Brain regions that activate when we hear speech out loud are also active when we think about speech.
Burning is the release of energy, and some materials like metals, can absorb energy better than others, such as wood.
Polar bears evolved during a time when the North and South poles were not connected by ice or land, so they stayed at the North Pole.
Small bodies like asteroids and comets are shaped more by their geological makeup than by gravity, which molds planets and moons into spheres.
About 4.5 billion years ago, the solar system was just a giant, spinning cloud of gas and dust. Today, it's flat. Here's how that happened.
Some animals, such as poison dart frogs, carry enough toxic chemicals to kill multiple adult humans, but they've evolved tricks to avoid poisoning themselves.
These planets are mostly made of gas, but a spaceship would have a rough time trying to get through a giant planet like Jupiter or Saturn.
Particle accelerators can help scientists measure the smallest and largest particles in the universe.
Our planet is constantly moving, racing around the sun and spinning on its axis. But how fast does it move?