Random Fermi Paradox solution of the day:

Nobody goes into space and colonizes the galaxy because only Moon Nazis want to do that, and after experiencing a few dozen genocides all sapient species learn the safest thing to do when you see a Moon Nazi is to murder them immediately, it's the only way to avoid the genocides.

@cstross Okay - what about a group that takes as given that neither they nor their descendants will be alive aim to establish a foundation/group/club/whatever that can wants to *eventually* build an ark to reach Proxima Centauri at it's closest approach in about 26,000 years.

The ideals, goals, ambition, institutional methods established by the "tree planting" generations just pitching designs and funding research, etc.

Presumably non-nazis.

Basically Long Now foundation + Centauri Dreams.

@stevenaleach You're describing a goal we only have—at best—two social structures capable of achieving: a religion, or a royal family. Both of these have undesirable failure modes. (Most human social structures disintegrate or lose track of their purpose over roughly the same duration as a human life expectancy.)
@cstross Yes! And I doubt it could be solved but it's fun to think about. Say a group wants to build a plasma sail vessel -- solar wind speed, so over 4k years to A.C now, shorter leaving at some point closer to A.C's closest approach. For slow enough of a ship, there's some ideal departure date many thousands of years from now to minimize the trip time. And that's an epoch cool timescale to think about that puts the epoch scale of getting to the nearest star into perspective.

@cstross And it turns the story into two engineering problems, both epoch: engineering multi-thousand year institutions based on an idea and that institution having the goal of building some mega-structure that has to be self-contained and survive a similar timescale and support a bottle civilization over a similar number of generations rivaling the time since the dawn of agriculture for both phases.

See - "moon nazis" wouldn't be into any of that or contribute thinking to it. Maybe.. ?

@stevenaleach @cstross
But nobody can express a practical and realistic reason why we should try to get to Proxima Centauri. Any motivation to try to do it is profoundly irrational, so although you might initially avoid actual Moon nazis, you still have to put enormous resources in the hands of people you *can't trust* to act in the interests of humanity, and hold it together for 1000s of years without Moon nazis or The Lunar Inquisition taking over at any future point.

@stevenaleach @cstross
More importantly, if your civilization could engineer that feat of scope, energy transmission, and containment, why would anyone even get off the ship at the destination?

Or more importantly, why leave your solar system, or world at all if you have that kind of containment.