Recently, I was reading some arguments about Fermi paradox and aliens and so on; also there was an opinion among the lines of "humans are monsters and any sane civilization avoids them, that's why Galactic Zoo". As implausible as it is, but I've found one more or less sane scenario where it might be true.

Assume that intelligence doesn't always imply consciousness, and assume that evolution processes are more likely to yield intelligent, but unconscious life forms, rather than intelligent and conscious. For example, if consciousness is resource-consuming and otherwise almost useless (as in Blindsight).

Now imagine that all the alien species evolved without consciousness. Being an important coordination tool, their moral system takes that into account -- it relies on a trait that they have -- intelligence, rather than consciousness. For example, they consider destroying anything capable of performing complex computations immoral.

Then human morality system would be completely blind to them. Killing such an alien would be no more immoral, then, say, recycling a computer. So, for these aliens, human race would be indeed monstrous.

The aliens consider extermination of an entire civilization immoral, since that would imply destroying a few billions of devices, capable of performing complex enough computations. So they decide to use their advanced technology to render their civilizations invisible for human scientists.

Not entirely relevant to the main issues of lesswrong, but possibly still of interest: my talk entitled "von Neumann probes and Dyson spheres: what exploratory engineering can tell us about the Fermi paradox".

Abstract:  The Fermi paradox is the contrast between the high estimate of the likelihood of extraterritorial civilizations, and the lack of visible evidence of them. But what sort of evidence should we expect to see? This is what exploratory engineering can tell us, giving us estimates of what kind of cosmic structures are plausibly constructable by advanced civilizations, and what traces they would leave. Based on our current knowledge, it seems that it would be easy for such a civilization to rapidly occupy vast swathes of the universe in a visible fashion. There are game-theoretic reasons to suppose that they would do so. This leads to a worsening of the Fermi paradox, reducing the likelihood of "advanced but unseen" civilizations, even in other galaxies.

The slides from the talk can be found here (thanks, Luke!).

A recent post about the Fermi paradox left me wondering about relative difficulties of getting into space, though I don't think it affects those specific arguments.

People establishing a presence in space is difficult but at least plausible-- I'm talking about biological people as we are now, and being able to live and reproduce indefinitely without returning to Earth.

It would be easier if we were less massive, or our planet was less massive, or if we were more radiation resistant. It would be harder if these qualities were reversed, or if we needed a much denser atmosphere.There might come a point where it just isn't feasible for a species to get itself off its planet.

Is there any reasonable speculation about where we are likely to be on the ease-of-getting-into-space spectrum?