Galileo’s Thermometer

Have you ever wondered why a boat made of steel floats in water while a solid bar of steel sinks?
You might also wonder how the measurement of heat is related to buoyancy.

At the start of the 17th Century, scientists wracked their brains to find a way to accurately detect the temperature of a body, air, and liquid. The thermometer was the answer. The principle of buoyancy on which it is based was discovered by Archimedes of Syracuse however, Galileo developed experiments to prove that the density of a liquid changes in proportion to its temperature.

The earliest design of these instruments attributed to Galileo is known as a thermoscope and dates back to 1597.

Many instruments designed by the Accademia del Cimento, Europe’s first society exclusively dedicated to Science, are on display at the Galileo Museum in Florence.

As we know today, temperature measurement is important for medical practice, manufacturing, and scientific research.

Photo: A very delicate glass spiral thermometer designed by the Accademia del Cimento, of which Galileo was a member, is on display at the Galileo Museum in Florence.