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When I first read the Three Body Problem series, a lot of it, like the Dark Forest theory etc seemed a bit off, and I tried hard to retcon some of the assumptions being made about physics and biology etc into something that actually made sense.

Then I read Ball Lightning, and had the revelation of "Oh shit, this dude actually has zero comprehension of how physics works". Then I felt silly for all the energy I spent trying to make any of it make sense. All his books are a ton of fun, and lots of imaginative concepts, but it really is all just for fun, and not really realistic at all. The whole 12 dimensional deflation concept shook me for months, and Dark Forest Theory is a really cool concept, and totally valid in certain environments, but almost certainly not in our galaxy at this point in time.

> For as awesome as Earth is, it doesn't have any unobtainium some hyper advanced species couldn't find elsewhere.

Yeah, I'd imagine that even if a hyper-advanced civilization did stop by, they'd probably just harvest a bunch of hydrogen from Jupiter to refuel their spacecraft, and be on their way. Earth has some of the least interesting resources in the solar system.

Most importantly, environments with plentiful resources that explode with life tend to develop a robust ecosystem of symbiosis and mutual dependence. The only time "Dark Forest" type ecosystems emerge is when resources are insanely restrictive, like deserts etc. As far as we can tell, our galaxy is teeming with resources that no one has really started mining at scale. Even if we did bump into some other expanding civilization, there's approximately zero chance of anyone getting boxed into a corner that would lead to conflict. We would just keep expanding in some other direction.

What if they don't "hop on" and "visit"?

For example, humans seem to be at a point where corporations are trying to automate everything - what if some alien civilization figured out automation was the way to go as far as colonization and what if they figured this out say, 20 million years ago and so didn't care if it took a million or 2 or 5 million years to "get here" via some automation that is beyond our ability as humans to perceive?

Then by even some very conservative assumptions they could extract all the obtainable resources of the entire galaxy within a few tens of millions of years. We should expect to see nothing--not stars, not galaxies. Nothing but a soft infrared background radiation from the back side of Dyson swarms.

Why? You're ASSUMING such an alien civilization's goals would be in line with countless strategy games.

What if millions of years of advancement wound up leading to very, very different goals for colonization than what we're used to based on pretty much nothing else other than fairly recent (by comparison) human history?

What if, for example, if you're a civilization that's been around for millions of years, your goals are no longer to "extract base resources" like in "Starcraft" ... but rather to play a sort of "Sims" game where you guide the development of life on various planets and "extract" research data – or simply sit back and enjoy the show?

Or what if they have an advanced Ai they're testing and want to see if life on colonized planets turned out like the Ai said it would, and if so – to what extent?

In that case, the "resource to be extracted" wouldn't be physical as much as knowledge and possible entertainment.

Then you could extract research data from quintillions more civilizations simply by directing stellar light instead of simply heating the universe by a few micro kelvin.

Dark matter. I know we don't see it in infrared, but maybe there is a way to block even that with some physics we do not understand.

Doesn’t work out. Beyond the already mentioned fact that true zero emissions is physically impossible, dark matter is seemingly spread throughout the cosmos, not clumped together where light matter isn’t. If this were the solution they would take over an entire two thirds of the galaxy, not diffusely consume two thirds equally across all space and time.

You make good points. But maybe situation would be different - they could be a paranoid race (maybe even for good reasons, based on previous experiences), or race looking forward beyond next few thousand years. Planning/doing colonization of entire galaxy, at massive scale (ie insect-like).

Resources are finite, room is also finite and other galaxies are ridiculously far for sub-light expansion. When cold hard logic is applied, even great ally will eventually turn into competing party, just a question of time.

Its true that in that case Earth would be probably preemptively wiped out long ago since life markers are here for billions of years. Its fun mental exercise, just highlighting how we don't really have a clue, just wishes/fears and some (doubtful) statistical projections like Drake equation.

Of course that's what a giant robot would want us to believe...

But seriously great writeup, thanks. I think the two convincing pieces that are also missing is the economic theory of unequal exchange which shows that even when one party is better than the other by every metric (technology, population, resources, etc.), there's still advantage to trade. And the other is the extreme waste of natural resources the dark forest species permits to occur under its watch. All those trillions of stars bleeding negentropy into the wastes...

For the record in the novel The Dark Forest, most aliens don’t actually get in space ships and visit, they hurl relativistic projectiles at the sun and blow it up. The reasoning being something like the prisoner’s dilemma (in space!).

Also I do think it’s too early to call it as safe: just because something has not happened yet does not mean it won’t happen, or “absence of evidence is not evidence of absence”

I don't disagree with your take on the dark forest idea, but as an aside, what if the "unobtainium" is us? Or the biodiversity of the planet? If aliens show up and decide to make us a zoo or a reservation, or an experiment that could be just as unpleasant.

Physics is unforgiving and space is big. A species that would want to put us in a zoo would need to expend vast amounts of energy (and time) to get here, slow down, grab someone, then get back home, slow down, and then finally drop them off. They would have to plan this mission not knowing our physiology, morphology, or biology. It's difficult to even imagine a situation where the value proposition of that is worthwhile.

Scientific curiosity has a value but the effort involved would be Brobdingnagian.

If we assume some species decides to undertake such an endeavor and has the capability of doing so, there's nothing we can do about it. This is why the dark forest idea is so dumb, we can't not broadcast ourselves. We also can't change the minds of some unknowable alien species that decides to come over and put us in a zoo. We can take issue when they actually arrive but that's about it. It's not something that's worth worrying much about all things considered.

I'm confused; every explanation of Dark Forest Theory I have read has asserted that aliens do not want to visit us, and would not try and invade our planet? (Maybe I just don't understand Dark Forest theory?)

The dark forest theory posits that you shouldn't advertise your existence because you're in a dark forest surrounded by competitors for limited resources. The idea being that a competitor will want to come destroy you when they find you since you're competing for the same limited resources.

It's dumb because like I said Earth's biomarkers are already broadcasting out in space and have been for millions of years. Also space is stupidly large. It's a bit absurd to assume a species capable of interstellar travel on a scale to send invasion fleets could develop that technology but not the technology to fully exploit their home solar system and adjust their own growth to be sustainable.

Even if such an unlikely species existed, they're already on their way. Their need for resources would be so great they'll send an invasion fleet the moment they find a world with biomarkers or whatever it is they want. They're not going to wait for radio signals or even industrial markers. So the dark forest theory as some policy to not develop technologies is extra dumb.

This isn't how DFT was explained to me. The differentiating points are:

1. Aliens would kill us because they cannot determine if we are an existential threat. If they assume we are friendly and we are not, they are dead. It isn't about resources, it is about destroying your enemies before they evolve the capability to hurt you. There is no good way to monitor or communicate with a civilization more than a couple dozen light years away, physics doesn't allow for it. By the time your message gets there the entire government, culture, etc of the planet has probably changed.

2. They would use long range missiles (e.g. an asteroid going sufficiently fast) to wipe out the planet, not an invasion fleet. This means that they don't have to have the capability to travel in deep space, just to throw big rocks.

3. This is all predicated on a few assumptions: that no aliens are living close(r than 400LY) to us, developing the capability to fling rocks at a star or planet isn't extremely difficult, and that once the big rock is in motion, there is no good way to defend yourself against it (except sniping it with another big rock, but that's probably magnitudes harder than hitting a planet).

I don't know enough about biology to dispute the thing about biomarkers, but that would put a huge dent in DFT. And I agree using it to make policy decisions is dumb.