MURDER AND SUICIDE, RESPECTIVELY
by Ryan North

SCENE: Two scientists, Dr. Rosch and Dr. Nelson, are discussing experimental
results in a lab. A machine is at the centre of the room, wires leading
from it to various terminals at the edge of the room. A hand-made label
affixed to the machine by one of the technicians identifies the machine as
“The Machine of Death.”
Dr. Rosch: So the machine works. Given a sample of blood, it tells
you how you’re going to die.
Dr. Nelson: Yes.
Dr. Rosch: And we know this because we’ve done experiments on
lab mice and on ourselves. Once the mice started to die, we started
to get 100% accuracy. And with the passing of Dr. Chomyn last
week, it seems it works on humans just as well.
Dr. Nelson: Yes—we need more data points, of course, but there’s
no technical reason why it won’t work just as well on any mammal.
Dr. Rosch: Okay. This being the case, I have a question.
189 Murder & Suicide, Respectively
SCENE: Outdoors, Dr. Rosch and Dr. Nelson are strolling outside,
walking and chatting.
Dr. Rosch: So, I know I’m new here, and I wasn’t around for the
invention of the Machine. I’m necessarily approaching this from
an outsider’s perspective.
Dr. Nelson: Yes, but that’s fine.
Dr. Rosch: Right. So, here’s a thought experiment. We’re going to
assume that we’re ignoring the animal cruelty laws, we’re getting
around them somehow.
Dr. Nelson: Without jail time.
Dr. Rosch: Yeah. So, given that, we pick out a rat—let’s call him
Timmy.
Dr. Nelson: Okay.
Dr. Rosch: So we take Timmy the Rat and we decide that we’re
going to kill Timmy by braining him with a hammer.
Dr. Nelson: (surprised noises)
Dr. Rosch: Okay, so stay with me. We decide, we promise to ourselves,
that as soon as the test is done, we’re going to kill Timmy
the Rat by smashing in his skull with a hammer. We run Timmy
through the machine and it comes out “KILLED BY BEING
BRAINED WITH A HAMMER.”
Dr. Nelson: Well, not necessarily. It could be any number
of things. It might say “KILLED BY SCIENTIST” or “GOT
HAMMERED” or what have you. We don’t know why there’s such
variability, but there is.
Dr. Rosch: Right. But what all those predictions have in common is
that they all fit with being hit on the head with a hammer.
Dr. Nelson: Correct.
Dr. Rosch: Okay, so we take this prediction, read it, and then we kill
Timmy by smashing his head in with a hammer. Everything’s fine,
right?
Dr. Nelson: Right. Of course, if we decided to spare Timmy, then
the paper would reflect that. It wouldn’t have said “KILLED BY
BEING BRAINED WITH A HAMMER,” it would have said something
like “DIED OF OLD AGE,” or whatever.
Dr. Rosch: That’s fine. It’s crazy and creepy, but it’s fine. The predictions
are infallible. Sometimes they’re unclear or ironic, but
they always always come true.
Dr. Nelson: That’s correct.
Dr. Rosch: Okay. So what if we decide we’re going to kill Timmy by
smashing his skull in, but we’re not going to do it right away. We
run him through the machine and then put him in a box, where
he’ll have food and water and be cared for, and we leave him there
for a few months, and then we brain him. The prediction’s still
going to be hammer-related, yes?
Dr. Nelson: Most likely. Of course, the longer we try to keep him
alive, the greater the chance that the rat might die from some
other cause, a heart attack or something else we can’t control.
Dr. Rosch: But we can know that by the prediction: if it says something
like “HEART ATTACK”—something that’s inconsistent with
being killed by us with a blow to the head—then we know the rat
isn’t going to live long enough for us to kill it.
Dr. Nelson: I suppose.
Dr. Rosch: So let’s, say, take a sample of blood from Timmy and we
put him in this box, this life-support box. Then, we take this box
and we ship it overseas. Overnight. We ship it to Fred, say.
Dr. Nelson: Dr. Merry?
Dr. Rosch: Yeah. And we tell Dr. Merry that it’s coming, and then
when he gets the box, let’s say Timmy’s survived. We’ve instructed
Dr. Merry to open it up and kill the rat inside with a hammer at
precisely 11:59 p.m., which he does without hesitation.
Dr. Nelson: A stroke before midnight?
Dr. Rosch: Sure! For drama’s sake. Then, one minute later, at
midnight, we actually run the blood sample we took earlier
through the machine. What do you suppose it’ll say?
Dr. Nelson: Something about being killed with a hammer, of
course. It’s already done.
Dr. Rosch: Precisely.
(A beat.)
Dr. Nelson: So?
Dr. Rosch: You don’t see it? What if we could ship this box further
away? What if Dr. Merry lived thousands of light-years away, and
we could somehow get the box to him? If we set a time for him to
do the killing, and for us to run the blood through the machine
shortly afterward, then as soon as we read the machine’s prediction,
we’ve sent information faster than the speed of light.
(Dr. Nelson thinks for a second.)
Dr. Nelson: Well, it’s an interesting thought experiment, but we
can’t send things thousands of light years away, much less with precise
timing. The rat would be long-dead by the time it arrived.
Dr. Rosch: Sure. But if we could—
Dr. Nelson (interrupting): Even if we could, no information is actually
being transmitted. If Merry’s good at following our orders,
he’s going to kill the rat, yes? And we could expect this when we
sent the rat in the first place. Besides, we could run the test as
soon as we take the first blood sample, and we’d already know how
it’s going to turn out. So yeah, we’re getting information about the
future, but it’s not breaking any universal speed limits. The information
was always there, encoded in the rat’s blood.
Dr. Rosch: Hmm.
Dr. Nelson: But…but…
(He trails off, lost in thought. Dr. Rosch stares at him for a moment.)
Dr. Nelson: You’re just using one rat in your example.
Dr. Rosch: Yes. Just to make things easy to imagine. We could send
lots of rats—we probably would, in case some of them died for
whatever reason.
Dr. Nelson: Okay. Okay. What if we made, say, 100 of these lifesupport
boxes, and put a few rats in each.
Dr. Rosch: So, about 300 rats.
Dr. Nelson: Yes. And we don’t send these rats light years away or
overseas, we just...put them in storage.
Dr. Rosch: Each collection of rats in their own life support box…
Dr. Nelson: Right! We number each box. (excitedly) And a lab rat,
properly taken care of, lives for, what, 2–3 years?
Dr. Rosch (slowly catching on): On average.
Dr. Nelson: So we put these rats in storage and then, 2 years later,
or sooner, if need be...
(Dr. Nelson looks at Dr. Rosch, eyes wide with the idea.)
Dr. Nelson: ...We take them out.
Dr. Rosch (understanding): And we kill them.
Dr. Nelson: But we don’t kill them all with a hammer to the head.
We have a code.
Dr. Rosch: Each death means something different.
Dr. Nelson: It’ll be noisy—we can’t trust the machine to make it
clear exactly how each rat dies. But we’ve got more than one rat for
each letter. And if we choose the deaths carefully…we should be
able to minimize the overlap between predictions.
Dr. Rosch: A different death for each letter of the alphabet. Each
box equals one letter.
Dr. Nelson: We could send a message back in time to the point
when we first took blood samples from the rats.
(Dr. Rosch and Dr. Nelson stare at each other.)
Dr. Rosch: We’ve got to get to the lab.