How does air pressure work?

Air has weight. You want proof? weigh a balloon, then blow it up and weigh it. Difference? Yes Anyway all things have gravity. The larger the thing, the more gravity it has. The sun for instance has planets revolving around it because of its great size. The Earth though, only has a moon. The weight of the air presses down on everything, even us. When air pressure is greater on the inside of something, it will bulge out. When it is greater on the outside it will push in. A classic example is popping your ears. When you go up a mountain or something the outside air pressure weakens (all the heavy air sinks). This means the air pressure in you is greater than the air outside. This is why you will get a headache. Popping your ears how ever, blows the air out of your ears so that the difference is less. When you go down the mountain the opposite happens.