Re: (TFT) Space travel - galaxy sized dyson spheres.

[Mark Tapley <mtapley@swri.edu>]

At 3:44 -0500 12/10/11, Jay wrote:
> A solar mass only bends light to a few milliarcseconds nei?

..No. Nei. Whatever.

It depends, completely, on how close the light passes to the mass. If 
the solar mass is swelled up to 1.4E6 km diameter (like ours is) by 
internally-generated heat, then yes, because the light can't get 
closer than about 7E6 km to the center of mass without getting 
obstructed.

If the same mass is allowed to cool and contract into a "white 
dwarf", probably a good fraction of a degree, since the white dwarf 
will have a *much* smaller radius, and the light can pass closer to 
it.

If the same mass is allowed to form a neutron star (ie the electron 
shells collapse, so the mass is jammed up nucleus to nucleus), radius 
goes down to 12 km or so. In that case, light is deflected probably 
tens of degrees. (Current theory says neutron stars actually need 1.3 
solar masses to form, fwiw.)

http://en.wikipedia.org/wiki/Neutron_star

Finally, if you can crunch the mass of the sun just a bit smaller 
than a neutron star, it becomes a black hole. Then the light gets 
bent arbitrarily far. I suppose you could think of it spiralling down 
forever, but I'm not sure that's a fair depiction of the space-time 
around a singularity....

At 3:44 -0500 12/10/11, Jay wrote:
> By that measure Galactus the Devourer of Worlds is a baby when it
> comes to resource consumption.
> It would be well over 450 billion solar masses to close the "circle"
> and just how big would that circumference be?

..again, it's all about the density.

http://en.wikipedia.org/wiki/Micro_black_hole

21 micrograms appears to be enough. But it would be a pretty small 
black hole, and could only bend light over a pretty small area.

Hm, it appears "Halo" had this idea before me, but a whole tank full 
of evaporating black holes, with different masses so that one will 
boil off every second or so, would be a pretty compact energy source. 
Of course, not just every filling station is going to be able to 
"fill 'er up"...

At 3:44 -0500 12/10/11, Jay wrote:
> lot's

lots. For some reason I'm annoyed by incorrect placement of apostrophes...

At 3:44 -0500 12/10/11, Jay wrote:
> Anyway, I don't think a "shell" can NOT spin.

I suppose. Ringworld was easier to figure out in this context. If it 
spins, what holds the poles up? If it is strong enough to hold up the 
poles, isn't it therefore strong enough to hold up the whole thing, 
even not spinning?

At 3:44 -0500 12/10/11, Jay wrote:
> IMHO 'apprentice' in TFT means "human(oid) ST battery".

Well, they are supposed to be learning from their masters. Admittedly 
in a campaign, they are walking ST batteries usually, but on the 
other hand I often put Aid on my fast strong wizards. The smart 
weaklings love me, but I'm *also* valuable for Trip, blur, and 
similar special effects in combat.



--
						- Mark     210-379-4635
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Large Asteroids headed toward planets
inhabited by beings that don't have
technology adequate to stop them:

				Think of it as Evolution in Fast-Forward.
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