Answer to Question 1
Steel is used extensively in reactors to withstand the high pressures internal to the
reactor. Embrittled steel cracks more easily. High pressures and cracks are a combination
that can give an engineer nightmares.
Answer to Question 2
It is to be hoped that students' normal nave optimism has been tempered by the
reality of the limits as discussed in this chapter. Growth is fine as long as it does not lead to
greater problems. Most ecological niches are already occupied, and even when a new niche
looks half empty, it will be completely full in a single doubling time.