Ph103: Discussion Questions 6

Short Answer Questions

1. Describe how the caloric theory of heat provides an explanation of how a heat flows from a hot cup of tea into the colder air of the room.
2. How does the pessimistic meta-induction provide an argument against realism?
3. What is the "divide and conquer" reply to the pessimistic meta-induction? (Chang calls this view "Preservative Realism.")

For Further Discussion

• The pessimistic meta-induction. The history of science is full of false theories, such as the humour theory of medicine, the crystalline sphere theory of cosmology, and the caloric theory of heat.
• Write the pessimistic meta-induction in premise-conclusion form.
• Explain the idea behind each of the premises using a false theory as an example.
• Can you think of any reason why modern theories might not suffer the same fate (i.e. failure and rejection) as these past theories?
• Genuinely successful theories. Psillos says that a theory is only "genuinely successful" if it makes predictions that are "novel" (i.e. not ad hoc), and if it is "mature" (i.e. elaborately developed and precise).
  • Consider a fortune-teller making predictions about your future. The fortune-teller says that this month you're going to encounter a surprise, and you're going to confront something that has long been bothering you. Are these mature, novel predictions? Explain.
  • Suppose mentioned to the fortune-teller that you're very close to one of your siblings. Later in the meeting, the fortune-teller studies your palm carefully and says that the "family line" in your palm is very strong. Is this a genuine prediction? What general characteristics does a prediction that fails to be genuine have?
  • Suppose a restaurant does not wash its glasses with soap or hot water. A scientist predicts that this practice will someday lead to the transmission of a common cold among the restaurant's clients, due to the transmission of invisible microorganisms that can be dispersed or killed by hot soapy water. In what ways does this prediction differ than that of the fortune teller? In what ways is it more or less "novel" or "mature"?
  • Why does Psillos say that only "genuinely successful" theories are relevant for the pessimistic meta-induction?
• 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?