[ExI] Interstellar FedEx.

[Anders Sandberg]

John Clark wrote:
> If you're concerned with interstellar distances then it's very hard to
> understand why you'd ever want to move matter around, moving
> information is so much quicker and more economical.

Actually, see the papers at
http://www.winlab.rutgers.edu/~crose/cgi-bin/cosmic4.html
They argue that in terms of bits/J moving encoded matter around is more
efficient. This hinges on the basic issue of how much energy is needed for
moving matter.

It is interesting to consider the marginal value of more matter if you are
already using every scrap of available matter for whatever your
supercivilization uses matter for (black hole cooling, entropy transport,
computronium, memory storage, heat death insurance). Robert Bradbury has
argued that due to comm lags and subjective time the value becomes
discounted to zero. Kardashev and some others seem to think the opposite,
and predicts expansion. Whether matter can be moved economically
influences this a lot. For example, black hole cooling is likely the best
way of keeping a superciv really cool if the cost of sending entropy to a
remote supermassive hole is low, but if the cost is high then radiative
cooling might be best.

> Well OK I exaggerate, you might want to send Von Neumann probes, but
> they are so small they wouldn't use much energy unless you were in a
> big hurry for then to get to their destination. Even at today's speeds
> you could send one to every star in the galaxy in less than 50 million
> years, and that's nothing.

Freitas old probe based on the Daedalus could do this, and I think he
assumed a 500 year replication time!

-- 
Anders Sandberg,
Future of Humanity Institute
Philosophy Faculty of Oxford University