Tess and Harry on the Dock
“What is an event horizon?” asked Tess.
“You know,” said Harry, “most kids your age ask where babies come from. You ask what an event horizon is.”
“I know where babies come from. Vivian told me.”
“Vivian told you?”
“She’s good at explaining things.”
“I explain things to you all the time.”
“You explain science to me.”
“Where babies come from is science.”
“It’s biology. That’s boring science. Physics is real science.”
“There’s no doubt you’re my daughter.”
“So, what’s an event horizon?”
“How do you even know that term?”
“I hear things.”
“An event horizon is the border of the gravitational influence of a black hole.”
“That’s not a very good explanation, Harry,” said Tess.
“Did it ever occur to you to call me Dad?”
“Did it ever occur to you to call me Tesla?”
“Fine. A black hole is a place where gravity is so strong that nothing can escape it—not even light. That’s why it’s called a black hole.
A black hole can be created when a dying star collapses on itself.
Its own gravity pulls it inward farther and farther until it is so dense it creates a black hole that just sucks everything in. ”
“Everything?”
“Everything that is inside the event horizon,” said Harry.
“So, an important safety tip is, if I see an event horizon, I should stay on this side of it.”
“I don’t think that issue is likely to come up in daily life.”
But Tess thought Harry was wrong. Tess knew there were things in life that would suck her in, black holes from which she’d never escape. What she didn’t know was how to recognize the event horizon.