[ExI] Physical limits of electromagnetic launchers

[Anders Sandberg]

Just a quick question to the list, since I suspect there are wise beings 
here who might have good insights:

What are the physical limits to launching long-range relativistic 
payloads with electromagnetic launchers?

Let us ignore the energy and material access constraints, we have a 
Dyson sphere and fairly mature nanotechnology. Obviously there is going 
to be some limit on acceleration tolerance of the payload, so based on 
that one can make longer launch tubes for slower acceleration.

It seems to me that the main limit is how strongly the electromagnetic 
field can couple to the launched package, and the heating effects.

Anybody has any thoughts on this?

(And don't worry, it is not intended as a relativistic kill weapon. It 
is for science! And maybe spamming the universe)

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