On

by Adam Roberts

  He returned to collect Mulvaine and share some of this new bread. He had left him on the central shelf watching the never-ending play. ‘Let’s go now, Mulvaine,’ he said.

  ‘In a moment, Master,’ said Mulvaine. Tighe had given up rebuking him for calling him ‘Master’; there seemed little point. ‘This actor is staggering and about to fall, I think.’

  Tighe pushed through to get a better view. Mulvaine, as a slave, had not dared do so; but he was tall enough to see over the crowd. Tighe squeezed through and saw the actor enter into a lengthy monologue. He was dressed in bright red fabric, but he was plainly exhausted: his face was yellow with fatigue, and his hands trembled like vibrating machines of some kind. He croaked his lines rather than spoke them. Two young actors, eager and fidgety, waited on the outskirts of the stage space, to race one another and claim the role of the failing actor.

  He pulled himself up, his voice dry and cracked. ‘I am to take on the clothing of death himself,’ he warbled. ‘I am to take on the clothing of ending itself. He span round in a slow, ritualised arc and ended with his arm outstretched. The tremor of his hand was painful to see. He was pointing at one of his fellow actors. ‘I am to clothe myself as death,’ he said again. ‘I am to clothe myself as ending. I am to clothe myself as death. I am to clothe myself as ending.’

  ‘The world is tall,’ said the other actor. This had been her only line for the last half-hour. Tighe knew this because somebody in the crowd next to him said so, loudly and crossly. ‘Over and over!’ this audience member said.

  ‘Hish!’ said somebody else.

  ‘The world is tall,’ said the other actor. She was dressed in green cloth.

  ‘As the sun rises,’ said the first actor, breathlessly. He pointed at the shelf. ‘As it rises and goes over the wall.’ He pointed upwards. But this gesture was the final straw. His leg wobbled comically and then he simply fell straight down in a heap. The other two actors were hurrying on, fighting amongst themselves to take the position centre-stage and kicking the prone figure of the previous actor in their eagerness to clear him away.

  ‘As the sun rises,’ shouted the first actor.

  ‘As it rises and goes over the wall,’ yelled the other, and raised his arm, bringing it sharply down in a blow to the other’s face.

  Tighe turned away, and pushed his way out of the crowd again. ‘Come along now, Mulvaine,’ he said. ‘You’ve seen the old actor pass out.’

  ‘Master,’ whined Mulvaine, bobbing his head to get the best view. ‘Can’t we stay half an hour more! It’s the sunrise speech! It’s a famous speech.’

  ‘No,’ snapped Tighe, his temper fraying. ‘We must go now.’

  Mulvaine hobbled along behind him in a sullen mood, but Tighe felt lighthearted to be leaving the city. Sharp needle pains came and went in his eyes and he had developed the suspicious feeling that these new headaches were somehow brought on by his being in the city itself. ‘They’ll go when I leave the city,’ he told himself.

  They climbed to a higher ledge that led west.

  ‘Stop!’ called somebody, from behind. Tighe and Mulvaine turned together. One of the old men from the same space as Mulvaine’s old master was standing there, his walking stick horizontal, pointing straight at Tighe.

  The old man had hired a young ruffian to reclaim Mulvaine. This thug was tall and his arms were fat with muscle. As he stepped along the ledge, the old man called after him. ‘Take his jewels too!’ he quavered. ‘He’s got jewels.’

  The thug confronted Tighe. Tighe pulled out his gun. The thug looked at it.

  ‘Is that real?’ he asked, in a surprisingly mellow voice.

  ‘Yes,’ said Tighe and aimed a shot at the ledge. The gun struggled and fired, and a gout of dust flew up.

  The thug took a step back and then turned and marched straight past the old man.

  By evening Tighe and Mulvaine were out of the city and moving west. Most of the traffic on the ledge was going in the other direction, drawn into the city.

  ‘Where are we going?’ asked Mulvaine, as the two of them settled into a nook in the wall to sit out the dusk gale.

  ‘We’re going to my village, Mulvaine,’ said Tighe. ‘Going home.’

  Mulvaine didn’t say anything. After a while he said, ‘My skin has been rubbed raw by walking so far, Master. My skin under my arm.’ He said this in a pitiful, small voice.

  ‘You’ll get used to it,’ said Tighe. ‘The dusk gale is so mild this far east,’ he added. ‘Do you remember how harsh the dusk gale used to be, back in the Empire?’

  But Mulvaine was not to be drawn by nostalgia.

  The next morning Mulvaine shared out rations from his pack and the two of them started marching west. The air was clear and the strong rays of the sun from below illuminated the wall before them with streaks of beauty. The sunlight was hurting Tighe’s eyes, but he tried not to think about that. Soon enough his eyes would get better; his eyesight would become less misty and the pain would stop. Soon enough they would pass through the Meshwood and find their way up to his village.

