Feb 17, 2014
Q. Can one estimate how far away a flash of lightning is? -- W.T.S.
A. One can tell quite accurately how far away the flash of lightening is by taking a watch and noting the number of seconds which elapse between the flash of lightning and the time when one hears the roll of thunder. If as much as five seconds elapse it is about a mile away since sound travels only about 1100 feet per second, and there are 5280 feet in a mile.