He kept a black box on his desk, a small cube hooked to a large beeping monitor like an ECG, as though it were keeping alive a tiny and fragile animal. “What’s that?” she had asked, a visiting niece from another faculty, gesturing at the box and its attendant jumble of machinery.
“It’s a micro black hole,” her uncle had said. “It’s not very stable, and takes effort to keep it in place.” He tapped on something that looked like the unhappy union of a fire extinguisher and a pressure gauge. “This is the injector. It feeds the black hole matter so that it doesn’t evaporate away into nothing.”
“Black holes evaporate? You make them sound like puddles of rainwater.”
“They are surprisingly fragile when you get to know them better.”
So she’d asked him the question any normal person would have: why do you keep a black hole on your desk, even a miniature one?
“It’s a memorial. The Hawking radiation, see.” When she’d given him a blank look he’d just shrugged and said, “It’s a physics thing.”
She went home and looked up “Hawking radiation” on the Internet. On the fourth page of Google results she found notes for a lecture he’d presented to his first-year Astrophysics class. According to her uncle’s notes, black holes were not entirely radio-black as their name suggested, and actually emitted particles from time to time, losing mass in the process. He explained how it happened:
“Sometimes little miracles of nature happen, in the spontaneous generation of a particle-antiparticle pair. These particle pairs, irrevocably linked, are usually left to their twinned destinies.
But sometimes, at the event horizon of a black hole, disaster happens. One of the pair is pulled in and is lost, leaving its partner without a counterpart to annihilate with. The remaining particle, bereft, is left to wander the galaxy forever, doomed to its singular existence. And the black hole, having apparently emitted the lonely particle, must lose mass to preserve the laws of thermodynamics.
My wife, who is an English major, calls it the Shakespearean tragedy of particle physics. I can’t say I disagree.”
She remembered the way he looked at her aunt’s funeral, somehow smaller and sadder and greyer as he stood alone, away from the crowd. She remembered the way he spoke about his dead wife, the lively artsy girl to his quiet physics nerd, the extrovert to his introvert, the chaotic warmth to his aloof logic. She remembered what he said about opposites attracting. And that was when she realized that what he had said was wrong. It really wasn’t a physics thing at all.