Heads, Greg Bear

This is a reread of something I must have first (and last) read 30 years ago. It's novella length, but its inventiveness and audacity have kept it memorable when other titles have long since faded away. So it was interesting to see if its legacy holds up.

Entirely Moon-set, it's narrated by Micko, a junior member of a family company (or "Binding Multiple", BM) charged with managing the affairs of his brother-in-law William's low temperature laboratory, the Ice Cave, which is teetering on the brink of an Absolute Zero breakthrough. With excess cooling capacity available, Micko's sister, and William's wife, Rho, brings a pet family history project from Earth: a mixed batch of cryogenically frozen heads from the early 21st century. While effectively dead meat, scientific advances convince Rho the heads can be "read", potentially opening a link to the great-grandparents who founded their BM. But the arrival of the heads triggers unexpected friction with other BMs, including strong pushback from the Moon's president, a member of a religiously-affiliated BM. Micko and the wider BM are caught off-guard by this hostility, until he guesses - correctly - whose head accompanies those of his great-grandparents, triggering revelations but with tragic consequences.

… And it's still excellent. Its length definitely keeps it punchy, but it's really impressive just how much Bear squeezes in. I've not even mentioned the Quantum Logic (QL) thinker - the AI controlling William's experiments - above, but its cool, alien pronouncements are a real joy. And I'm even more impressed on rereading just how vicious it is in its takedown of its thinly-veiled proxies for real-world Scientology. Bear's Logologists are transparently stand-ins for L. Ron Hubbard's cult, and he’s brutal in laying bare the reality of its formation and malevolent perpetuation.

If I had to criticise it at all, the denouement is a little raced-over compared to the preceding. But, otherwise, it stands the test of time, and is easily worth the hour or two needed to read it. It works both as a hard sci-fi yarn on Absolute Zero, and as a devastating strike on a vexatious and malign cult.

The Space Between Worlds, Micaiah Johnson

There is a multiverse. The histories of several hundred universes are close enough to our own to permit travel between them. But jumping to a world in which you exist is invariably fatal - the multiverse is unforgiving in this regard. As a result, the most valuable travellers are those already dead in other worlds. Something that's all too easy for the poor and dispossessed in our ruined post-apocalyptic world.

What an excellent debut novel! Every part of it works brilliantly - from its well-drawn (and frequently-duplicated) characters, through the slow-reveal of its setting, to the unfolding of its satisfyingly twisty plot. The author takes what's now become a familiar trope - the parallel world - and spins off their own fresh version, complete with duplicate-prohibition, a travellers mythology of how Mother Nature enforces it, and a zeitgeisty meditation on a class- and race-stratified society.

Early on, I had a feeling of overfamiliarity with its post-apocalyptic dystopian future, but it didn't take long to reveal itself as something more unique, and cleverly so to boot. In particular, its use of duplicated characters - some very familiar between worlds, some very different - is excellent. Both in illuminating the vicissitudes of life's paths, and making for a wonderfully finely-tuned plot as the narrator, Cara, leverages her growing knowledge of the multiverse to topple the tyrant that rules the one she has come to call home.

For sci-fi, it's worth remarking that the writing is well above and beyond too. It's sparing but hits the sweet spot of world building while avoiding "Basil Exposition". Ditto, its characters are far more subtly drawn than the genre typically manages, which works particularly in a plot that requires its actors multiple shades.

Overall, simply excellent. (And a novel that practically screams "make me into a film".)

Old Man's War

Old Man's War, John Scalzi

After the success of another Scalzi novel, The Collapsing Empire, this one sounded like a nicely offbeat and interesting read. A story about an old man who, unexpectedly alone in retirement, signs up for colonial military service to fight for humanity on the High Frontier. In execution, it overlaps rather a lot with Heinlein's classic, Starship Troopers, with a rather straightforward narrative focusing on the training and early missions of a group of "new" recruits, and wrapping up on a big mission. However, it fell down hard for me largely because of two consecutive chapters late in the book that undid all of the preceding solid work. One gave a "clever" explanation for the unpinning science (it's all driven by the "many worlds" interpretation of quantum mechanics) that obliviously undercuts any reason for getting invested in any characters or events - since these would (implicitly) play out differently in another universe. While the other dealt with the growing qualms that readers (this reader anyway) might have with the novel's colonialist militarist vision of future human life by telling them (via the main character) to get over it. So much for a modern retelling of Starship Troopers that undercuts its predecessor's fascist tendencies. My good will evaporated after reading these, and didn't return.

Source Code

Playing a little like an action version of 1990s TV series Quantum Leap, the latest feature by Duncan Jones, Source Code, manages to blend time travel, romance and (faux) quantum physics into an extremely pleasing thriller.

