What Is a Pulsar?

The universe is filled with dead pulsars, pulsars that have gone quiet. The reason we call it a pulsar is because we only see those beams as they pass by the earth. They're sending bright streams of light continuously out into the universe until they fade. So that's what a pul ar is, an introduction to these weird things in the universe. Next we're going to talk about why we suspected they might exist and how they were actually found. But first let's take a quick break.