Nightfall is definitely an interesting read and I love the spirit of the paper. But I think one of the major features of the Kalagash system is its periodicity.

Nightfall is definitely an interesting read and I love the spirit of the paper. But I think one of the major features of the Kalagash system is its periodicity. The total eclipses may only happen in very long cycles to cause the cataclysmic panic in the story and the resulting collapse of the societies. And I think it's one of the most difficult prequisite to fulfill. Unfortunately, the authors had not attemped to consider whether such long periodicity could be possible.