I'm working for the physics department over the next two weeks, in the optics lab. I was an optics tech over the summer, which was a ton of fun, so this was sort of a reminisce. Except not. I mean, look at this.
This is a monochromator. This is what people used to make monochromatic light before we had lasers. BEFORE LASERS SERIOUSLY WHY DO WE HAVE THIS!?
Reason my job is occasionally tolerable: I built these!
With the addition of a laser, these become interferometers. The near one is a Michelson interferometer, the far one is a Mach-Zehnder interferometer. They're pretty much awesome.
Reason I feel accomplished: the optics went from this (only worse):
in the course of four hours. It still makes me deeply sad that I had to label a good half of the large boxes "historical optics", because that means we don't have nearly enough modern optics.