Categorically Yes … and No

Don’t I know you? (Trees in the Sierra Nevada) Isn’t it satisfying to know the names of things? I just got back from a backpacking trip to the Sierra Nevada with a bunch of geologists. I learned that those pink rocks are full of piemontite, the green mineral around it is called epidote, the gray stuff is andalusite, and those long white crystals are wollastonite. The name is just the first part, of course: The geologists could rattle off the chemical formulas and knew at what temperatures and depths the minerals formed, which tells them the history of the rocks before they were uplifted and eroded so we can poke at them today. But the first part of knowledge, for a lot of things, is identifying, categorizing, naming. The one thing I wished I’d brought with me was my pocket-sized Pacific Coast tree finder (you always forget something). I last backpacked in the high Sierra in my 20s, and the trees were all familiar, but I couldn’t quite recall their names, like I was attending a…