Its central protagonist, Captain Colter Stevens, a military pilot whose last memory is of a helicopter crash, awakes on a train to Chicago seated opposite a mysterious woman who appears to know him. Completely disorientated, he flounders through the train, discovering along the way that the face in the mirror is different from his own just before the whole train is destroyed by a terrorist bomb. He then awakes in darkened chamber where he is cagily informed that he is on a mission to discover the identity of the bomber, a task that exploits an experimental technology, the Source Code of the title, that allows him to relive the last 8 minutes of the life of a passenger on the train. Repeatedly "sent back in", Colter gradually uncovers the evidence sought by his military handlers, but he also exploits the technology to discover more about his own fate outside the Source Code. He also forms a connection with those people he meets through the Source Code, and ultimately uncovers a transformational secret about the technology unknown to its stern and ambitious creator.

Another clever gem from Jones, IMHO. Not one that will appeal to everyone I suspect, but it pushed a number of my buttons: science fiction, quantum mechanics, consciousness, noble self-sacrifice, etc. It even threw in a cute, if rather perfunctory, romance. The only thing I thought that it got slightly wrong was in the way it handled its central conceit. Basically, it borderline fluffed it, and almost made something high concept which seemed straight out of a Greg Egan novel seem like a glossed-over MacGuffin. A few more words from Jeffrey Wright's scientist, perhaps even ones minted by Egan, and it would have cruised over this. As it stands, the film's final revelation will for many people seem like a tacked-on happy ending instead of what it actually is, a rather clever variant of Many Worlds. Still, being versed in Egan, this didn't spoil it for me. I was genuinely impressed that a film, an action film, was able to make something of ideas similar to those that populate his books, and still find space to make me care about its characters.

Grade: A (low +3 on the Leeper Scale)

Free will, 2

Ding-Ding! Round 2.

APM, a long-standing combatant in my battle against my own misunderstanding, has responded to my first salvo.

First your question of why the feeling of free will should arise through evolution. Can we rule out the fact that our apparent 'free will' is a bonus from a more important evolutionary adaptation. I seem to remember discussing this with you at the end of a long pub visit some time ago. Speaking as a totally ignorant non-biologist, I could suggest that a key aid in survival is imagination, the ability to realise that rubbing the sticks together produces something more useful than splinters and that a sharpened stick is useful for both catching fish and despatching a competitor. Might it be that what we perceive as free will is actually just a consequence of a sophisticated ability to assess the environs and work through potential dangers, benefits and solutions. It might be argued that the broader ranging, or free-er the calulations the better benefit.

I like this idea. If I understand correctly, you're suggesting that the phenomenon that we perceive as free will is related to whatever mechanisms drive imagination. I guess that some "imagination subroutine" generates ideas, presumably by sifting and combining memories, then somehow evaluates them (a "simulation subroutine"?), before culling them down to the "best idea". And that, since it involves selection and "choice", this process has an associated emergent phenomenon that we perceive as free will. In this way, a reasonable connection can be drawn between a deterministic^[1] algorithm for selecting novel behaviour, and the associated specific perception of free will.

While I can see the connection that you've drawn out there, I'm still hazy on whether it necessitates such feelings of freedom. But it could go some of the way to explaining why certain deterministic processes have very particular emergent phenomena associated with them. I do still find it hard to swallow that even such goal-oriented processes would generate a non-interactive perception of such specificity that cannot feedback onto them. But that's the rub I guess.

If I can get all metaphorical about it for a moment, how's about this: In the conventional view, the cogs and wheels of strict materialism manifest themselves both as external behaviour (i.e. I have a cup of tea) and a perceptual "projection" (i.e. I experience myself having a cup of tea). But this latter part is coupled one-way and does not feedback on the cogs and wheels.^[2] In my non-conventional (and possibly deviant, quasi-dualist) view, the cogs and wheels of strict materialism manifest themselves in the same way, but the perceptual "projection" is somehow (and this is a huge "somehow") coupled two-way. Now, since in the former case the "projection" is solely an output, it's not obvious to me that evolution would shape it to such high precision. But if it somehow feeds back onto material events, then it's easy to see evolution making it as focused and accurate as our perceptions are.

In this sense, much as with my misguided take on quantum mechanics, I guess I'm arguing that my conception of free will relies on a form of hidden (at this time) variables. I don't doubt that a (large?) part of behaviour in all animals operates at a sub-free-will level, for instance reflex actions. But part of my subjective experience suggests that there's more to it than this, and that aspects of perception that are essentially coercive (pain, pleasure) don't make a lot of sense if the coercion is only operating on something that cannot respond to it. Admittedly, there's still the possibility that what we perceive as pain and pleasure is merely an outcome of deterministic feedback loops in our heads, but my objection to this is that they're pretty refined for things that, essentially, don't do anything.

My hunch is that evolution, through the production of deterministic brains that process information into detailed representations of the real world, has somehow accessed hidden variables that currently lie outside our understanding of the material universe. These variables permit functionality beyond that attributable to atoms and electrons. But having just written that, it sounds like a load of old tosh and the road to mysticism to me.

This leads on to another of your points, regarding why we might have developed pain and pleasure sensations. This seems to be assuming that our conscious is outside our biological entity. If our consciousness is just a rather sophisticated computer then it is no surprise that we are aware of our senses relaying important information to it as it has clearly been developed to take a longer view than a simple reflex action.

