Willem Hermsen (born September 7, 1947 in Hilversum

Hilversum

is a municipality and a town in the Netherlands, in the province of North Holland. Located in the region called "'t Gooi", it is the largest town in that area. It is surrounded by heathland, woods, meadows, lakes, and smaller villages...

, Noord-Holland) is a former water polo

Water polo

Water polo is a team water sport. The playing team consists of six field players and one goalkeeper. The winner of the game is the team that scores more goals. Game play involves swimming, treading water , players passing the ball while being defended by opponents, and scoring by throwing into a...

 player from The Netherlands, who finished in seventh position with the Dutch Men's Water Polo Team at the 1972 Summer Olympics

1972 Summer Olympics

The 1972 Summer Olympics, officially known as the Games of the XX Olympiad, were an international multi-sport event held in Munich, West Germany, from August 26 to September 11, 1972....

 in Munich

Munich

Munich The city's motto is "" . Before 2006, it was "Weltstadt mit Herz" . Its native name, , is derived from the Old High German Munichen, meaning "by the monks' place". The city's name derives from the monks of the Benedictine order who founded the city; hence the monk depicted on the city's coat...

. Two of his brothers, André

André Hermsen

Andréas Hermsen is a former water polo player from The Netherlands, who finished in seventh position with the Dutch Men's Team at the 1968 Summer Olympics in Mexico City, Mexico. His brothers Henk and Wim also played for the Dutch National Team and competed at the Summer Olympics.-References:*...

 and Henk

Henk Hermsen

Hendrik Willem Hermsen is a former water polo player from The Netherlands, who competed in two Summer Olympics for his native country. In 1960 he finished in eighth position with the Dutch Men's Team. Four years later in Tokyo he once again came in eighth with the Holland squad...

, also played water polo on the highest level, and represented The Netherlands in the Summer Olympics, in 1960 and 1964.

Since 2003, Hermsen is a professor at the University of Amsterdam in Astrophysics

Astrophysics

Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties of celestial objects, as well as their interactions and behavior...