Whereas statics, we recall, is that part of mechanics which is concerned with the equilibrium of bodies, dynamics is that part which is concerned with the motion of bodies. The former, as we have had occasion to note, goes back to the Greeks; to Archimedes' discovery of the Law of the Lever and his application of it to the integral calculus. The latter is relatively new; it starts with Galileo.

SECTION 1. GALILEO

Galileo is known by his first name; his family name is Galilei. He was born in 1564 and died in 1642. To believers in the transmigration of souls the date of his death is important. Not only did he die in the year in which Newton was born, conveniently for their speculations, he died shortly before Newton was born. A much more important date is 1636, the year in which he completed the book on which his fame so securely rests, the Dialogue Concerning Two New Sciences. Although many of his brilliant predecessors, beginning with Aristotle, and including that most versatile of versatile geniuses, Leonardo da Vinci, had been interested in the free fall of heavy bodies, Galileo was incomparably the greatest dynamicist of them all. He inherited a dogma and bequeathed a science.

His tomb is to be found in Florence, in the Church of Santa Croce, among those of Leonardo and Michelangelo the artists, Dante the poet, and Machiavelli the politician.