Be gone Dualist Demons! ;-) Yes, I suppose that I am arguing for a more complicated relationship between matter and mind. Part of the problem in all of this is that I don't believe we have any good ideas about what consciousness is "made" of. It isn't obviously made of atoms, nor is it anything that seems attributable to the various force fields that pervade us. It clearly isn't "contained" within a single "master neuron", but if it's a distributed phenomenon, what substrate is it spread across? That said, it's also obvious from a wide range of evidence that, whatever it is, it's intimately related to the organic material between our ears. Such that, among other things, injuries in specific areas affect it in predictable and catastrophic manners.

However, if we assume that consciousness isn't free (i.e. two-way interactive), and that it simply represents the working out of conventional deterministic processes, I don't think it follows that it's "no surprise" that it contains such well-honed perceptions such as those provided by our senses. A one-way connection between neural physiology and consciousness would effectively make the latter invisible to evolution. But I appreciate that sentence does take something of a dualist perspective on the nature of consciousness!

Finally, just to clarify something, I'm uneasy with the argument that we don't know all of physics yet so there might be another explanation for free will as it seems to dodge the question. Your comment on it being extremely unlikely to have arisen by coincidence sails a little too close to concerns over the evolution of the eye too perhaps?

It's a fair cop. Falling back on as-yet-unknown physics is a weak argument. But I do think (possibly erroneously) that our perceptions lie outside of what we currently know about physics. And I don't just mean that we haven't ironed out the details, I mean that there does not yet appear to be anything like a clear mapping from the observable quantities of physics (particles, waves) to what goes on in our heads. Putting it flippantly: what is my pain (pleasure/love/hate/joy/fear) made from? I don't doubt that it's made from something material, but I don't think that we have a good handle on quite what yet.

Re: Eye evolution, I do hope you're not suggesting I've gone over to the Dark Side! ;-) Actually, re-reading the above, I do sound a bit like some counter-revolutionary dualist. Time, perhaps, to stop digging ...

---

[1] When I say "deterministic" here, I don't mean to exclude stochastic processes. I really just mean processes whose outcomes are not guided by anything that science is unaware of (if I can double-negative myself). Either ones that are completely deterministically driven by past events and a system's state, or those which are completely stochastic and independent of history or the current state of the system. Basically, not "free will" which, as conventionally understood, is some kind of additional "quintessence" that can independently (i.e. non-deterministic) and purposefully (i.e. non-stochastic) drive a system.

[2] In fact, since we have no good idea where this "projection" is, or even what it's "made" of, there are reasons to get suspicious of this picture from the get-go, but I don't want to get back into that for now. Not least because I don't have any good ideas about this either.

Free Will, 1

The other week BS engaged me in a further discussion of free will, but we came unstuck largely because my descriptions of my viewpoint are opaque and/or incomplete. So I'm going to try to outline them more fully here so that we can have another go.

First, though, I should just clear up why I'm interested in this at all. It certainly has no obvious connection to my professional interest in things planktonic. Instead, it just boils down to a desire to know what's right (= maximally accurate; I'm a scientist after all) about the most immediate of our impressions of the world. I don't actually care if I'm wrong in my views below, but I would like to know what the right (cf. clarification immediately above) answer is. As it happens, I don't expect a right answer to appear in my lifetime, but it would still be useful to know if (or where) my reasoning is completely off the mark.

Anyway, it actually might be best if I first characterise (potentially mischaracterise) what I understand of the mainstream alternative view. Essentially, this boils down to machines such as ourselves (and I'm happy to see us as machines) being the sum of stochastic and/or deterministic processes and nothing else. So, any appearance of freedom in our actions is actually the outcome of nothing more than vast numbers of atoms interacting according to the boring rules of classical physics or the random whims of QM. Of course, a purely deterministic system with no random elements (which, ironically, I believe the universe to be) can be sufficiently complex to prevent prediction, but such chaos is still fundamentally dull determinism. Essentially, a pachinko machine, however complex, is still a pachinko machine.

In this view, the currently known laws of physics are taken at face value, and since there is nothing in them to allow other influences on the material universe, that means there really is nothing out there that permits popular conceptions of free will. Of course, I would further argue that said currently known laws also have nothing in them to in any way explain my subjective experiences, free or otherwise. By this I mean that the qualia that I experience as an everyday fact of life are (as far as I understand) not included in any current model of physics. Of course, it's possible that we just don't yet see how they fall out of conventional physics, but they seem of such a different quality to other phenomena that I don't much rate this line of argument.

Instead, I interpret these latter points to mean that our knowledge is seriously incomplete, and that there are aspects of physics of which we are still ignorant (possibly even unknown unknowns). For instance, the existence of hypothetical "materials", such as the exotically-titled dark matter and dark energy, and our near-complete ignorance of their nature, is strongly suggestive of such gaps. Not, of course, that I would ascribe our subjective experiences to these alien properties (cf. His Dark Materials), since that's far too "god-of-the-gaps" for me to countenance. My argument here is instead that these are simply illustrative of the incompleteness of current physics, which, I'd add, is still stubbornly incomplete (and un-unified) even on the ostensibly well-understood topics of QM and GR.

