passing familiarity
with the big topics helped me understand budget proposals and
STEWie run requests. This one hadn’t come up yet.
“Uh,” I began, having taken as long as
possible to finish the mouthful of pizza, both because I was
formulating my answer and because I was trying to figure out what
kind of crust I was eating. It wasn’t just plain old pizza crust,
that much I knew. Whole wheat? Rice? Drawing on vague memories of
my one college-level physics course, I said, “There is a box with a
cat in it, right?”
“Go on,” Dr. Rojas said, still in
professorial mode—not that he was ever far from it. He wasn’t much
of a conversationalist when it came to chitchat or personal
matters. Science was where he felt the most comfortable.
“And something either happens to the cat or
not, but it’s not clear which it is until we open the box.”
“Why isn’t it clear?”
“Because the box is closed. Can’t see inside
a shut box.”
Dr. Rojas shook his head. “No, that’s not
it.”
“The box isn’t closed?”
“It is, but that isn’t why we don’t
know what happened.”
“Why, then?”
“Because we can’t know what happened.”
“What do you mean? Why can’t we know?”
“Because we haven’t looked.”
If I had been having the conversation with
anyone but Dr. Rojas, I would have at this point assumed they were
putting me on.
“I think I better draw a diagram.” Dr. Rojas
took a Sharpie out of his shirt pocket and vaguely glanced around
the table for something to write on. All the napkins in the place
were cloth and too pristine to be used for sketching, so I tore a
page from the notepad in my shoulder bag and handed it to him. He
folded it in half and drew a large square. “Here is a steel box.
Add a small amount of a radioactive substance and a Geiger
counter…a hammer…and a vial of poison. Cyanide.” He sketched all of
those in, then added, “And one cat,” and drew a stick figure of a
cat.
“With you so far,” I said.
“Good. The radioactive substance is such that
there’s a fifty-fifty chance that one of its atoms will decay—emit
radiation—in the first hour. If it does, the Geiger counter
registers this and releases the hammer, the hammer smashes the
vial, and cyanide leaks into the air, with unfortunate results for
the cat. If there is no decay, nothing happens to the cat.”
The professor paused here, as if expecting me
to say something at this point. I tried to rise to the occasion.
“So, in summary: it’s a coin toss whether the Geiger counter,
hammer, and vial will be nudged into action, which would spell bad
news for the cat.”
“So what can we conclude?” he prodded me.
I glanced down at his sketch. “Uh…that the
cat might die? Also that this is not a particularly nice
experiment.”
“According to the Copenhagen interpretation,
a quantum system exists in all possible states simultaneously until
observed. It’s not that we don’t know what happened until we look,
it’s that the matter is settled—has an atom decayed?—only when we do look. Therefore, by extension the cat is both alive and
dead—or, if you prefer, neither—until the box is opened.”
I mulled this over. “Nothing is settled until
we look.”
“Exactly.”
“But what does that prove?” The pizza wasn’t
bad, I decided. It just tasted different. I washed it down with
iced tea, as the waiter had scrunched his nose at my attempt to
order pop. Coke and Pepsi were not served at the Faculty Club. “I
mean, the cat’s not really both alive and dead until we open
the box. It can’t be. It’s like that old puzzle: if a tree falls in
the woods and nobody’s around, does it make a sound? Of course it
does.”
“That was Schrödinger’s point—how absurd
quantum concepts are when linked to the everyday world, as
represented by the cat. It’s all very well to say that the quantum
world is just a cloud of probabilities…but that doesn’t seem to be
the case in the
Dean Wesley Smith, Kristine Kathryn Rusch
Martin A. Lee, Bruce Shlain