Harold McGee is best-known for his books about food science. In his new book, 'Nose Dive,' he writes about why things smell the way they do — and the ways different chemicals combine to create surprising (and sometimes distasteful) odors. We talk about stinky cheese, cat pee, mask breath and why cooking releases smells. Also, John Powers reviews season 4 of 'The Crown,' in which Princess Diana is introduced.