So, by way of summary, I would caricature the mainstream interpretation of the world as follows:

• At root, all processes are either stochastic (QM) or deterministic (classical) in origin
  
• These uninfluenceable origins are then filtered up through, or compounded by, a long series of largely deterministic (classical) processes to give an extremely diverse set of outcomes (the richness of the universe)
  
• One of these outcomes are the suite of qualia that we each subjectively experience, these are essentially emergent phenomena from underlying physical processes
  
• Our (whatever "our" actually means here) relationship with these qualia is one of complete passiveness, with an influence similar to that of a cinema goer on the film being shown
  
• However, one of these qualia is the perception that, unlike the cinema goer, we are free to influence events, but this is merely another facet of the emergent property that we each experience and label as consciousness
  

Anyway, this is all just background to soften up the territory for my resplendent arguments to wash over and conquer. Obviously.

While I naturally accept almost all of the above, my view is that a number of features of our subjective experience are glossed over in this treatment. I don't, for even a second, have any underlying explanation for these features, and I completely accept that I'm arguing from a position of theoretical weakness. In this regard, my position is not one that easily survives the application of Occam's razor. Worse, it evokes the spectre of dualism, and effectively puts me into compromising positions with a number of other dubious propositions. But I'm getting ahead of myself, or possibly just presenting my caveats ahead of time such that my main arguments are the last things read.

My stance is primarily a biological one, grounded in a handful of features that I find hard to ascribe to an utterly passive emergent phenomenon. First of all, and I've already made this point, I don't think that we should dismiss out of hand the difficulty of squeezing subjective experience into mainstream scientific understanding. This stands regardless of whether the rest of my argument does, though I'd cheerfully agree that my view has as much trouble with this as the mainstream does.

Secondly, our perception of possessing free will is an odd thing. Many (if not most) people take free will at completely face value, to the extent that this whole article will seem absurd (second only, perhaps, to the mainstream view of complete denial). Now, my point here is that one of our qualia is a highly developed sense of being in control. If we really aren't in control, then this is a singularly strange conviction. Particularly so when one considers how it might have evolved. If I absolutely cannot influence the world, then why on Earth has my mind been shaped so that an emergent property of it is the distinct impression that I can? Simply put, I clearly don't need this perception if I really can't control things. What's the worst I can do? Have a pointless metaphysical sulk?

Thirdly, there are a number of further aspects of our perception that exist to channel our behaviour in very particular directions, and which are clearly evolved. For example, we have qualia of pain and pleasure which strongly impose themselves on the rest of our perception, and encourage us to do things that, biologically speaking, are sensible. Pain obliges us to avoid situations that compromise our survival, while pleasure rewards us in situations that are beneficial, if not for us, then at least for the genes which built us. Again, the absence of any actual free will to control events would make these very strange adaptations.

By way of summary, it seems improbable to me that evolution should shape our subjective experience to include these sorts of features if they then play no role in subsequent events (beyond some sort of cinema experience for an ill-defined "self"). If consciousness truly were an entirely passive emergent phenomenon, it seems extremely unlikely to me that it would be such a faithful representation of the world, one which included carrots and sticks, and one which explicitly conveys the feeling of control. These bells and whistles would simply be utterly superfluous, so not something evolution would be able to finesse.

Of course, it could perhaps be argued that all of these aspects of consciousness could still be a by-product of the unconscious activity of deterministic processes in our brains. By firing in response to particular stimuli, neurons coincidentally create an emergent property which feels to us like consciousness (and, of course, actually is us). However, as before, I'd argue that, if anything, such a coincidental phenomenon would be unlikely.

Anyway, I'll pause here rather than drag this super-long post out much further. As I noted right at the start, my primary interest here is in being right. Not in the sense of the particular ideas expressed here being right per se, but more in ensuring that I'm not labouring under some misapprehension when the truth (well, a closer approximation to it) is already to hand. I'm not so wedded to the the thoughts above that I won't throw them over for a more complete explanation of our subjective experiences, but my understanding of "the opposition" is that it, too, lacks some key pieces of the puzzle. Unless I'm misunderstanding it, in which case I hope that someone will put me right.

Many worlds and many minds

After my last few reads of him, I keep saying that I'm going to give Greg Egan a bit of a rest because reading his mind-bending novels is clearly above my pay grade. They're really good, but they're hard, hard reads (in the science fiction sense; we're not in the misery genre here). However, since it's recently been Birthday-Christmas season, I've received quite a pile of new titles, two of which were written by Mr. Egan. So, in order to free up some book shelf space, I'm duty bound to tackle him again. That said, it's a little easier this time since Axiomatic is a collection of Egan's short stories.

The collection is Egan's first, and consists of stories published between 1989 and 1992. Pre-blog, I read his later collection, Luminous (which was also a present from C), and it definitely confirmed him as a must-read for me. The stories here range extremely widely in their subject and intent, although plasticity of mind, body and reality is a recurring theme.

