I was going to mention spectrometers, but that's with light and can get distorted. Same lines, though, yeah. Eventually, photons or some other sort of particle we can readily detect in the far off future will be able to tell us that sort of thing. Also, radiation detectors and such is probably more likely.
I'm talking out of my ass about most of this - I've only got an interest in it.
Also, I don't want to cut into anything we're discussing, but the live stream from Quakecon is discussing optics and virtual reality in a very detailed manner.
Optics are neat.