Science in the most common words

My friend Dave linked me to this text editor which restricts you to the 1000 most commonly used words in the English language, as inspired by Randall Munroe's Up Goer Five. I wrote up a summary of my research:

There are some tiny but heavy stars that are left over after normal stars die. Imagine our whole sun---hundreds of hundreds of our worlds---forced down to fit inside a city. We don't know exactly what's inside the tiny stars because the stuff there is pretty weird, but we have some ideas. 

Sometimes two of these tiny stars go around each other, like our world goes around the sun. When they go around really fast and close together they make waves in space and time that we try to see from our world. As the waves go out the stars move closer and closer together until they hit each other. 

The stuff inside the stars gets moved around when they're close together, so different kinds of stuff make different waves. Also, when they hit each other, sometimes they make a new star and sometimes they fall in to nothing (falling into nothing is another cool story). If we see these waves, the way they look at the end will tell us something about the weird stuff inside these tiny stars.