Much as with his novel Quarantine, he visits quantum mechanics in the great opening story, The Infinite Assassin, inventing a special assassin who travels between universes to kill those with similar powers but who are intent to reshaping reality to suit themselves. The Hundred-Light-Year Diary imagines a future where everyone's daily lives are mapped out by diary entries ostensibly from the future. In The Caress, a detective who discovers a human-cheetah chimera is kidnapped to pose in a megalomaniac's reconstruction of Fernand Khnoff's most famous work. The widower protagonist of the eponymous Axiomatic takes an implant to "rewrite" his objections to capital punishment so that he can understand, and avenge, the murder of his wife. Meanwhile, the mind of the narrator in The Safe-Deposit Box flits nightly between different bodies, and uses the titular box to store the scraps of information he collects while unravelling his mysterious condition. Switching to electronic minds, Learning To Be Me concerns jewels, the artificial replacements for human brains that develop alongside them, and the conundrum of where consciousness really lies. The Moral Virologist is a fundamentalist with a training in molecular biology who creates a plague to target the "immoral", but his accuracy is blunted by biology's loopholes. In Closer a couple desire to know each other so completely that they trade bodies and even merge minds, but is perfect harmonisation really what lovers need?

As the selection above suggests, the collection is full of exotic treatments of biology, consciousness and reality. Several of the stories are simply jaw-droppingly imaginative and clever in the development and expansion of their central ideas, and Egan is almost uniformly excellent at wringing the most out of the worlds that he briefly creates. There are a couple of less successful stories, but even these contain the germ of a good idea.

More generally, I find that short stories suit Egan better than full-length novels. While their truncated page-count means that they lack the worked-out detail that his novels contain, this works in Egan's favour since he's forced to rein in his tendency to digress into full-throated dissections of physics. Also, since characterisation generally isn't a strong point of his novels, the necessary abbreviation of the occupants of his short stories obscures this weakness.

Overall, an excellent collection of stories. Not quite as good as the later Luminous I'd have said, but perhaps not surprising given that this contains his first forays into science fiction writing. And undoubtedly a more gentle introduction to Egan's obsession with the nature of reality and consciousness than his more gung-ho novels. A definite incentive to track down more of his short fiction.

Quarantine Mechanics

Perhaps I should have learnt from my most recent experience of him, but I was sufficiently intrigued by the backcover blurb that I couldn't resist checking out Quarantine by the Australian novelist Greg Egan.

The novel is set in the late 21st century, 33 years after the appearance of the Bubble, a strange, impenetrable barrier that isolates Earth's solar system from the surrounding space and which obscures the stars. While the physics, purpose and creators of the Bubble defy explanation, many ideas have been advanced for its appearance, and it has inspired violent religious cults that have rocked society with terrorist acts.

Nick Stavrianos is a former policeman, and a widower because of one cult's actions, now operates as a private detective in Australia. Originally because of his work, but now additionally because of his loss, he is augmented with mods, nanomachine-delivered modifications to his nervous system that manage all facets of his life, from those that permit direct technology interfacing to those that allow him to control his perception and moods. One mod, Karen, even creates a visual and auditory hallucination of his eponymous dead wife, one which advises and chastises him in equal measure.

Nick's latest case concerns the disappearance of a 32 year old patient from a secure facility for the mentally-handicapped. The woman, Laura, doesn't appear to fit the profile for a kidnapping victim, and is only missed by her surviving family because her vanishing may represent a financial reward for the facility's negligence. Nick's initial investigations uncover little beyond Laura's predisposition for brief periods of disappearance, but as he delves deeper he uncovers an electronic trail of evidence that points to her illegal transport to the north Australian city-province of New Hong Kong. Following this leads Nick to infiltrate the corporate headquarters of Biomedical Developments International, BDI, where he briefly encounters Laura before he himself is captured.

Waking up, he finds that his portfolio of mods has been extended with the addition of a loyalty mod, Sentinel, that makes him a willing slave of BDI. With his particular background, he's of use to them as a security guard in a project they're undertaking based on their analysis of Laura. Her ability to escape secure accommodation is just the tip of an iceberg of talent that BDI have reverse-engineered into a new mod, Ensemble, that breaks new ground in quantum mechanics (QM). By interfering with normal human brain function and preventing wavefunction collapse (via a version of "consciousness causes collapse"), the mod allows its user to "smear" their reality, such that they can choose the outcome of events from the wide array of possibilities presented by the quantum nature of reality. In this way, the user operates somewhat like a quantum computer in which the "correct answer" to a problem is found by sifting all of the possible subjective experiences of the user, and then collapsing the user's wavefunction so that only this one answer is made objectively real.

Though this all seems impossible at first to Nick, the demonstration of Ensemble's power by the researcher/test subject Po-kwai, convinces him of its reality. But its potential for misuse, and its possible connection to the Bubble, gradually forces him to act despite Sentinel.

The above description does something of a quantitative disservice to the novel. The conventional part of the novel, that bit prior to the arrival of QM, only makes up about a third of the book, while the crazy-ass, reality dysfunction of Ensemble requires the final two thirds of Philip K. Dick-esque mindfuckery. To be fair to Egan, his flavour of reality distortion is quite unlike that of PKD. The latter's seemed entirely drug-fuelled, and allowed his novels to forsake coherence and conventional narrative structure, instead replacing them with a heightened sense of paranoia and alienation. Which is why, for all of the clever ideas that sometimes underpin PKD's books, I can't really stand them. By contrast, Egan's deconstruction of reality is firmly rooted in one of the many interpretations of QM, and is both cleverly thought-through and logically coherent. Much to Egan's credit.

