Whats the red liquid inside a thermometer?
As kids, we suspected it was Dracula’s blood. As adults, we learned the truth. Sadly, it’s a lot less interesting. In most cases, the red stuff you see in a thermometer is either alcohol or mercury. The California Energy Commission offers an easy-to-read explanation of how thermometers work. Simply put, alcohol and mercury expand when heated. In a standard bulb thermometer, this means the liquid will rise as the temperature increases. Howstuffworks features a section on how to make your own thermometer out of household stuff (jar, straw, chewing gum, etc.). Of course, a store-bought thermometer will run you only about $5, so this may not be the best use of your time, but our craft-oriented readers may find it interesting. Many people believe good ol’ Gal
