[Salmonfisher11]

Didn't Israeli students show that you can recover audio from the vibrations of bulb filament with a fast photo diode?

I'd test that with a CCD line sensor plus a wide aperture lens and reading it out with 8kHz. Then you have 128 audio pixels that can cover an entire city.

[killjoywashere]

Line of sight might be an issue there. I'm thinking more high-end clandestine eavesdropping. Fun fact: curtains are a pretty good defeat for laser microphones, but if the building is really old and made of solid stone, you can point at the rock instead!

[0cf8612b2e1e]

The rock?! That’s incredible. I would have guessed it was too dense to pick up normal speaking volume. Then again, even the window glass vibration seems pretty magical to me.