In a 2006 book that garnered much press for its silly attacks on string theory, author and physicist Lee Smolin provides a list of “The Five Great Problems in Theoretical Physics.” There are many offensive things about this list, starting with the use of the definite article in the title, which implies that people not working on these problems (the majority of theoretical physicists) are working on less-than-great problems. But to me the most offensive thing is that only one of the five problems, I believe, could eventually be resolved by experiment. Most physicists don’t consider a... (p. 32)