However, it makes for an extremely confusing and challenging read. I said something similar of the last of his novels that I read, but the problem here is of a much greater magnitude. In Schild's Ladder, the difficult bits could be skipped since they didn't prevent the reader from generally getting the jist of the story. Here, after an initially conventional science fiction backstory and opener, the novel goes off at the deep-end to such a degree that it's difficult to make head-or-tail of a large and significant chunk of what's going on. While Egan is pretty descriptive (generally in a good way), I don't think I really got to grips with Ensemble until I started this review and had to think about what it was I'd just read. None of which makes for a positive prognosis for most readers I'd imagine. Those with a better grip of QM will probably make better weather of it, but I found the ideas and descriptions so dense that, at times, they passed through me as if I was skim-reading the book.

Aside from the difficulty of hurdling a key plot device from the deeply non-intuitive world of QM, the delving into Ensemble gradually pushes the novel's early concerns for the Bubble and Laura far into the background. While there are late digressions to tackle both of these, Egan's attention has clearly switched to thinking through the implications of his QM conceit. By the end, I was pretty sure that Laura and the Bubble were connected (a fact that I had actually immediately grasped from their close ages), but the "smearing" of reality left things considerably more opaque than one would desire.

One of the odd things about Quarantine's jack-knife turn into the ultimate nature of reality, is that it sort-of undoes what's an otherwise interesting future that he's carved out. From the get-go the idea of the Bubble is a fantastic one, and one that Egan runs with for a while. The consequences, political, philosophical and theological, of the sudden imprisonment (or is it protection?) of humanity are all touched on, and I was genuinely surprised that Egan largely left them to twist in the wind. Similarly, in introducing mods to the reader, he opens the reader to the idea that subjective experience could be as easily modified as a computer's screensaver. The early descriptions of Nick's use of his mods are quite brilliant, from the controlled use of his old police mods to focus on the case, to the disruptive appearance of Karen and its subtext on his (mis)handling of his own grief. But all of these carefully constructed details feel somewhat sacrificed when Egan hits his QM-stride.

So, again, a mixed experience from Mr. Egan. Despite the difficulty navigating the deeply counter-intuitive core of the novel, and with Egan's increasing disinterest in the book's early plotting, it's hard not to be drawn in and impressed by just how far he pushes QM as a narrative device. Even if it does seem as if he ultimately lost his way in telling the tale. I'll be getting back to him at some point, I've no doubt, but I'll leave him be for a bit just to give my head a bit of a rest.

Hard, Harder, Hardest

After a short break from science fiction, I've returned with a vengeance: the ultra-hard, hard science fiction of Schild's Ladder by the Australian author Greg Egan.

Schild's Ladder is set in the distant future, where the giants of 20th century physics are now quaintly described as "the ancients". Their intellectual offspring, general relativity and quantum mechanics, have long [*] been combined into a unified framework, the Sarumpaet rules, named after the long-dead physicist most associated with them. Much as with other Egan novels, humanity has spread among the stars and exists in a number of physical forms at this point. Natural humans, others who live in synthetic organic or mechanical bodies, and those who have forsaken embodied life and exist in computing infrastructure as so-called Qusps. The novel begins with the arrival of Cass at the Mimosa facility 600 light years from Earth. Cass is a physicist interested in quantum graph theory and with new ideas about how the Sarumpaet rules can be tested much more strenuously than ever before. The Mimosa facility affords a quantum mechanical "quietness" that can best allow these tests, and after pleading her case with its administrators, Cass is permitted to begin her experiments. However, despite all of the precautions that Cass and the Mimosans take, the final test goes "wrong" and a startling transformation of the universe's underlying spacetime occurs, creating a fast-expanding "novo-vacuum" with radically different physical properties. Her consciousness copied to a Qusp to watch the experiment at ultra-high speed, Cass and her colleagues watch, horrified, as this novo-vacuum expands to destroy the Mimosa facility.

The novel then jumps forward several hundred years. The novo-vacuum has continued to expand at half the speed of light and by now has consumed a number of inhabited systems. While casualties have been extremely light because of the predictability of the expansion, a Preservationist faction has arisen to contain or even destroy the novo-vacuum. But a Yielder faction balances them, composed of those who believe that adaptation to the novo-vacuum may be possible and that this new state of affairs has shaken up a torpid and stale society. Tchicaya is one of the Yielders who has joined a joint mission with the Prevervationists that has positioned a ship, the Rindler, just beyond the moving envelope of the novo-vacuum. From there the mission observes and performs experiments on the blossoming physical realm expanding just behind their ship. Tchicaya is unsettled by the arrival of his first, but unconsummated, love, Mariama, now one of the Preservationists. He is haunted by the event that divided them centuries before, their discovery of primitive, native life on a colonised world, a finding that led to the quarantine and evacuation of the planet. Humanity has found life to be exceedingly rare, and none of what has been found has approached sentience, so for Tchicaya the novo-vacuum offers the possibility of a new realm to search for it. However, even the nature of the "space" that lies behind the novo-vacuum's border is uncertain, prolonging the incomprehension of the human factions, and allowing the divisions between them to grow.

