  In 1626, the Venetian physician Santorio Santorio published the details of
his pulsilogium, a stop clock that could accurately measure one's pulse rate.
He applied Galileo Galilei's insights that the frequency of a pendulum's
oscillation is inversely proportional to the square root of its length.
Santorio's inventions emerged at a time when the natural world and our solar
system were beginning to be mapped in remarkable detail. Santorio was a true
representative of his era, a period in which scientific developments came in
rapid succession and measurements to support hypotheses became the norm.
