There are lots of hypotheses, but this is one of my gut feelings for why there are no aliens in view. It's hard to escape your local solar system.

When will we need more resources than exist here? We'll be mining the sun to run future simulations. Do we need more compute? Seems like we'll just stay inside.

Most life is probably similarly bound up to their origin. That and life is hard by many, many, many hard steps. Earth life is nearly 30% the age of the universe and it took us this long to get here.

It'd be near impossible for aquatic life to have an industrial revolution without aqueous chemistry control. Can't do that when you're stuck inside water. It's also hard to evolve reasoning when you can't see far ahead. Little evolutionary pressure on reasoning over time and distance.

And it's hard to leave water. You need to evolve new eyes and lungs to live on land. And then you need an energy source like O2, which tends not to stick around.

So many reasons.

The distances of space are certainly one holding us back now.

One thing I keep wondering, though, is whether “life” is tied more to the particular chemistry and environment it uses or to its patterns (the abstract information structure that can, in principle, be re-instantiated on different substrates).

If it’s the patterns that matter, do you think it’s actually impossible for those patterns to be transmitted across interstellar distances? Just like a cup of ocean water is packed with DNA, it’s at least conceivable that what we call “cosmic background noise” could, in principle, hide extremely compressed life-patterns that only an advanced civilization could recognize and reconstruct back into something we’d meaningfully call “alive.” And of course, the more efficiently you code that information, the more it statistically has to look like random noise.

Not saying this is likely -- just that if the essence of life is informational rather than chemical, "traveling" could look very different for any life that is suitably advanced.

The resource thing always gets me. More ideas of things like dyson sphere's. Where does the material from them come from?