Aron is really into the laser hobby. He currently owns a 5mW green DPSS laser, a huge (in size) 30mW red HeNe, a couple of smaller HeNe's, and several Argon Argon/Krypton Ion lasers. And before he sold it, he used to have a flashtube- pumped ruby laser that had enough power to burn things! Lasers are strange devices that incorporate many diverse fields of science, from electronics to optics to particle physics, high voltage, and chemistry. Some lasers are extremely complex (they just about all are when it comes to operating theory), and some are relatively simple. And some require 480 3-phase power to operate, while some only require a small battery. What very weird, very fascinating things lasers are.