Nightfall: Expanded Version By Isaac Asimov & Robert Silve..

This story concerns the planet Kalgash, which is lit by six suns: The
primary Onos (yellow), Trey (white), Patru (white), Trano (white, I
think), Sitha (also white, I think), and Dovim (small and red). Since
all of Kalgash is always in sunlight, the people of Kalgash are
unfamiliar with darkness and are therefore extremely frightened of it.
Even 15 minutes of darkness (as demonstrated by a Tunnel of Darkness at
the Jonglor Centennial Exposition) is enough rattle any Kalgashian, and
cause many to go insane.

Unbeknownst to most Kalgashians, Kalgash has a satellite (dubbed
"Kalgash Two" by the astronomers who discover it by noting its
gravitational effects on Kalgash's orbit). The light from Kalgash Two
is drowned out by the light from the six suns, so no one sees it.
However, every 2,049 years, Kalgash Two eclipse Dovim, on a day when
Dovim is the only sun in its hemisphere (the other five are on the other
side of Kalgash). At that time, Kalgash Two is at perigee, and Dovim is
at its greatest distance from Kalgash, so Kalgash Two has seven times
Dovim's apparent diameter. As a result, Kalgash Two eclipses Dovim for
over half a day, exposing all of Kalgash to Darkness and causing tens of
thousands of Stars to become visible. The combination of the Darkness
and the Stars drives everyone mad! The Kalgashians, in a desperate need
for light, burn down all their cities, plunging their societies into
barbarism. This cycle has happened at least 7 times, according to
archeological records. Its about to happen again. A fundamentalist
religious group known at "The Apostles of Flame" has been trying to warn
people of the coming disaster, but they come off as religious fanatics,
so few people listen. When a group of scientists discovers the coming
disaster and tries to warn the world, they too are considered crazy,
tarred by association with the Apostles' preachings of doom unless the
people repent their sins. Thus, the people in general don't make
preparations, and go nuts when the eclipse hits.

Nits: When Kalgash Two eclipses Dovim, the other five suns are on the
other side of Kalgash from Kalgash Two. Shouldn't light from those suns
light up Kalgash Two, and enough of it reflect off to relieve the
Darkness?

Why don't the Apostles (and their industrialist supporters) and the
scientists simply tell everyone to stay indoors with plenty of battery
powered lights, and lobby governments to install outdoor lights in all
the cities? The lights would keep everyone sane.

The book uses equivalent English terms for Kalgashian units of distance
and time. Thus, the Kalgashian mile is roughly equivalent to the Earth
mile, and the Kalgashian hour is roughly equivalent to the Earth hour.

Page 151 of hardback version: An astronomer named Beenay 25 gives the
speed of light as 185,000 Kalgashian miles per Kalgashian HOUR, as
opposed to the Earth figure of 186,282 Earth miles per Earth SECOND.
The Kalgashian figure would seem to be impossible unless Kalgash is in a
universe where the speed of light is 3,600 times slower than in our
universe.

I wonder why Kalgashian names have numbers at the ends.

On Wed, 21 Nov 2007 22:47:06 -0800 in rec.arts.sf.written, Tim Bruening
<tsbrueni.RemoveThis@pop.dcn.davis.ca.us> wrote,
>Nits: When Kalgash Two eclipses Dovim, the other five suns are on the
>other side of Kalgash from Kalgash Two. Shouldn't light from those suns
>light up Kalgash Two, and enough of it reflect off to relieve the
>Darkness?

Maybe, but it sounds like those folks have really poor night vision.