pleasant. I laughed numbly. “So this is going to be your ideal working holiday?”
Lee was puzzled. “And yours, too, surely? You must have been hoping desperately for something more than a few sleepy seminars to film. Now you’ll have Violet Mosala versus Janet Walsh. Physics versus the Ignorance Cults. Maybe even riots in the streets: anarchy comes to Stateless, at last. What more could you possibly ask for?”
Denied access to Australian, Indonesian and Papua-New-Guinean airspace, the (Portuguese-registered) plane headed southwest across the Indian Ocean. The waters looked wind-swept, gray-blue and threatening, though the sky above was clear. We’d curve right around the continent of Australia, and we wouldn’t sight land again until we arrived.
I was seated beside two middle-aged Polynesian men in business suits, who conversed loudly and incessantly in French. Mercifully, their dialect was so unfamiliar to me that I could almost tune them out; there was nothing on the plane’s headset worth listening to, and without a signal the device made a poor substitute for earplugs.
Sisyphus could reach the net via IR and the plane’s satellite link, and I considered downloading the reports I’d missed about the cult presence on Stateless—but I’d be there soon enough; anticipation seemed masochistic. I forced my attention back to the subject of All-Topology Models.
The concept of ATMs was simple enough to state: the universe was considered to possess, at the deepest level, a mixture of every single mathematically possible topology.
Even in the oldest quantum theories of gravity, the “vacuum” of empty space-time had been viewed as a seething mass of virtual worm-holes, and other more exotic topological distortions, popping in and out of existence. The smooth appearance at macroscopic lengths and human timescales was just the visible average of a hidden riot of complexity. In a way, it was like ordinary matter: a sheet of flexible plastic betrayed nothing to the naked eye of its microstructure—molecules, atoms, electrons, and quarks—but knowledge of those constituents allowed the bulk substance’s physical properties to be computed: its modulus of elasticity, for example. Space-time wasn’t made of atoms, but its properties could be understood by viewing it as being “built” from a hierarchy of ever more convoluted deviations from its apparent state of continuity and mild curvature. Quantum gravity had explained why observable space-time, underpinned by an infinite number of invisible knots and detours, behaved as it did in the presence of mass (or energy): curving in exactly the fashion required to produce the gravitational force.
ATM theorists were striving to generalize this result: to explain the (relatively) smooth ten-dimensional “total space” of the Standard Unified Field Theory—whose properties accounted for
Nine spatial dimensions (six rolled up tight), and one time, was only what total space appeared to be if it wasn’t examined too closely. Whenever two subatomic particles interacted, there was always a chance that the total space they occupied would behave, instead, like part of a twelve-dimensional hypersphere, or a thirteen- dimensional doughnut, or a fourteen-dimensional figure eight, or just about anything else. In fact—just as a single photon could travel along two different paths at once—any number of these possibilities could take effect simultaneously, and “interfere with each other” to produce the final outcome. Nine space, one time, was nothing but an average.
There were two main questions still in dispute among ATM theorists:
What, exactly, was meant by “all” topologies? Just how bizarre could the possibilities contributing to the average total space become? Did they have to be, merely, those which could be formed with a twisted, knotted sheet of higher-dimensional plastic—or could they include states more like a (possibly infinite) handful of scattered grains of sand— where notions like “number of dimensions” and “space-time curvature” ceased to exist altogether?
And: how, exactly, should the average effect of all these different structures be computed? How should the sum over the infinite number of possibilities be
On one level, the obvious response to both questions was: “Use whatever gives the right answers'—but choices which did that were hard to find… and some of them smacked of contrivance. Infinite sums were notorious for being either intractable, or too pliable by far. I jotted down an example—remote from the actual tensor equations of ATMs, but good enough to illustrate the point:
Let S = 1-1+1-1+1-1+1- …
Then S = (1-1) + (1-1) + (1-1) + … = 0 + 0 + 0 … = 0
But S = 1 + (-1+1) + (-1+1) + (-1+1) … = 1 + 0 + 0 + 0 … = 1
It was a mathematically naive “paradox'; the correct answer was, simply, that this particular infinite sequence didn’t add up to any definite sum at all. Mathematicians would always be perfectly happy with such a verdict, and would know all the rules for avoiding the pitfalls—and software could assess even the most difficult cases. When a physicist’s hard-won theory starred generating similarly ambiguous equations, though, and the choice came down to strict mathematical rigor and a theory with no predictive power at all… or, a bit of pragmatic side-stepping of the rules, and a theory which churned out beautiful results in perfect agreement with every experiment… it was no surprise that people were tempted. After all, most of what Newton had done to calculate planetary orbits had left contemporary mathematicians apoplectic with rage.
Violet Mosala’s approach was controversial for a very different reason. She’d been awarded the Nobel prize for rigorously proving a dozen key theorems in general topology—theorems which had rapidly come to comprise a standard mathematical toolbox for ATM physicists, obliterating stumbling blocks and resolving ambiguities. She’d done more than anyone else to provide the field with solid foundations, and the means of making careful, measured progress. Even her fiercest critics agreed that her
The trouble was, she told her equations too much about the world.
The ultimate test of a TOE was to answer questions like: “What is the probability of a ten-gigaelectronvolt neutrino fired at a stationary proton scattering off a down quark and emerging at a certain angle?'… or even just: “What is the mass of an electron?” Essentially, Mosala prefixed all such questions with the condition: “Given that
Her supporters said she was merely setting everything in context. No experiment happened in isolation; quantum mechanics had been hammering that point home for the last hundred and twenty years. Asking a Theory of Everything to predict the chance of observing some microscopic event—without adding the proviso that “there is a universe, and it contains, among other things, equipment for detecting the event in question'—would be as nonsensical as asking: “If you pick a marble out of a bag, what are the odds that it will be green?”
Her critics said she used circular reasoning, assuming from the very beginning all the results she was trying to prove. The details she fed into her computations included so
I was hardly qualified to come down on either side… but it seemed to me that Mosala’s opponents were being hypocritical, because they were pulling the same trick under a different guise: the alternatives
But some local fluctuation had disturbed the balance in such a way as to give rise to the Big Bang. From that tiny accident, our universe had burst into existence. Once that had happened, the original “infinitely hot,” infinitely even-handed mixture of topologies had been forced to become ever more biased, because “temperature” and “energy” now had a meaning—and in an expanding, cooling universe, most of the “hot” old symmetries would have been as unstable as molten metal thrown into a lake. And when they’d cooled, the shapes into which they’d frozen