Galileo's+Thermometer

=Galileo's Thermometer!= =Matthew D.= =It is named after the famous, Italian physicist, Galileo Galilei. In part, it is a thermometer, but it is much, much, much, more than it meets the eye.= = = Obviously, a thermometer is a sealed glass cylindrical object, that contains a liquid which is usually mercury, which is a liquid that can be found in your thermostat. The liquid mercury expands and contracts when heat is applied. Regular thermometers measure the temperature in your surroundings. But Galileo's thermometer DOES the same exact thing, but in a very unusual manner.

First things first, Galileo's thermometer is a large glass cylindrical object filled with water. It may sound similar to a regular thermometer, but inside the liquid, are little glass balls each filled with water (or it can also be alcohol but is usually water) and has a little bit of air in them, also they have weights attached to them! The air inside the glass balls created buoyancy, making it able to float inside the thermometer properly. Its pretty cool how you can measure the temperature with just water, heat and air!

It looks like this: The liquid glass balls have different densities! The glass balls are different shapes so by adding the weights to the glass balls, it gives the glass balls different mass to volume ratios. The weights attached to the glass balls have numbers on them to tell the temperature. The maximum temperature it can measure is determined by the size of the thermometer (the bigger it is, the higher up it can measure). But as of now, you may wonder what does that have to do with telling the temperature? Its has to do PLENTY with temperature.

There is a very basic and simple concept that, if the temperature of the air outside changes, so will the temperature of the water will change around the glass balls in the thermometer. Meaning that the water inside the thermometer will either expand or contract. So that means, when the temperature changes in the liquid, the densities of the glass balls will change, because of the expansion or contraction. Meaning at any given density, the glass balls will move up and or down depending on the temperature, pretty ingenious eh? And the glass ball that sinks to the bottom or furthest down is the approximate temperature in your current surroundings! How cool is that??!?!?! Galileo's thermometer no longer serves a real purpose, because it approximates the temperature and you cant accurately tell the temperature accurately. But it can be used as a decorative purpose, and wouldn't it be cool to have one of these in your house?

Sources are as follow: http://en.wikipedia.org/wiki/Galileo_thermometer http://www.howstuffworks.com/question663.htm http://physics-history.suite101.com/article.cfm/galileos_thermometer []