Markham shook himself out of the mood, feeling an odd chill run through him. There was something deeper here, some crucial missing physics.
He walked rapidly away, disturbed. A cricket game lazily wound through the afternoon on the large pie-shaped ground known as Parker’s Piece. The mathematician G. H. Hardy had watched games there a century before, Markham mused, and often lazed away the afternoon just as he was doing now. Markham could understand the motivation of the game, but not the details. He had never got straight the cricket jargon—square leg, silly mid-on, silly mid-off, cover point, short extra cover—and still never quite knew when a good play was made. He walked behind the ranks of spectators, who were slumped in their canvas chairs, and wondered what the cricket watchers of a century ago would’ve thought of the England of now. He suspected, though, that like most people even today, they assumed that tomorrow would be pretty much the same as the present.
Markham angled down Regent Street and past the University Botanic Garden. Beyond lay a boys’ school. Dispensing the norms and graces of the upper classes, in a king’s ancient phrase. He strolled through the arched entranceway and paused at the school announcements board. The following have lost their personal possessions. They will call at the Prefect’s Study by Thursday 4th June.
No “please.” No unnecessary softenings; simply a direct statement. Markham could imagine the brief conversation: “I’m sorry, you see—” “Standard punishment. Fifty lines, best handwriting. I’ll have them tomorrow at break.” And the student would grind out, My carelessness with my personal property will cease.
The fact that the student might well use one of the recent voice-writers for nearly all his school work didn’t matter; the principle reigned.
Odd, how forms held on when everything else—buildings, politics, fame—fell away Maybe that was the strength of this place. There was a timelessness here, too fragile for California’s dry air to hold. Now that full summer had arrived with a flourish, the mannered ways of the schools and colleges seemed even older, a slice of worn time. He found his own spirits lifting at the release from the endless raw winter and the rainy spring.
He felt his mind veering away from the tachyon question, seeking refuge in this comfortable aura of the past. It was different for him here, he knew. Englishmen were fish swimming in this sea of the past. For them it was a palpable presence, a living extension, commenting on events like a half-heard stage whisper. Americans regarded the past as a parenthesis within the running sentences of the present, an aside, something out of the flow.
He walked back towards the colleges, letting this feel of the press of time seep into him. He and Jan had been to High Table at several of the colleges, the ultimate Anglophile experience. Memorial plate that gleamed like quicksilver, and crested goblets. In the after-dinner room of polished wood, gilt frames held glowering portraits of the college founders. In the great dining hall Jan had been surprised to find de facto segregation: Etonians at one table, Harrovians at another, the lesser public schools’ alumni at a third, and, finally, state school graduates and everyone else at a motley last table. To an American in such a citadel of education, after the decades of ferocious equality-at-all-costs politics, it seemed strange. There persisted a reliance on inherited advantages, and even the idea that such a system was an inherited virtue as well. The past hung on. You could be quite up to the minute, quite knowing about the zack-o latin riffs of Lady Delicious, and yet sit quietly and comfortably in choir stalls of King’s College chapel listening to cherubic lads in Elizabethan ruffs try to shatter the stained glass with treble attacks. It seemed that in a muzzy sense the past was still here, that they were all connected, and that the perception of the future as a tangible thing lived in the present, as well.
Markham relaxed a moment, letting the idea inside drift up from his subconscious. Walking was the gentle jog his mind needed; he had used the effect before. Something… something about the reality needing to be independent of the observer…
He glanced up. A swarming yellow cloud, moving fast and low over the gray towers, pressed shadows against the flanks of Great St. Mary’s church. Bells pealed a cascade of sound through momentarily chilled air; the cloud seemed to suck heat from the breeze.
He watched the curling fingers of fog that dissolved overhead in the trail of the cloud. Then, abruptly, he had it. The nub of the problem was that observer, the guy who had to see things objectively. Who was he? In quantum mechanics, the equations themselves told you nothing about which way time should run. Once you made a measurement, an experiment had to be thought of from that moment on as a thing which generated probabilities. All the equations could tell you was how probable a “later” event was. That was the essence of the quantum. Schrödinger’s equation could evolve things either forward in time, or backward. Only when the observer poked his finger in and made a measurement did something fix the direction of the flow of time. If the all-powerful observer measured a particle and found it at position x, then the particle had to be given a small push by the observer, in the very act of observing. That was Heisenberg’s uncertainty principle. You could not tell precisely how much of a push the observer had given the wretched particle, so its future position was somewhat uncertain. Schrödinger’s equation described the set of probabilities about where the particle would appear next. The probabilities were found by picturing a wave, moving forward in time and making it possible for the particle to appear in many different places in the future. A probability wave. The old billiard-ball picture, in which the particle moved with Newtonian certainty to its next point, was simply false, misleading. The particle’s most probable location was, in fact, exactly the same as the Newtonian position—but other paths were possible. Less likely, yes, but possible. The problem came when the observer next poked his finger in and made a second measurement. He found the particle in one place, not spread out among a choice of spots. Why? Because the observer was always considered essentially Newtonian himself—a “classical measurer,” as the tech chat went.
Markham grinned broadly as he turned up King’s Parade. There was a trapdoor in that argument. The classical observer didn’t exist. Everything in the world was quantum-mechanical. Everything moved according to waves of probability. So the massive, untouched experimenter himself got pushed back on. He received an uncertainly known push from the outraged particle, and that meant the observer, too, was quantum-mechanical. He was part of the system. The experiment was bigger, and more complex, than the simple ideas of the past. Everything was part of the experiment; nobody could stand apart from it. You could talk about a second observer, bigger than the first one, who was unaffected by the experiment—but that simply removed the problem one step further. The final fallback was to regard the whole universe as the “observer,” so that it was a self-consistent system. But that meant you had to solve the entire problem of the motion of the universe at once, without breaking it up into convenient, separate experiments.
The essence of the problem was, what made the particle appear in only one spot? Why did it pick out one of the possible states and not another? It was as though the universe had many possible ways it could go, and something made it choose a particular one.