Air Conditioning: Still Cool After 110 Years Image Credit: SuperStock, Inc./Getty Images If you've ever sat inside on a sweltering summer day, basking in the miracle of man-made coolness, you have Willis Carrier to thank. Today, his invention, the mechanical air conditioner, turns 110. It was on this date in 1902 that Carrier, who was a young research engineer fresh out of Cornell University, finished his plans to control the humidity in a printing company. The Brooklyn printer needed a system that would stabilize the humidity so the dimension of the paper would remain consistent and align correctly with the presses. A machine that was originally designed to help paper keep its shape, quickly found uses in just about every aspect of everyday life. From movie theaters to malls, factories to fitness centers, Carriers invention made many other innovations possible. "Willis Carrier had a new idea and dared to dream big," said John Mandyck, chief sustainability officer at UTC Climate, Controls & Security, in a video on the company's website. By doing so he literally changed the world. Image Credit: Carrier Corporation/AP Photo Image Credit: Ã"Â© Bettmann/CORBIS