> The dark forest hypothesis assumes that it's easy to travel between stars, so interstellar conquests are possible. But it doesn't seem to be the case.

Wrong. Dark Forest isn't about conquest, it's about preemptive strikes.

The Dark Forest hypothesis assumes that travel between stars is hard - more importantly, that even communications at those distances is hard - specifically, that it takes a long time, which prevents building trust. This, combined with one other assumption: that technological progress makes unpredictable jumps ahead, makes the conclusion fall out straight from basic game theory.

So per the Dark Forest hypothesis, if you spot a primitive agrarian society sending a "hello" to you with smoke signals, you're better off lobbing a nuke at them in response - because otherwise, should you send a friendly "hello back" instead, you may discover that while that message was in flight, they underwent a triple industrial revolution, and shot a magic proton bomb at you.

Why would they do that, you ask? Because from their POV, at any moment you can have a sudden technological breakthrough and start dragging black holes at them or whatever. Point being, it's best for them to get rid of you, while they still can.

(People get too fixated on the forest metaphor XOR the sci-fi parts, but it's really neither; the second book of the trilogy pretty much spelled out the whole rationale like a math textbook, in case anyone missed it after half of first book making analogies to it with ants and history of modern China and such.)

(ETA: what's the justification for "sudden technological jumps" assumption? History. Humanity had ~all the ingredients for the industrial revolution for centuries, and it's not clear why it happened when it did, and not a century or two earlier (or later). Then it happened, but the outcome wasn't "evenly distributed". Then the 20th century saw several large nations jumping all the way from pre-industrial agrarian societies to post-industrial peer superpowers, in a span of merely a few decades. The author writes extensively about living through that transition in the first book.)

That sounds like an invisible malevolent force trying to destroy us, himm, sounds familiar :).

>>There are no material goods that can justify the material and energetic expense of any interstellar travel.

Material, no. but we know with absolute certainty that Earth will stop being habitable for humans at some point. So assuming any intelligent race, human descendent or otherwise, still exists on this planet, it will have to eventually move. It's just pure luck that we evolved when we did. But there are valid reasons for interstellar travel(other than you know, pure curiosity).

That's why I never understood sci Fi nerds obsession with outer space, as opposed to inner space. Humans sit about half way between the biggest and smallest things in the universe. Instead of exploring the cosmos, which takes tons of energy and is almost entirely empty, we could be exploring the space between atoms and building worlds without our own world. It is also almost entirely empty, but the energy costs to construct anything would be close to zero.

They already let an illegal alien buy the last election.