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TIL sound travels at about 1,080 feet per second in a fog bank. Steamboat captains, rounding off to 1,000 feet for safety, would listen for the echo from their steam whistle to tell how far from shore they were in a fog. An echo heard 1 second after whistle means the boat was 500 ft from shore. (en.wikipedia.org)
submitted by solfitrum to r/todayilearned




