[size=150][b]Richard Feynman (1918 - 1988)[/b], American physicists and Nobel prize holder, published two contributions on the derivation of[b] Kepler's laws[/b] of planetary motions applying [b]Newton's laws[/b] of motion and gravity (this method was used also by Newton himself to prove the correctnes of his assumptions):[br][br]Feynman's Lectures on Physics (three volume book, 1963) - the numerical approach [br][br]The Motion of Planets around the Sun (guest lecture, 1964) - geometric approach[br][br][br][/size]