Exactly thirty-three years ago this month, the Naval Undersea Warfare
detachment in Hawaii performed a demonstration that had previously been very impractical. A common styrofoam coffee cup was lowered to a depth of 15,000 feet into the ocean off Hawaii. The recorded sea pressure at this depth was 6,674 PSI
(exceeding 3 tons per square inch).
Results of the demonstration were recorded for posterity in a wood-framed and brass shadow box (photo). That is a good thing because these days the tiny cup has the consistency of a coarse powder held together only by gravity and some weaker nuclear force.
We may safely assume that the coffee cup used had been 8-oz., since the advent of supersizing would not come until a decade or two later. Shown with the test cup is a modern 8-oz. coffee cup.
Virtually all of the air pockets in the porous, styrofoam cup were eliminated by sea pressure acting uniformly in all directions at once. For this reason, the cups shape was not destroyed, but it was compressed to about 1/3 its original height and 1/10 of its original volume.
Has anyone else seen this display? Perhaps one of you were present during the demonstration.
This little story is not finished yet. Submarines are always silent and strange.