But a breakthrough in understanding opens the door both to exploration of the novo-vacuum and to the invention of weapons, the planck worms, that may assist in its destruction. Further exploration reveals a physics in the "far side" much richer than that in the "near side", one in which the ostensible vacuum itself writhes with apparent life. What's more, deeper probes into the far side discern unexpected structure and trigger apparent signals from organisms living there, dubbed the vendeks because of their size. At the same time, a sub-faction of Preservationists makes a desperate bid to wrest control of the Rindler, and initiates the release of the planck worms. Faced with the potential loss of the first sentient life that humanity has long been searching for, Tchicaya and Mariama abandon corporeal form and transmit themselves to the far side.

As the (over)long outline above implies, this is a novel with a well thought-out plot, and one which I generally really enjoyed. But it comes with a huge caveat. As I noted right at the start, this is hard science fiction with a capital HARD, and while Egan has created an exciting and imaginative future, he's also carefully thought through the physics that underlies the story. And, unfortunately (for this reader at least), not just thought about it, he's actually jammed it wholesale into the book.

Now, Egan hasn't gone so far to include any equations (though he does include one or two diagrams), but his language is extremely physics-heavy, and long sections of the prose delve, unremittingly, into the extrapolated physics that he's invented for the novel. He's good enough a writer for it to avoid being clunky, in fact it sounds convincingly like mathematical conversations I've eavesdropped over the years, but it's still the sort of thing that's only ever going to be understood fully by that small minority of readers with a strong interest in theoretical physics. I understood practically none of Egan's description, and had to take almost all of it with a pinch of salt, much as I occasionally do at work when some aspect of physical oceanography is being explained.

The upshot of all this is that the novel is something of a compromised read. On the one hand, it's hardly satisfying to have to essentially skim read long sections of the novel (especially given the effort that's clearly gone into them), but on the other hand, Egan has created a very imaginative and enjoyable (when away from the physics) far-future romp. I particularly took to the theme of looking for alien life, the significance this had to Egan's characters, and the lengths to which they'd go to protect it. I also really liked the idea that our world, far from being the pinnacle of creation, is actually an impoverished backwater, a near-lifeless ocean of empty space, while the novo-vacuum (sic) is teeming over with life. But then, I'm always a sucker for anthropic pedestal-knocking.

Anyhow, leaving aside the physics, the novel works pretty successfully. The plot rolls steadily along, with a lot of nice detail blended in, and with a nice progression to the climactic exploration of the far side. As with much science fiction, the characters definitely take something of a backseat, at times to the point where I struggled to work out which of the secondary characters was speaking, and for what faction. But by having only a few main characters, even ones who were not quite fully three-dimensional, I never drifted too far. But it would still be a little difficult to recommend to anyone other than a fan of the hard. Egan's zeal to show the workings behind his fictional world is admirable in a way, but here it really interferes with his storytelling. Other authors like Iain M. Banks occasionally introduce transcendent physics (or the appearance of it), but they do so more through lyrical or qualitative prose than the laying out of carefully-crafted mathematical edifices (which, in the case of Banks at least, is in no small part down to him having a BA rather than a BSc).

In passing, this trait of comprehensively nailing the physics is not a new one for Egan. The novels of his that I read pre-blog, Permutation City and Diaspora, also lay the physics on rather thickly. The former deals with the transfer of minds to something like the Qusps here, and also, curiously enough, with the evolution of alien life created by human actions. Meanwhile, the latter significantly broadens its scope, beginning with the development of a Qusp from its (or vis, to use the novel's pronouns) virtual birth, and ending with a search for extraterrestrial intelligence that ultimately jumps from universe to universe through a vividly created multiverse. Interestingly, Egan's short fiction, by virtue of its length, generally steers him away from long expositions of physics, so plays to his strengths as a master of ideas.

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[*] Though the novel is set around 20,000 years in the future, Egan kindly drops the unification of GR and QM back at the "turn of the third millennium". Which, given the enormous (but still small) jump forwards in time, probably comes as some relief to theoretical physicists. He could have dropped it at the "turn of the fifteenth millennium", which would have still been ancient history for most of the novel's characters, but that would have made for a rather withering assessment of progress in contemporary physics.

No such thing as free will?

In this week's Nature there's an article entitled "Is free will an illusion?" by a German biologist, Martin Heisenberg. The article makes the oft-repeated assertion that stochastic noise from quantum mechanical processes may be the key to free will in animals such as ourselves. Since it's transparently obvious to me that randomness is no better than pure determinism when it comes to explaining free will (assuming such a thing exists), I fired off a response to Nature. While my suggestion is entirely mechanism-free (I've got nothing on this front), I do think that the appearance our personal reality presents to us is at least suspicious, and hints at some degree of freedom in our actions. I don't entirely buy this myself, principally because I really can't think of anything approaching a plausible mechanism, but I have thought about this on and off for a long time without committing my thoughts to paper or blog. Anyway, seeing as they're so capricious, it's always worth a dabble with Nature, but since the odds of publication are vanishing I thought I may as well reproduce what I submitted here ...

