My father has a wonderful old book published in 1896. It's a textbook for University students on physics. What makes it interesting is that the electron was dis

My father has a wonderful old book published in 1896. It's a textbook for University students on physics. What makes it interesting is that the electron was discovered in 1897. I can't say I've studied the book in detail, but what I did find was something that reminds me a lot of where we are today with dark matter. We understand the problem, and where something ought to fit into it and there's lots of good theories being tried out- but we just don't know what the answer is yet. I suspect we're writing this generation's version of that book right now, and we call the subject "dark matter".