We haven't been able yet to determine in terms of genes what makes a human being a human and not another mammal.

D in Physics under the mentorship of Nobel laureate Abdus Salam in 1957. He was educated at the Sidwell Friends School and attended Harvard University for undergraduate and graduate studies earning a baccalaureate in chemistry and physics in 1953 and a master's degree in physics in 1954. In 1969 he was awarded Harvard's Ledlie Prize.