Antiaircraft Sound Locator


An acoustical device used before the invention of radar to detect incoming planes by sound. The stereo horns ran right into the operators ears, like gigantic headphones. To the right is a spotlight for nighttime operation.

Via Wikipedia

Nuclear Explosion

Strange, super-minimalistic raw film of a test nuclear explosion from 1953.  After several minutes of flickering gray and quiet ambient sound, the blast fills the screen all-white, then receeds to a silent, washed-out mushroom cloud.  This is followed nearly a minute later by a sharp, dull blast sound (since the speed of sound is much slower than light).  The video concludes with several minutes of gray clouds.

Via: Nuclear Secrecy blog