Mountain climbers face many dangers as they brave the cold winds of the peaks they climb. But the most serious thing they face is all in their heads--literally.
Contrary to what fairy tales tell us, there is nothing holding the moon up in the sky. So why doesn't it fall down? Find out on this Moment of Science.
When a train enters a tunnel, it compresses the air in front of it like a piston. Air in a tunnel can't be simply pushed aside--the tunnel walls are in the way.
Doesn't heat rise and aren't mountaintops often damp and cold? Learn more on this Moment of Science.
We’ve been imagining that we’re sitting in a geostationary satellite. That’s a satellite that orbits the equator at the same speed and direction as the earth turns. That means it’s always over the same spot of land, as if it were floating in the sky 22,500 miles up. We let down a rope to pull up some supplies. Will this work? Learn more on this Moment of Science.
Learn about stationary satellites on this Moment of Science.
You can see this more easily by imagining what would happen if the earth were flat. The moon would still travel in a horizontal line above the ground; but because it’s also falling, it would come closer and closer to the flat earth until it collided.
Clouds form when warm, moist air rises to a greater altitude, causing it to expand and cool. Eventually, water vapor in the cooled air condenses into the droplets that form clouds.
Why aren't airliners equipped with parachutes? That question is answered on this Moment of Science.