[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: starship-design: Black holes and the rocket equation



Steve VanDevender wrote:
> 
> Who needs to guess?  Black holes can be any size you want.  Unless a
> successful quantum gravity theory puts a minimum limit on black hole
> size based on the size of a quantum of space, there's no size minimum
> and hence no mass minimum,

Correct. I recommend to all interested Kip Thorne's book "Black Holes
and Time Warps: Einstein's outrageous legacy". It explains everything
(almost) about black holes. Also for some speculation on them for
propulsion, "Cosmic Wormholes" by Paul Halpern. Black holes are a really
speculative thing (in starship engineering). I'm not saying we can't
speculate on using them, but we'd have to make some (!) estimates if we
intend to use them for SSD. It's up to everyone.
> 
> If I remember correctly, R = G * M/(2 * c^2): R = Schwarzchild radius, M
> = mass, G = gravitational constant, c = speed of light.


This is the closest estimate we can get. Remember: A black hole can have
a measurable circumference that is precis, but a diameter that does not
equal 4pi. One of natures little tricks.
 
> Small black holes also make better thrusters; they evaporate much, much
> faster.  Any stellar-sized black hole doesn't evaporate quickly enough
> to be useful for that purpose.

Hopefully the don't explode violently! (And I mean one POWERFUL
explosion)

Kyle Mcallister