Sometimes the universe freaks me out a bit. Monday I guest taught “Ms. Stollwerk’s” world history class in the South Bronx. I volunteered to teach the scientific revolution since I took an excellent class (from the inimitable Prof. Manning) on that period of history at MIT. In the course of one of my lectures to these high schoolers, we talked about gravity and why objects fall toward the Earth (i.e., why doesn’t gravity pull us upwards?). And I explained that everything has a gravitational pull, but that small objects, such as this marker or that sticky-note pad, have tiny, tiny gravitational effects that are way too small too feel. Only massive objects, such as the Earth, tug at us with enough force that they affect our lives. And, lamely attempting to connect to the students, I followed up this statement with “I’m sure there’s a Yo Mama joke in there somewhere…”

Yes, okay, I’m at least a year too late with the joke. And yes, okay, no one laughed. But, I get home from NYC and check my RSS feeds and what is the XKCD comic for the day?

Freaky.