5/21/1471 Albrecht Durer, artist, wrote The Four Books on Measurement, he 5/21died in 1528 at age 56
5/21/1792 Gaspard Coriolis, physicist, Coriolis effect, he was the first to coin the term work, he died in 1843 at age 51
5/21/1873 Hans Berger, psychiatrist, first to study brain waves with electrodes, he labeled the waves alpha and beta waves, he died in 1941 at age 68
5/21/1850 Giuseppe Mercalli, described the effect an earthquake had on an area, remembered for the Modified Mercalli Earthquake Scale. He died in 1914 at the age of 64.
5/21/1860 Willem Einthoven, devised the electrocardiogram, he died in 1927 at the age of 67.