* Astronomy

Sir Norman Robert Pogson KBE (March 23, 1829 in Nottingham - June 23, 1891 in Chennai, India) was an English astronomer.
His most notable contribution was to note that in the stellar magnitude system introduced by the Greek astronomer Hipparchus, stars of the first magnitude were a hundred times as bright as stars of the sixth magnitude. Pogson's suggestion in 1856 was to make this a standard; thus, a first magnitude star is 1001/5 or about 2.512 times as bright as a second magnitude star. This fifth root of 100 is known as Pogson's Ratio.
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