If you aren't the one doing it, you've at least seen that savvy traveler on an airplane who has a fresh pack of gum in their pocket. They're tossing in a piece as the plane takes off and as the plane lands. It's to help quickly relieve the pressure in their ears by getting their ears to pop. But why do our ears pop and why does chewing gum help? As with so many of these kind of questions, Sci Show makes the science easy to understand.
It's all about air pressure. As the altitude changes, the air pressure around us changes. Meanwhile, the pressure inside our ears, on the other side of the ear drum, doesn't change with the air around us. That creates an imbalance of pressure with the barrier being the ear drum.
There's a small tube called the eustachian tube that leads from the throat to the ear. By yawning or chewing gum the tube is encouraged to open up, allowing fresh air into the middle and inner ear, evening out the pressure. Bringing in new air equalizes the pressure, relieving any pain and, possibly, giving the ear drum a gentle pop.