[TML] "Dies the Fire"

[shadow at shadowgard.com]

On 10 Dec 2007 at 14:02, Stuart Frew wrote:

> > So . . . a fantasy world that really IS a "flat earth."  The Sun would
> > always be about at dawn, right?  So would you call it Dawnworld?
> > There'd be a permenantly Light and Dark side to everything, wouldn't
> > there?  Wait one.  Shadow squares, like with Ringworld?
> >
> I believe that the sun could (technically, if you ignore the physical
> effects of motion on the sun) bob up and down through a hole in the
> middle.

Since the motion is "free fall" under the influence of the disk's 
gravity, there shouldn't *be* any effects on the sun from the motion.

> So the sun would always be on one side but it could rise and set.

No, half the time it's on one side, half on the other. 

A similat sort of situation can be set up that's a *bit* more 
intuitive.

Bore a hole thru the earth from the north pole to the south pole 
(lined with unobtanium, of course). Pump it out to a perfect vacuum 
and drop a bowling ball.

The ball will start falling, gaining speed as it goes (but not at the 
usual rates as the gavity it experiences decreases linearly from 1g 
at the star to zero g at the center of the earth and then increases 
the same way after it passes the center).

It hits max speed at the center and slows down until it comes to a 
rest the same distance from the center it started at (but on the 
other side of the globe). Then, being unsupported, it starts falling 
again.

It'll repeat forever as long as it is ventered in the hole and 
there's no air resistance.

The sun can do the same thing in the hole of the Aldreson disk, 
except since the disk is so thin, we can treat it as being subject to 
1g towards the center at all times.
 
> How do the weather patterns form, is the disk spinning at all?

I figured on it spinning once a year. Which means that at 1 AU out 
from the center, it's moving around 30 km/sec. At the outer edge (5 
AU out) it's doing 5 times that. And at the inner edge (.5 AU?) it'd 
only be doing 3 km/sec.

I think this would cause tighter, smaller cyclonic storms but I'm not 
positive. But if what matters is the *difference* in velocity as the 
air masses move sunward/antisunward, then the differences may well be 
a lot lower than on earth givoing larger, looser cyclones.

I also need to work out how atmospheric absorption affects the light 
at different times of day and how that affects atmospheric temp at 
various "latitudes" (distances from the center)

--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com