  The path led out along a stubby spur of worldwall. At its furthest point Tighe looked back. The distant outline and haze of the city was still visible, just. Tighe breathed deeply and waved languidly. Mulvaine waited, poised on his crutch, looking at the floor and panting. For a moment Tighe pondered his time in the city; but the sense of freedom was so exquisite it made his hair prickle and stand on end. Freedom, and the path home.

  After this short pause, he and Mulvaine walked on. Rounding the spur and starting down the far side.

  The Wizard was there, waiting, as if he had been waiting all this time. His eyes were red lamps. He was wearing a black plastic cloak that flapped and curled around his leather skin.

  ‘Tighe,’ he said in his squeaky voice, but with an edge of malice. ‘My Lover has been at you, tampered with my machines, and I’ve found it hard to track you. Hard! And I’ve had my own worries, my own battles to fight.’

  ‘Wizard!’ said Tighe. The manliness, the swagger and the self-belief – all of it fell away, like sheets and great flakes of ice falling off the end of the world. He was a boy again, a young boy in front of his Grandhe. ‘Wizard!’ Sweat started on his face.

  ‘My sweet young Tighe,’ said the Wizard, a tone of menace in his voice, ‘I’ve been so looking forward to seeing you again.’

  Appendix

  Notes on the World of On:

  The Physics of the Worldwall

  1.1. The Worldwall. Gravity, which operates in the universe as a whole at 90° to a body of mass (such as a planet), has on this particular world been twisted by Hawking’s over-efficient experiments. Instead of operating perpendicular to the flat of ground, gravity is operating parallel to it, in a spherical standing-wave vortex extending from the notional centre-point of the planet to a circular plane less than a kilometre beyond the surface of the globe. This vortex draws energy through superstring elasticity from surrounding space-time and has currently lasted some 430 standard years.

  The dynamics of the change are difficult to theorise clearly. Of the underlying principles of gravity (that it be always additive, always infinite in range, and always attractive) the first two are unaltered by the shift; were gravity, notionally, to shift through more than 90° clearly the last would be violated. Any shift of less than 90° lacks quantum stability. The gyroscopic rotational realignment alters the equations trivially, but it otherwise satisfies physical necessity.

  1.2. Equations. The standard equations for gravitational attraction have usually taken for granted the linear, lagrangian properties of the gravitational effect, such that each particle exerts line-of-sight pull on every other. In fact, equations contain a blind element that eliminates the torque effect of superenergetic quantum foam. Accordingly, for a spherical body of mass M and radius R, containing N molecules each of molecular weight A, the Newtonian gravitational binding effect of energy Eg will be as follows:

  where is the necessary alig
nment of the vector of attraction.

  Theorists from Podkletnov onwards had postulated localised gravitational instabilities, particularly with reference to certain condensate attributes; and these states were always directly related to the linear part of the gravitational lagrangian L. This in turn involves the very small negative intrinsic cosmological constant of space-time. The older definition of ‘critical regions’ as those where δ2(χ) >|Λ|/8hG, applied prior to the uncovering of over-efficient power sources that drew their energy in a more direct way from quantum foam.

  Gravitational theory had, similarly, long known of certain unstable modes of the classic Einstein space-time dynamic, named ‘zero modes’, which have the same probability to occur as the h=0 configuration (flat space) and a higher probability than all other field configurations. (The probability is proportional to exp(iS[g]/hPlanck), and for the zero-modes one has S=0). Thus a gravitational field would always embody a certain instability towards these configurations. What prevents this in the general bulk of space-time is a certain intrinsic cosmological term δLCosm.(2)=+|Λ|/h2, favouring an h=0 configuration.

  The coherent coupling δLCoherent(2)=−Λ2h2 of the gravitational field to any atomic-molecular aggregation, for instance a central node of mass, always amounts to a local positive cosmological term (which is to say, gravity must be an attractive rather than a repulsive force). This cancels the intrinsic stabilising term δLCosm.(2) and leads to a local instability.

  Therefore, while the regular coupling of gravity to incoherent matter produces a response – a gravitational field – approximately proportional to the strength Tcont of the source, the coherent coupling induces an instability of the field.

  Things go as if a potential well for the field were suddenly opened. The field runs away towards those configurations which are now preferred (although whether this is compatible with the cosmic energetic balance remains moot). The runaway stops at some finite strength of the field, where higher order terms in the lagrangian, which usually can be disregarded, come into play. This duration of this condition is difficult to determine because it depends mainly on the non-perturbative dynamics of the field, and very little on the initial conditions.

