Ulbo de Sitter

Lamoraal Ulbo de Sitter (6 March 1902 – 12 May 1980) was a Dutch geologist at Leiden University, where he was the founder of the school of structural geology. De Sitter was known for his research on the geology of the Alps and Pyrenees. His father was the astronomer Willem de Sitter (1872–1934), and one of his sons was the Dutch sociologist Ulbo de Sitter (1930–2010). Provided by Wikipedia