The pilots were told that if they dropped the sphere into the ocean, their current position could be worked out by allies in the region and they would be rescued. But the sphere was too heavy to float and contained no electronics, or anything for that matter, inside. So how did it work?
Turns out the spheres were made with a specific thickness so they would be crushed by the ocean’s pressure at about 1km deep. At this depth, one finds the SOFAR channel which acts as a waveguide for sound, meaning low frequency sounds can travel in excess of 3,000 miles in this layer of water.
When the sphere, or sofar bomb, imploded, the sound would travel across the ocean where allied underwater listening posts and submarines could pick it up. Based on when the noise was heard, it was possible to triangulate the origin.
Bonus Fact: Humpback whales use the SOFAR channel to communicate over large distances!
via science
Reblogged from science tumbled.
