The Theme of the Eridian Biology and Steam Power

The Eridians are steam-powered creatures, a fascinating example of alternative biochemistry.

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Rocky's Physiology

The Steam Engine The Hot Blood Rocky explains that Eridians have two circulatory systems: one ambient (210°C) and one hot (305°C). The hot blood is used to power muscles by expanding and contracting. They are essentially steam-powered. The Inorganic Components Rocky's body is mostly inorganic: metallic bones, mercury blood, and silicate nerves. Only a few kilograms of biological material exist. The worker cells build and repair the body. The Implications This biology is a result of Erid's high temperature and pressure. Grace is amazed by the efficiency and resilience of Eridian physiology. The theme of alternative biochemistry is explored.

The Eating Process

The Disgusting Meal The Observation Grace watches Rocky eat. Rocky defecates from his mouth, then eats chunks of food through the same opening. The process is messy and biological. The Explanation Rocky is a monostome: waste and food share the same opening. He uses the hot blood to sterilize the food. The process is efficient but unpleasant to human sensibilities. The Cultural Difference Grace learns that eating is a private act for Eridians. The theme of cultural differences in biology is highlighted.

During Grace's conversations with Rocky

When Grace observes Rocky eating