[TML] "Dies the Fire"

[Timothy Little]

On Mon, Dec 10, 2007 at 02:54:04PM -0800, shadow at shadowgard.com wrote:
> It gets really difficult to avoid gravity levels that'd make Mesklin
> (cf Hal Clement's "Mission of Gravity") look like a low gee world at
> the edges of the disk.

It's not that bad.  Gravity near the edge of an infinitely long
"ribbon" scales only logarithmically with the width of the ribbon, and
a disk will have countering effects from the matter on the other side.
The gravity inside the inner rim's surface would be very strong, but
more on the order of 4 gees rather than 400.


> I don't want to try figuring the pressure at midpoint.

It's easier to work out a back-of-the-envelope figure than you might
think.  The ideal gas law stops being even vaguely useful before you
reach 100 km depth, but after that you can do a decent approximation
by considering the "gas" to become effectively incompressible with a
density probably somewhat higher than water but less than rock.

So the pressure is likely to be on the order of 15 GPa (150,000
atmospheres) near the centre.  Maybe a factor of 1.5 either way.


- Tim