to grab onto grabby aliens, no, no pun intended, because, They give you this, this definite, excuse as to why we would be here. Yeah, no, absolutely. With that, is there any other assumptions you can think of that this theory needs that should be evaluated or that we should underline? No, no, I, I, I think, I think that's about it. Yeah, so this was a bit of a shorter episode, but it's an interesting topic to touch on, and, uh, worth evaluating some of those assumptions. So I hope you all enjoyed it, and I think this sparked us and inspired us to dive into the zoo hypothesis as a solution to the Fermi paradox for next week. So if you enjoyed the Fermi paradox and you wanna hear more about it, check out our next episode when that's released. Thank you all for joining. Thank you, guys. Bye-bye. Bye.