AUSTIN (KXAN) — For more than 400 years, meteorologists and weather nerds around the world have relied on a simple tool to predict the weather: a barometer. You’ve probably heard of a barometer before. It’s a surprisingly simple device that can give people a heads up when it will rain next.
First dreamed up by Italian mathematician Gasparo Berti, the device was officially invented by Evangelista Torricelli in 1643. Initial experiments involved filling a glass tube with water and standing it straight up in a tub of water. Shockingly, the water did not drain from the tube.
Scientists at the time weren’t sure why this was the case. They believed a vacuum had been formed in the tube, and this is what kept the water from pouring out. This, however, wasn’t the case. Torricelli discovered air pressure was to blame.
This tube filled with a liquid, later mercury, is what would become a barometer.
What you’ll learn in this First Warning Weather University lesson:
- What is air pressure?
- How does it keep the liquid from pouring out?
- How does this liquid help us predict the weather?
You can watch the video above to learn more. If you want to learn more about how meteorologists predict the weather, check out these awesome lessons:
- What do weather balloons do?
- How do storm chasers help meteorologists in severe weather?
- What are high and low pressure systems?