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Martin Heisenberg (Nature 459, 164-165)¹ makes a number of intriguing points concerning the reality (or illusion) of free will in humans and other animals. However, to my mind (free or otherwise), his review overplays randomness as a route out of slavish determinism. Stochastic noise, quantum mechanical or otherwise, hardly seems the path to a triumphant restoration of self-determination. Instead, while it counts more as a hint or indication rather than hard empirical evidence of an underlying mechanism, the appearance of free will is telling from an evolutionary perspective. Assuming that free will is annulled (and I include Heisenberg’s stochasticism in this class), a biologist might well question why natural selection has gone to the bother of giving organisms the perception that they are ploughing their own furrow. If there is no possibility of any consequences of this perception feeding back to guide events, why has selection acted at all? Furthermore, why has selection furnished the minds of animals like ourselves with all sorts of carrots (pleasure and love) and sticks (fear and pain) to guide us towards goals that service the genes that build us? Heisenberg is right to question overeager neurodeterminists, but he may have chosen (or not, of course) the wrong route for doing so. One question for those who deny a seemingly obvious feature of personal reality is why, given that we are only scratching the surface of neurobiology, that we have yet to determine which flavour of quantum reality is the right one, and that the universe contains as-yet inexplicable entities such as dark matter and dark energy, why we can so quickly preclude free will.

¹ Heisenberg, M. (2009). Is free will an illusion? Nature 459, 164-165.

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Before I fired this off, I circulated it to a few of my friends at NOCS. While they generally liked it (or perhaps were just very polite), none of them bought it. What's more, it turns out that two of them, APM and BS, physicists to a man, very much subscribe to the "free will as illusion" school of thought. Not entirely to my surprise since there appears to be nothing by way of a mechanism (let alone a plausible mechanism) for material to somehow be both self-aware and capable of channelling this to affect reality. On this I'd completely agree with them, but I do still have a problem swallowing the idea that we're not free (to a degree) on, well, wishful-thinking grounds. Regardless of the subjective fact that I feel free (cf. my articulations in the submitted correspondence), I just don't like the idea that I might not be, and that I am living in a world where it's not possible. APM and BS seem OK with this, but it's not for me. Partly because agreeing with the idea seems somewhat tautological: what, simply, does it mean for me to agree with the proposition that I have no free will, when agreement itself seems to undercut the very notion?

Many Worlds

Caught an interesting science programme on BBC4 the other night. It dealt with the infamous Many Worlds interpretation of quantum mechanics, but from the perspective of the musician Mark Everett (or E), son of the scientist who developed it, Hugh Everett. While I knew of both of these people separately, I was completely unaware that they were related, let alone father and son.

The programme followed Mark as he travelled the US meeting up with Everett's colleagues and with scientists currently working with Many Worlds. The programme devoted some time to the theory itself, but focused more on Everett's life and academic career, and with Mark's relationship with his father. While it probably overstated the importance of Many Worlds, and may give some viewers the idea that this interpretation is the most commonly accepted one among physicists, it was really quite charming.

Mark, who hitherto understood very little about his father's work, gradually came to some understanding of it, and was able to make sense of father's life and certain key events in it. He also came to realise the importance of his father's work, and the modern relevance of the Many Worlds interpretation. A particularly choice moment was when he dug out some old audio tapes from his father's stuff (Everett died in 1982). These recorded conversations with friends and scientific colleagues about his ideas. However, in the course of playing through them, Mark found a recording of their pet cat purring, a boastful recording of himself and, best of all, a conversation his father was having that, in the background, had Mark learning to play the drums.

My own view on Many Worlds is that, while I don't subscribe to it, I find its solution of the "measurement problem" strongly preferable to that of the "standard" Copenhagen interpretation. I simply refuse to buy the idea that measurement is an important factor in the lives of subatomic particles. At first glance, this seems a reasonable deduction given that quantum objects appear to switch from waves to particles when measurements are made of them. The large number of possibilities inherent in waves is instantly decreased to a single actuality by the act of measurement. But it's unclear (to me anyway) what "looking at" a quantum object does to it to make this happen. Many Worlds resolves this by stating that all of these possibilities actually occur, but do so in their own separate universes, such that we only see one outcome (i.e. we, too, are split across multiple universes). While this does elegantly sidestep the measurement problem, it does so at the great expense of an ever-expanding number of universes. I'm not prepared to make that leap. My own view is more along the lines of the neo-realist Bohm interpretation. In my understanding of it, this posits that quantum objects have hidden variables associated with them, such that they are composed of both wave and particle components. These hidden variables explain the dual behaviour of the objects but measurement is not a special process. Of course, this interpretation fails Occam's Razor by profligately introducing unobserved (possibly unobservable) hidden variables. Still, it allows me to continue believing in an external world that carries on regardless of our actions.