A handsome, intelligent, and very well respected reader of my posts here on The Prompt asked me the most flattering question:
Your posts make science so fun and understandable! Why couldn’t my high school science classes have been more like this?
OK, the most honest answer would be I don’t have a fucking clue. I write articles about black holes and hippos that use crappy GIFs and occasional profanity for cheap laughs. I have a bachelor’s degree in physics and a masters in meteorology. In my day job I write patents. Literally nothing about me suggests I’d be qualified to tackle issues of pedagogy.
On the other hand, why not give it a shot?
I’m just spitballing, but here are some possible explanations for why you enjoy my science writing more than your high school science classes, presented in classic top-10 form:
10. Your teacher required you to use icky equations. Reading my articles you are free to gorge on squishy words. So basically, your teacher was your mom trying to provide you with a balanced diet at home and I’m your grandma spoiling you with Reese’s Puffs for breakfast, lunch and dinner when you come to visit.
9. Everything in high school is boring. (Exceptions include other people, alcohol, drugs, music, sports, and I guess basically everything that happens outside of the classroom.)
8. I haven’t made the topic more interesting—you’ve just taken a new interest in boring things. Congratulations!
7. Your teacher made you learn the lame parts of physics, biology, etc. first. Like starting with scales on a piano. And summer happened just as they were about to teach you to play Chopin. So, while your teacher started with an elaborate description of what makes a successful ecosystem, I skipped right over to “Did you know hippos could have lived in Louisiana?”
6. You didn’t have a bad science teacher. You just had a bad teacher. Give me a shitty enough English teacher and I’ll make Chaucer seem as exciting as Angels and Demons.
5. Understanding complex topics and successfully explaining complex topics are totally different skill sets. It’s difficult to do two things well. When’s the last time you met a successful doctor-farmer? Only those of us who have devoted years of our lives to avoiding any other interesting pursuits (like rewarding careers) are qualified.
4. It not your teacher’s fault. It’s yours. I hated my AP Chem teacher and basically refused to pay attention (or learn any chemistry for a decade after). But other friends who took his organic chemistry class worked really hard and ended up loving him. Despite the fact that he had an unseemly amount of hair growing out of his ears.
3. In your teacher’s defense, Newtonian gravity is terribly boring. At least until you learn that Newtonian gravity can be used to predict black holes. Then it’s fascinating. If your physics teachers failed to mention this fact then yeah, maybe they were just bad.
2. Did you ever think that maybe your science teacher was too busy building a meth empire out of their garage to give a damn about teaching you?
1. Your high school science teacher did not have GIPHY.
 Am I about to use a footnote on a top ten list to explain how Newton’s law of gravity predicts black holes? Damn right I am. So buckle in.
To understand how to get from Newtonian gravity to black holes, you need to first understand the concept of escape velocity. Large massive bodies, like planets and stars, have very strong gravitational fields. In the case of the Earth, its gravitational field keeps both people and moons “stuck” in orbit around it. (Well, we would “orbit” around the earth if we weren’t constantly slamming into its surface, but in either case we are still stuck). To “escape” from the Earth, a person needs to get in a rocket ship and move really fast—at least as fast as the escape velocity, which on Earth is about 12 km/s. If you blasted off in a rocket ship that was traveling slower than the escape velocity, the gravitational force would win and pull you back to Earth.
This all follows from an understanding of Newton’s law of gravity. If you do the math, you find the following equation for the escape velocity (ve) from a body of mass M:
Here, r is the distance you are from the center of the massive body (i.e., a planet or a star).
The key point here is this: as M gets larger (i.e., you increase the mass of said planet or star) and/or as you get closer to the center of the massive body (r decreases), the escape velocity increases.
So far so good. But this seems like stuff more relevant for Elon Musk and SpaceX—what the hell does any of this have to do with black holes?
Well, we know light has a constant speed—it’s about 299,792,458 m/s. It’s very, very fast, but it’s still finite.
In 1783, the clergyman/jack-of-all-sciences John Michell realized if M was large enough and r was small enough—that is if you had a really, really massive body confined to a really, really small volume—the escape velocity could exceed the speed of light. It’s like when you try to fit a
Only bad things can happen…
So imagine you have a really big star out in space shining brightly that suddenly shrinks down to some magically small size, such that the escape velocity exceeds the speed of light. Well now whatever light that star continues to produce can never escape the star’s gravitational pull. The star goes dark. And you end up with a black hole. This is actually what happens when really big stars die (i.e., run out of fuel): they collapse under their own weight until they are small enough to become black holes.
Now, Newtonian gravity is only approximate—you really need Einstein’s theory to properly understand black holes. Still, like Michell did, you can get the gist. Really massive bodies that are squeezed into a small enough region of space will become black holes.
But of course, you’d already know all this if you’d had a decent science teacher.