My new book, How the Ray Gun Got its Zap! is now out in bookstores, and is available over the internet as well. It's a collection of popular articles on odd optics, and the title essay is a History of the Ray Gun. I've written a new piece on The First Ray Gun, about the appearance of the first Ray Gun used by invading aliens in fiction -- in 1809. The piece, which contains material not in the book, is in the Oxford University Press blog at this address:
http://blog.oup.com/2013/10/first-ray...

Besides the Ray Gun, there are pieces on Edible Lasers (about lasers in which the lasing substance is edible. There's a surprising number of these), Pyrotechnic Lasers (driven by Fireworks, not flashlamps or diodes), The Magic Lantern of Omar Khayyam (in which I investigate how the poet and scientist could have written about a device that hadn't been invented yet), The Telephote (why do we call it a Television instead of a Telephote, the original name for this vision-by-wire device?), Tractor Beams (tracing the device from its first appearance in chapters of a book by Jules Verne -- which Verne didn't write -- to a present-day reality), and This Is Your Cat On Lasers (about how two guys patented the idea of using a laser to play with your cat), and a lot of others. Why are there REALLY seven colors in the rainbow (it has nothing to do with the mysticism of the number seven)? Who invented the Diffraction Grating? How did a spider give us crosshairs in a telescope? Why is the sun always depicted as yellow, if sunlight is the very definition of white? These questions and others are answered in the book.