Physics & Math

What Is This? Whipped Petroleum?

Hint: It makes your hard drive work and also makes pretty colors in the sky. 

Image: R. Mark Bessette

This image depicts the magnetic field lines between two bar magnets. Earth has a field of its own that protects us from charged particles from the sun. It channels some of these particles toward the poles, where they can collide with air molecules and release energy in the form of light, producing brightly colored aurora .