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0 pointsqayxc3y ago0 comments

The very concept of a "Galactic Empire" is flawed as soon as you take scale and spacetime into account. The first major obstacle to the concept is distance. It'd take centuries to get even to the nearest off-world colonies and even simple things such as common time keeping become a challenge.

Communication basically breaks down completely once you get to distances beyond just a few light years: consider a "small" interstellar kingdom within a 100 ly radius. The central world will always necessarily be 100 years (in terms of just time) away from the outer worlds. Something happens on the outer rim, the central world won't be able to know about it until 100 years after the fact.

So in essence, every world that's more than a few (e.g. less than 5 or so) light years away is practically isolated from the rest - both logistically and from a communications perspective. It's very hard to come up with any way of describing such a scattered collection of islands as one coherent civilisation.

Another issue is the colonisation process itself. It's virtually impossible to find a nearby 1:1 copy of a world that matches the point of origin of the civilisation. Therefore, terraforming (a lengthy and resource intensive process) or genetic modification would be required. The latter will occur naturally anyway, since some physical attributes of the target world simply cannot be changed without god-like powers (e.g. orbital parameters and gravitation). This means you'd end up with sub-species pretty quickly that won't share the exact same biology and probably have a very divergent culture as well due to being so isolated.

You'd have to come up with some really strong arguments as to how and why - given these circumstances - even "just" interstellar civilisations should be possible in the first place.

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Nomentatus3y ago

Because it's cheap. You only pay once for one small vehicle [1], and its reproduction at the first destination sets off the whole rest of the process. I wouldn't advise sticking to gravity wells. Or even bothering with them. Subspecies and cultural divergence can be seen as a solution, leading to more innovation that can be shared at the speed of light.

[1] https://www.cambridge.org/core/journals/international-journa...

qayxcOP3y ago

But micro-scale von-Neumann probes wouldn't be building civilisations either - they'd be l'art pour l'art - building more Dyson Swarms for the sake of building more Dyson Swarms. The paper also only considers microscopic probes "invading" HII regions (i.e. hydrogen-rich star forming regions), not colonising space.

By "cheap" you also left out the author's assumption that "the propulsion system will require a tiny fraction of the total gained mass to convert into energy, which we assume could not be a problem for a Type-II civilization."

So they already start with a Type II civilisation that basically dismantled part of their planetary system to reach that state in order to... build probes that construct more Dyson Swarms? Still doesn't sound like a very compelling argument to me.

The paper also doesn't deal with the actual expansion aspect - only with the detectability of micro probes moving through- and replicating within star forming regions, i.e. not places you'd actually want to colonise - neither inside or outside of gravity wells.

> Subspecies and cultural divergence can be seen as a solution, leading to more innovation that can be shared at the speed of light.

You seem to greatly underestimate the vastness of space. Even a tiny (by Fermi-Paradox standards) interstellar realm would have worlds hundreds of lightyears apart. There's not much use in sharing "innovations" if they arrive after 500 years - not much innovation left after such a long time (unless you assume that one side stops innovating entirely for some weird reason, yet keeps listening for signals), plus it'd become increasingly harder to even keep a common cultural understanding given the temporal and spatial distances. Language changes over time, for example.

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