[TML] "Dies the Fire"

[Richard Aiken]

On Dec 10, 2007 11:16 PM,  <shadow at shadowgard.com> wrote:
> On 10 Dec 2007 at 20:41, Richard Aiken wrote:
> Given that the flat surface near the rim is gonna be red hot during
> the day, the conditions are more than bad enough. If it wasn't for
> oxidation problems, you'd be able to have lakes of molten lead.
> Probably too hot for lakes of sulfur.

The home of Fire Elementals and maybe also the various Metal Qausi-Elementals.

> Again, without getting too close to the edge (or going over it) it
> gets *really* cold. At night, much less in the permanently shadowed
> places, it's going to be *frozen* air.

Ice Elementals?

What about Jerry's points about renewing/circulating the atmosphere?
Having it spill into the sun without a barrier wall around the core
(call this the Spindle?).  Hmmm.  Is the solar gravity weaker than
"all those millions of kilometers of rock" due to the inverse square
law?  Or will the hole have to get bigger to let it work without a
barrier wall (and thus that loooooong shadow zone).

And what about Jerry's point about the Sun moving toward the disk?
Ah!  Wait one.  The disk is pulling on it equally from all sides, so
the forces cancel out.  Right?

> > > Given that there *isn't* any such thing as orbital velocity (not
> > > until you are dozens of AU out, anyway) and that escape velocity is
> > > in the thousands of km/sec range, you could have some really high TL
> > > societies that never got to a fraction of the disk before dying out.

Jerry was saying all those millions of kilometers of rock are also
millions of kilometers away.  Inverse square law again?  So how bad is
the rim/core gravity anyway?

Hmmm.  Thinking about it, now.  Would the core surface gravity be
higher that the rim surface gravity?  At the core, the disk material
is curving in and around you, rather than back and away.  Or would the
effects cancel out?  Would there be a horizontal component?

> The sun doesn't have to worry about friction, nor about density waves
> going thru it.

Friction?  I don't know.  Isn't there a gas corona around it that
stretches out rather far?  Normally this would have no effect.  But
Suns don't normally bob up and down, either.  Wouldn't moving like it
does mean it would be trailing loose gas along behind, so it would be
constantly moving through a tenuous atmosphere of it's own making?
Not that this would probably have much effect on a human time scale.
But I'd say it's peak apparent height would get steadily lower on a
geological time scale.

I'm not sure what density waves are.  But I know the Sun has solar
storms and hot spots and such.  So it's not a solid body.  So the
constant up-and-down should have internal pressure effects over time.

BTW, since the Sun is only 1/640th of the mass of the disk, I assume
that's why we're saying the Sun is bobbing up and down, rather than
the disk doing it.

> You don't get an airflow due to the different altitudes. That's
> because the presure varies with altitude the same way on both ends of
> the tunnel.

Okay.  But the outside air between the two ends of this real-world
tunnel is free to travel outside the tunnel.  The air can't freely
travel between the ends of a tunnel through the disk.  Doesn't that
make a difference?

> What would get a flow going would be if the pressure at a given
> altitude above the zero-gee plane on side A was different from that
> at the same altitude above side B.

Never mind the above then.  I guess.

> There are other processes that'll tend to make water accumulate
> unless it's really hot down there.

So - given a geological time scale - there won't be any "air holes" by
the time sentience can naturally evolve.  At best, you'd get amazingly
circular, below-sea-level lakes.  Unless there were some active agency
to pump the holes clear.  Or it's hot enough to keep the water
vaporized.

A microgravity ecology in the center of the hole?  One using heat
released from the rocks as a power source instead of light?  Like the
weird life at ocean geothermal vents?

> > Hey!  I just thought of a design reason for having big holes.
> > Incoming debris - comets, asteroids, etc - can't be destroyed without
> > the pieces continuing on to impact the disk anyway.  So if there isn't
> > enough time for robotic tugs to steer such debris away from the disk
> > entirely, big holes exist to allow a chance at passing safely
> > *through* it.

Since you made no comment on this bit, I assume the holes are a good idea?

-- 
Richard Aiken

"Never insult anyone by accident."  Robert A. Heinlein