How to Geek: “Thanks to the internet, it’s incredibly easy to open an app and immediately get a detailed weather report. But what you might not realize is that your phone has some precise weather instruments of its own. Most phones have a barometer inside, and it’s more useful than you might think. What does a barometer do? And why there’s one in your phone Let’s start with the basics. A barometer is a device that measures the gravitational pull on gases in the atmosphere—known as “air pressure” or “atmospheric pressure.” The weight of the air around us is constantly changing, and it can help predict the future…”