The Growth of Physical Science

actually already amount angles appeared Aristotle astronomy atomic attraction became become body called centre century charge circle complete consisted contained continually course described direction discovered discovery distance earth electric electron elements energy equal experiment explained fall finally followed force four Galileo gave geometry Greek ideas imagined important instance interest kind knowledge known later light lines magnetic mass mathematics matter measure mechanical methods moon motion moving nature needed Newton object observed obtained orbit original particles passed period physics planets position present principle problem produced properties proved published Pythagoreans radiation result round scientific seemed seen showed similar simple space speed sphere square stars substances suggested supposed surface theory things thought true turn universe various waves weight whole