Hendrik Casimir was a Dutch physicist born on July 15, 1909, in The Hague, Netherlands. He is best known for his work in quantum physics, particularly for his contributions to the field of quantum field theory and the Casimir effect, which describes the attractive force between two close, uncharged plates due to quantum fluctuations. Casimir studied at the University of Amsterdam and later worked at various institutions, including the Institute for Advanced Study in Princeton. His research has had a lasting impact on theoretical physics and has applications in areas such as nanotechnology and condensed matter physics. Casimir passed away on April 4, 2000.