Sunlight and nightime for tori

From: Al Globus
To:
Sent: Thursday, March 22, 2001 4:33 PM
Subject: Re: [spacesettlers] O'Neil cylinders

[snikt]
> don't keep the torus pointing towards the sun. Use artificial light and
power
> satellites to beam energy to the colony.

You don't need either to point the torus to the Sun or to use artificial
light. Simply make the torus spinning with its axis perpendicular to its
orbital plane, put a mirror inclined 45 degrees, always pointing to the Sun,
"over" one of the sides, and put a conic mirror at the centre of the torus.
The Sun hits the 45 degrees mirror, the reflected sunlight hits the conic
mirror, and then the inner surface of the torus. (I'm assuming a torus with
a transparent "roof", probably using water extracted from a NEA for
shielding. That would allow sunlight to come in.)

O'Neil didn't like conic mirrors - it seems that he thought that the
distorted elliptical reflex of the Sun would be disturbing - but frankly I
think that that concern makes no sense; people rarely look directly at the
sun (for obvious reasons) and I think that everyone would be content by just
having sunlight, no matter if the sun looks like a disk or a ring or
whatever.

More thoughts: there could be an opaque "half-roof", covering half of the
internal circuit of the torus at any given time, rolling over the
transparent roof, making a cycle every 24 hours. That way, there would be a
24-hour cycle of "day" and "night", with the odd property of half the city
being in daylight and half in darkness at any given time. O'Neil proposed
something like that for allowing a truly 24-hour city, where there would be
people working at all places at any time with no need of nightshifts.

I really liked Robert Reed's classification for space enthusiasts, and as
you can see from the text above I'm a cross between a O'Neiler and a
Lewisan: I'm addicted to space settlements, *but* please make them using
materials extracted from NEAs.

(Sometimes I'm also a bit "Savager". Maybe it is possible for Humanity to
also thrive in zero-g habitats. Unlike Savage, however, I don't believe that
the inhabitants of those weightless micro-worlds could have Earthling
physiques in any conceivable way. Moreover, I don't see the point in making
them having Earthling physiques. If I were Savage, I would strip way the
section "Sing the Body Electric" in the chapter about Asgard and substitute
it for another section named "Human beings born and raised in space will be
freaks. And so, what?"...)

[snikt]
Lucio Coelho