According to the Kerr-Newman model of a rotating black hole, there is a region just outside the event horizon where certain space and time vectors switch properties with each other. This is just mathematics, you understand, merely a quirk of the formulas — physically, nothing changes wildly until you get inside the black hole itself, and then who cares what happens? Double-deluxe chocolate-chip cookies could spontaneously spring into being and it wouldn’t matter to the universe outside. Reality may break down inside a black hole, but the effects never percolate back into our familiar space.

Just outside the black hole, however, if it’s rotating, if the model is correct, there is a region called the ergosphere where certain vector fields describing the flow of space and time do a flip-flop. When I was trying to understand what this meant, I told myself that places became moments and moments became places.

Think of that. Places became moments. Moments became places.

Years and years ago, I did my master’s thesis on black holes. In those days, I could have explained the math to you... but now I’ve forgotten it all. I look at the book containing my thesis and the only thing I remember is how hard it was to type all those equations. The meaning of the equations has dribbled out of my understanding a grain at a time, and now all I hold is this: just outside a spinning black hole, in a region called the ergosphere, places become moments and moments become places.

Think of that.

Kent State University entered the ergosphere at 12:24 P.M. on Monday, May 4, 1970. That was the moment the Ohio State National Guard opened fire on demonstrators protesting American involvement in Vietnam and Cambodia. Four students were killed; nine others were wounded.

Kent State ceased to be a place and became a moment. Like Hiroshima. Like Chernobyl. Kent State fell off the map and became thirteen seconds of gunfire on a warm spring day. And maybe it kept dropping down the gravity well, from the ergosphere straight into the black hole.