Gallileo Thermometer Multicolour 42cm
Galileo Thermometer 42cm
Galileo's thermometer consists of a closed glass tube with colored liquid in which small glass balls are found. The glass balls have equal volumes but different masses, since they contain different amounts of liquid. Below each glass ball hangs a tray that displays a temperature. There are usually eleven glass balls showing 11 temperatures ranging from 17 to 27 degrees C. Galileo's thermometer is a very beautiful concept based on the beginning of Archimedes' Union.
It is available in sizes 42cm and 52cm with 1,045kgr weight.
How the device works
In each glass ball in the liquid, two forces, weight and buoyancy are exercised. When the temperature rises, then the liquid expands, its density decreases and consequently the buoyancy given by the formula: A = p.Vg (where ρ the density of the fluid, g the gravitational acceleration and V the volume of the submerged body) decreases, so the glass balls tend to come down. Conversely, when the temperature drops then the liquid contracts, its density grows, so the glass balls tend to rise. Each glass ball is of such volume and mass as to balance at some position of the tube when the temperature is that indicated by its label. This is because, then, the buoyancy is equal to the weight of the liquid displacing the glass ball.
How we read the temperature
We see in the device that some glass balls are at the bottom of the container and others float on the top. The temperature of the tube is indicated by the glass ball that balances in the water or if you prefer the lower one than the balls that are at the top of the tube.