Friedrich Robert Helmert was a German geodesist and statistician. Born in 1843 in Freiberg, Saxony, he worked in a number of academic institutes. The work he did there formed the foundations of modern geodesy. He died in 1917, aged 73

Sir George Howard Darwin was born in 1845 and was the son of Charles Darwin and Emma Darwin. He followed his father’s footsteps into science, but instead focused on geology and astronomy. In 1883 Darwin became Plumian Professor of Astronomy and Experimental Philosophy at the University of Cambridge. He studied tidal forces and formulated the fission theory of Moon formation. He died in 1912, aged 67