![Willem de Sitter Image source: Universiteit Leiden Willem de Sitter Image source: Universiteit Leiden](http://www.timeone.ca/wp-content/uploads/2012/06/Willem-de-Sitter.jpg)
Image source:
Universiteit Leiden
Willem de Sitter was a Dutch physicist, astronomer and mathematician who solved his friend Einstein’s general-relativity equations for an empty universe.
Image source:
Universiteit Leiden
Willem de Sitter was a Dutch physicist, astronomer and mathematician who solved his friend Einstein’s general-relativity equations for an empty universe.