Nightfall: Can Kalgash Exist: Summary of the Story

Table of Links

Abstract and 1 Introduction

2. Summary of the Story

3. Observables

4. Possible Scenarios and Consequences

The other Suns

Simulation

Conclusion and References

2. SUMMARY OF THE STORY

The short story and the later novel are both set in the same world albeit with minor differences in names and characters. However, the book contains much more detail and we have used names and constraints from the book for the sake of consistency. The story is set on the planet Kalgash which orbits the Sun-like star Onos at a distance of about 1.2 AU (1.2 times the Earth-Sun distance). There are five other stars (Dovim, Tano, Sitha, Trey, Patru) in this system and, as a result, Kalgash has the normal day/night cycle with respect to Onos but with one or more of the other stars always in the sky. The sky is bright enough that no other stars are seen and the inhabitants have no knowledge of the wider Universe. Presumably the motions in this system are complicated enough that the Universal Law of Gravitation was only discovered a few years before the events in the story. The entire extent of the system is 110 light minutes (13.2 AU) and, as far as the inhabitants of the planet were concerned, included all of Creation.

The story (in the novel) begins with an archaeological dig in which the scientists discover that there have been many previous civilizations which regularly destroyed themselves by fire, in accordance with the religious texts of a major cult. At about the same time, a group of astronomers found that the observed motions of the system did not match the predictions of the Law of Gravitation and postulated an additional invisible moon of Kalgash of almost the same mass as the planet. This moon would cause an eclipse of Dovim every 2049 years resulting in a period of absolute darkness, mass madness and the self-destruction of civilization.