Last week I read Quarantine (Greg Egan, 1992), a science fiction novel that explores one of the more vexing conundrums in basic physics: the measurement problem. Egan’s stories (novels and shorts) often explore some specific aspect of physics (sometimes by positing a counterfactual reality, as in the Orthogonal series).
In Quarantine, Egan posits that the human mind, due to a specific set of neural pathways, is the only thing in reality that collapses the wave-function, the only thing that truly measures anything. All matter, until observed by a mind, exists in quantum superposition.
Unfortunately, it’s difficult to explore how this ties into the plot without spoiling it, so I’ll have to tread lightly.
FWIW, I’m a fan of hard SF, and of Egan’s work in particular, so I was predisposed to enjoy the story (and I did). As with a lot of hard SF, it’s more about the exploring the ideas than about plot and character.
I have no pretensions that I’m a literary critic. I’m just an avid reader who likes to kick back and enjoy a good story with interesting ideas. Egan almost always delivers on that front. I’m in no position to judge the quality of his writing.
If I have any criticism at all, it’s that sometimes his stories end in a way that I find unsatisfying, usually because the scope of the story suddenly expands into something that reaches for grandiose.
(His novel Distress hit me especially hard that way. I rather disliked how that one ended.)
The measurement problem is a quantum mechanics question involving how potential futures become real in the present.
A question that expresses that problem involves the infamous cat of Schrödinger: what causes said cat to be quick or dead?
Specifically, what counts as a “measurement” of the radioactive atom?
When a decay particle hits the detector, is that enough to collapse the superposition between the atom decaying and the atom not decaying?
There are billions of atoms in the detector; does the decay particle’s interaction with them collapse the wave-function? (My guess, along with many others, is yes, this is where the collapse happens, but no one can say exactly why. I lean towards a theory that involves gravity.)
How about the circuitry the detector activates to smash the poison vial? That larger system has many times more atoms; is it enough to collapse the wave-function?
How about the cat? Is a living creature enough? Does it have to be a human?
In Quarantine, it requires an observer with a brain. During a key info dump, one character says:
“Ah. Existing computers, definitely not. Collapsing the wave function is a specific physical process — not an automatic by-product of a certain degree of intelligence, or self-awareness, or whatever — and computers simply haven’t been designed to do it … although no doubt some will be, in the future.
“As for cats … my guess would be that they do it, but I’m not exactly an expert on comparative neuro-physiology, so don’t take my word for it. It may be years before anyone gets around to finding out exactly which species do and don’t.
The speaker goes on to mention questions about how the trait evolved and what the universe was like before the trait evolved.
Note that, for Egan, a single human looking (or the cat itself) really does collapse the wave-function. It is not the case that the system is now in superposition relative to someone outside the lab who has not observed anything. (In contrast to certain thought experiments that claim this is true.)
Quarantine starts off as private eye story.
The plot begins in 2067 when Nick Stavrianos, former cop, now a PI, is hired by an anonymous client to find Laura Andrews, who vanished mysteriously from a special needs care clinic.
Laura was born with severe brain damage — large parts of her brain’s wiring aren’t connected. Her motor functions are largely intact, but the experts attending her say she understands the world at about the level of a six-month-old child.
When the story begins, Earth has been cut off from the stars since 2034 by The Bubble, which suddenly appeared out beyond Pluto (at about twice the distance to the ninth planet).
The Bubble, which has all the characteristics of a black hole event horizon, hides the stars and locks humanity inside. No one knows the how, why, or who, of The Bubble.
Nick comes to find out Laura has “vanished” from her room twice before.
The first time she was found on the grounds of the clinic, the second time a few kilometers away. In both cases, “just wandering about, with the same bland dumb innocent expression on her face as always.”
This third time, she hasn’t been found, and Nick comes to discover that she was, indeed, kidnapped this time.
Why she was kidnapped, what she means, who’s involved, and what The Bubble has to do with anything, are all points that would spoil the story if I got into them.
I wasn’t disappointed by the ending although it does get a little vague once the story is told and Egan needs to wrap things up. (There is some debate about what actually happened at the very end.)
I’m not sure what else would have made it any better, though. Idea stories don’t have the driving narrative arc that demands a satisfying ending.
[See the novel’s Wiki entry for more plot details if interested.]
By 2067 technology has progressed to using highly modified Endamoeba to carry nano-machines from the nasal cavity into the brain where the nanites perform engineered “mods” on the brain’s wiring in order to grant new skills.
Nick, a former cop, has a series of special mods: “P1 can manipulate the user’s biochemistry, P2 augments sensory processing, P4 is a collection of physical reflexes, P5 enhances temporal and spatial judgement, P6 is responsible for coding and communications…”
And P3 “eliminates distractions and makes it easier to focus the attention” — very useful for surveillance or guard duty.
Nick has a variety of other mods to help him be a PI. He can, for example, receive encrypted messages that only his brain can decode. The contents of such a message appear as a memory to Nick.
The story also gets into loyalty mods, which can not just enforce loyal behavior, but make the subject desire nothing more than to be loyal and to resist any attempts to undo the mod.
These mods are generally permanent, anyway. The nanites code the changes with special “keep off” proteins that any other nanites are required to respect.
(There are also (illegal) “puppet” mods that allow someone to control a person like a puppet.)
Other than that and the ability to re-shape the body as easily as the mind (also using nanites), technology is pretty much as we know it now.
There are no flying cars or laser weapons (let alone transporters or replicators). There don’t appear to be conscious computers, and we haven’t solved consciousness to the point of uploading (a frequent part of Egan’s work).
For Apple iBooks, I gave it four stars (out of five). In my personal rating system, I give it a medium Ah! (neither strong nor weak).
Definitely recommended for Egan fans and perhaps hard SF fans in general. Also a fun read for those interested in quantum mechanics as it really does explore some of the inherent issues.
I should point out that Egan (on his website) says:
My 1992 novel Quarantine centred on a tongue-in-cheek, science-fictional resolution of that controversy, with a hypothesis that was chosen solely for its technological and existential ramifications, not because I considered it plausible. I said as much in interviews at the time. However, the world is full of misinformation about quantum mechanics, and while nobody would mistake Quarantine for a textbook on the subject, over the years I’ve often looked back and winced at some scientific flaws in the novel that go beyond the mere implausibility of its central premise.
So just take it as a fun read with some interesting ideas.
Stay uncollapsed, my friends!