Walter H. G. Lewin, Ph.D. (born January 29, 1936) is a Dutch astrophysicist and professor emeritus of physics at the Massachusetts Institute of Technology. Born in the Hague Netherlands, professor Lewin achieved his PhD in nuclear physics in 1965 at the Delft University of Technology and came to MIT in 1966.Lewin's major contributions in astrophysics include the discovery of the first slowly rotating neutron star through all-sky balloon surveys, research in X-ray detection in investigations through satellites and observatories worldwide. Lewin is well known for his popular lectures on physics and massive online courses taught on edX and MIT OpenCourseWare.Early life and educationLewin was born Walter Hendrik Gustav Lewin to parents Walter Simon Lewin and Pieternella Johanna van der Tang in 1936 in The Hague, Netherlands. Lewin grew up amidst the turmoil of World War II. His family went into hiding soon after the Nazis seized control of the country. Many of Lewin’s relatives were captured and sent to the gas chambers; his grandfather Gustav Lewin and his grandmother Emma Lewin were gassed in Auschwitz in 1942. To protect the family, Lewin’s father — who, unlike his mother, was Jewish — decided one day to simply leave without telling anyone. His mother was left to raise the children and run a small school she and her husband had started together. After the war ended, his father resurfaced. His parents continued running the school, which strongly influenced Lewin's love of teaching.