Math and Arithmetic
Planetary Science

If the earth is 25000 miles around and lightning travels at 670616629.384 miles per second how many times would it circle the earth in one second?

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February 22, 2010 6:20PM

LIGHT travels at about 670,616,629.384 miles per HOUR, not per second!

Converting m.p.h. to miles per second, then the approximate speed of light would be about 186,282 miles per second.

IF lightning travels at the speed of light (which it doesn't!) then 186,282 miles in one second divided by the approximate circumference of the earth, i.e. 25,000 miles, equals 7.45, or say seven and a half times round the earth, or once every 1/7.45 = 0.13 seconds.

However! Lightning does not travel as fast as light! It has been approximated that lightning, on average, travels at about half the speed of light. So, one continuous flash of lightning, in a tight circle close to the earth, could travel round the earth 3.725 times, approximately.


Note: I agree the " tethering " of the cloud and the earth via the electrons and protons from each, does not travel at the speed of light.

However; this connection between the two creates an "electrical bolt" which in turn creates a flash of light, which, as the name suggests, does travel at 300,000 kms/sec i.e. the speed of light.


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