Bent Light and a bit about Nick...

From: Dane 'Danger' Johnson (dane@frame.com)
Date: Tue 20 Feb 1996 - 21:53:00 EET


Nick, in an impassioned plee for tolerance, characterizes himself as:

>that racist, chauvinist, bigoted xenophobe (and effete,
>decadent shirt-lifter; not to mention demon-worshipping Satanist) Nick Brooke.

You forgot Unwashed and Hairy... :) I must, however, plead ignorance about
the term 'shirt-lifter'. Not that this is particularly relevant to Glorantha.

==============================

Ian, in a post about what Moons look like, presented the following
interesting fact and question:

> Add to this the known
>fact (Greg imparted wisdom) that light on Glorantha does not travel in
straight
>lines, but rather curves upward because of its afinity to the sky, and you
soon
>come to the conclusion that only the lower face of the moon can be seen from
>anywhere on the surface world.
[Snip]
>I think there must be other interesting effects due to the bending of light.

The thing which occurs to me about this, right off the bat, is that if Light
is really going to curve up towards the sky, then Glorantha will have a
horizon even though it's flat. All we have to do is tip Ian's triangle with

the moon on it's side.

Consider a man standing in the middle of the Wastes of Prax. He looks out
over the desert. Light from some distance away streams towards him, but in
a curved path, attracted by it's affinity to the Sky Dome.

Light coming off of the nearby shrubs will be moving mostly straight, both
because the "source" of the light is close (and so the light hasn't risen
much towards the sky yet) and because the amount of curvature in the light's
path can't be too weird, at least under normal circumstances (assuming, of
course, that Glorantha light is at least similar to Earth light in most
respects and that vision works more or less the same way).

Light coming off of a Morocanth standing, say, a mile away will be rather
more curved. The light which the man uses to actually see the Morocanth
travels in a curved path from the Morocanth to the man's eyes. Light
leaving the Morocanth in the direction of the man would curve up and away
into the sky, missing the man's eyes. Instead, the light the man uses to
actually see the Morocanth would be that light which travelled somewhat more
parallel to the ground, to begin with.

Really, it's like trying to make a basket in basketball. Instead of curving
the ball overhand, however, because gravity pulls it down, you have to pitch
it underhand, because the Sky Dome is pulling it up.

Anyway, my point is that, eventually, something will be far enough away from
the man that all the light coming from it has been pulled up into the sky,
and none of it hits the man's eyes and he can't see it. The closest point
at which this happens would be the Horizon. Standing up higher allows you
to see beyond this horizon, because by raising yourself up you'll be able to
catch some of the light which was passing over your head...

Of course, this might make for some strange optical distortions of distant
objects (it would tend to make it look like you're standing at the bottom of
a bowl -- by looking straight ahead, you'd be picking up light from the
'ground' at the horizon. Also, the first thing visible about something
crossing the horizon would be the part of it close to the ground, since
light coming from above that point would be missing your head...), AND it
assumes generally Earth-type vision and physics. Still, it is interesting....

Dane

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