Larry Niven & Jerry Pournelle' "The Mote in God's Eye" (novel, space opera): Star-faring humans blockade "Moties" to their home star system
Story summary.A clearly alien probe is detected in a far-off human ruled star system. Trapping it yields a dead alien who obviously traveled 35 light years in a solar sail powered slower-than-light craft from a certain star system. So two human warships, one with a lot of civilian crew, go to investigate the system. System is "Mote" & natives are "Moties" to humans.
At the heart of the story is the complex FTL technology the humans use, the peculiar biology of Moties, & the peculiar nature of space near Moties' home world:
- FTL travel is possible only between "Alderson Points", small regions of space near star systems. Some stars have no such point, others have more than one. Travel between points is instantaneous; elsewhere it slower than light. Each point leads to a specific pre-determined point in another system.
- Moties are specialized at birth: "Masters" give orders, "Engineers" are good at tinkering with gadgets, "Mediators" specialize in communications, ... And while two individuals of different sexes must mate to produce an offspring, each individual spends part of its life as female & part as male, periodically switching between the two. And while female, it must quickly become pregnant, or the internal hormonal imbalances will kill it. This means practically uncontrollable birth rate. Which leads to a cyclical civilization: rise, fall to primitive level, rise, ... Moties are close to the point where fall must soon occur when humans arrive.
- Alderson point after the first jump from Moties home system lies in the corona of a star. Human ships can survive here because of a certain shield; unshielded, you get instantly cooked.
- Some reviewers classify it as a first contact story. To me, it read more as space opera than first contact.
- Moties of different castes - functions - have differently colored fur. I wonder if some of the colors reflect one of the author's personal prejudices: Whites on top, then White+Browns, then Browns.