David Harper has a BSc in mathematics and astronomy from University College London and a PhD in applied mathematics from the University of Liverpool. In his early career, he was a professional astronomer. He taught astronomy and mathematics at Queen Mary University of London and worked at the Royal Greenwich Observatory in Cambridge. His areas of astronomical expertise are celestial mechanics (calculating the orbits of planets and satellites) and positional astronomy (calculating the positions of the Sun, Moon and planets). He currently serves on two Commissions of the International Astronomical Union (the world governing body of astronomy) devoted to these fields.
These days, David is paid to do computational biology, though he continues to enjoy astronomy in his spare time.
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