1564-1642

Italian Astronomer, Mathematician, and Physicist

Galileo Galilei, best known simply as Galileo, made fundamental discoveries in mechanics and observational astronomy as well as inventing the thermometer and improving the telescope. More significant, his emphasis on direct observation and mathematization of natural phenomena in conjunction with a refusal to allow science to be guided by metaphysical speculation had a transforming impact on scientific methodology.

Galileo was born on February 15, 1564, in Pisa, Italy. He enrolled at the University of Pisa to study medicine (1581), but his interests soon turned to mathematics. His first scientific discovery was made in 1582, when he realized a pendulum's period remains approximately the same regardless of the amplitude of oscillation. Galileo left Pisa in 1585 without finishing his degree. He continued his studies in Florence, where he completed his first scientific treatise, La bilancetta (1586), which describes his improved hydrostatic balance. As Professor of Mathematics at...