Astronomy Word of the Day

This week and last week I've been teaching my class about stellar evolution -- about the births, lives, and deaths of stars. I'm happy because it's my favorite topic.

Today's lecture was entitled "The Bizarre Stellar Graveyard." We talked about the weird remnants that are leftover after a star dies. I taught them about white dwarfs, neutron stars, and black holes.

Of course, black holes is a fun topic to teach. Everyone is relatively interested in what you have to say. (One student asked me last time excitedly, "When are we going to talk about black holes?!" I told him, "Next time..." Sadly, he wasn't in class today.)

And I got to teach about something everyone is excited to hear about: spaghettification. My favorite part of the lecture was these two slides, as I told them what would happen if you were to fall into a black hole:


Here's what's going on in this scenario.

Remember, the force of gravity depends on distance: if two objects are closer together, there will be a stronger force between them than if they were further apart.

Tidal forces happen when the gravitational force is stronger on one side of an object than the other. Tidal forces between the Earth and the Moon cause the tides in the ocean.

Spaghettification is tidal forces to the extreme. Because the force at your feet (closer to the black hole) is stronger than the force at your head (further from the black hole), you are stretched long and skinny (like spaghetti). You are spaghettified. As you fall into the black hole, these tidal forces are so strong that you will not survive, but rather ripped to shreds. (Yikes!)

In other words, the black hole wins.

The term isn't used in the textbook, but I knew it was definitely worth mentioning. I challenged them to use it in casual conversation this week. And I challenge any of you to do the same. :)