Chang's Challenge from Caloric. Chang argues that the caloric theory provided a number of powerful explanations and predictions. First, temperature was defined as the density of caloric. Second, caloric was said to be "self-repulsive," meaning that the particles of caloric wanted to move away from each other. Third, caloric was said to have two chemical states: the "latent" state in which it occupied volume but had no detectable effect on temperature, and the "sensible" state in which it did have an effect on temperature but no effect on volume. By squeezing a volume, it was thought to be possible to disengage caloric from its latent state into a sensible state.
- How does the "self-repulsive" nature of caloric explain how we observe heat to flow in real life?
- How do the "sensible and latent" states of caloric explain why compressing air will cause it to get hotter?
- Laplace reasoned that because of the nature of caloric, a moving sound wave would compress the air around it and thereby make it hotter. Is this prediction "novel" in the sense that Psillos demands? Is the caloric theory "mature" in the sense that Psillos demands?
- Today, we all agree that caloric does not exist, and that the caloric theory is deeply false. The real phenomenon that is responsible for heat is the energy of matter, and typically particles moving about. How is this a problem for realism?
- How do you think the realist should reply to the case of the caloric theory?
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