  1.3. Doomsday Possibilities. There are two opinions as to what will happen; one is that this gravitational disturbance will exhaust itself within (estimates vary) fifty to five hundred years and gravity will revert to normal. The other is that it will distort superstring alignment in a chain-reaction, interrupting and perverting the universal gravitational constant. This ‘doomsday’ scenario sees the situation of the worldwall as cosmically fatal, with the actual weave of space-time disintegrating over a period of some hundred thousand years, the unravelling beginning at this world but spreading logarithmically throughout the galaxy and possibly further. Should this happen, the basis not only of gravitational attraction, but of atomic coherence, could disintegrate, and the universe as a whole reduce to a sort of chaotic sub-particle soup extremely attenuated through the expanse of remaining space. The greatest danger posed by this eventuality is that it would disrupt the balance offerees maintaining the singularities beneath the event horizons of black holes. Arguably, a shift in the vector would release enormous amounts of stored energy from black holes, with devastating effects.

  It is unclear which of these two hypotheses is the more likely.

  The effect of this shift in the coefficient and alignment of gravity has been to angle the vector of living through 90°. Instead of operating, as it were, from the sky to the ground, gravity on this world now operates from the west’ to the ‘east’, turning the entire world on end and replacing what had been an endless flat plain (punctuated with mountains and valleys) into an endless vertical wall (punctuated with ledges and crevices). West is now ‘up’, and East is ‘down’.

  2. Attributes of the Podkletnovian configuration

  2.1. The Pause. At the surface of the world (or worldwall) gravity is running parallel with wall, rather than conventionally at right angles as is normal. As yet, however, gravity is operating ‘normally’ in the rest of the universe – such that, for instance, the world continues to orbit around the sun. There is accordingly a place where the ‘horizontal’ gravity stops, and the usual gravitational laws reassert themselves. This boundary is known to the inhabitants of the worldwall as the Pause. This barrier, although theoretically navigable simply by pushing through it, in effect creates a seal on the atmosphere of the world. This has significantly raised the air density and pressure between the world and the Pause (something of which the inhabitants of the world are, of course, unaware).1

  2.2. Sunrise and Sunset Atmospheric Turbulence. The worldwall as a dynamic system has now achieved a precarious equilibrium. The atmo-sphere is under a constant gravitational pull and will tend to fall. There is, of course, no ‘ground’ to prevent this fall, and in effect the atmosphere rests upon itself. During the day the air is heated by the sun and will tend to rise, or at least to stop falling; and at night it chills and falls more rapidly. This means that at the cross-over points of dawn and dusk cold falling air meets rising warm air – creating dawn and dusk gales. These gales are most pronounced at the central latitudes (or verticalitudes), and least pronounced out near the Poles.

  2.3. Days and Seasons. From the point of view of an inhabitant of the worldwall, the sun now appears to rise from beneath, to ascend through the sky and to disappear ‘over the top of the wall’. Over the years since the catastrophic realignment of gravity, the earth has – as would be expected – picked up rotational momentum. With the globe spinning faster the day now lasts a little under half the previous twenty-four-hour period. Seasons, on the other hand, are longer drawn out than before. Partly this is because the planet’s solar orbit is counterset by the gyroscopic increased rotation, partly the increased air-pressure (see below) stabilises the shifts in temperature occasioned by the elliptical passage of the planet about the sun. The population of the worldwall continues to count time in ‘months’, for now forgotten reasons; but there are twenty months in a year (divided into ten tithes, two months to a tithe). More specific timekeeping varies from region to region. One popular system divides the day into one hundred and eighty ‘degrees’ from sunrise to sunset; another divides the day into ten ‘hours’, each of a hundred ‘minutes’.

  2.4. History. At the time of this catastrophic realignment of the gravitational field the large bulk of the world’s population perished. The world’s water, chiefly contained in oceanic form, was removed from its usual position and fell through the space between the world’s surface and the Pause; evaporation was significantly reduced by the presence of the Pause, and this heavy rain lasted for a considerable time, although eventually the bulk of this body of water ‘froze out’ at the two poles, creating what would on a normal world have been two enormous mountains of ice. The amount of loose matter, chiefly earth and biomass, which was also dislocated by the change in gravity was small compared to the mass of water, but significant in terms of erosion, as well as constituting the main cause of fatalities. Eleven billion people died in this event, the small population of survivors mostly subsisting underground (or ‘inside the body of the wall’) until the outside environment had reached an equilibrium. A significant proportion of the loose matter lodged itself back on the wall, building up on ledges and overhangs, but the bulk of it was frozen in at the poles with the loose water.

  After a hundred years or so, the remaining population of the planet – minuscule in comparison with what had been before – had settled into a habitual lifestyle. There are enough horizontal spaces (ledges, platforms, crevices and the like) to support small groups of people; springs and rain provide a degree of water, and a variety of plants and animals grow on the surfaces available to them. High amounts of oxygen, raised humidity in the central latitudes (or ‘verticalitudes’) and the presence of many springs and water-sources – chiefly subterranean aquifers fed from the pressure of polar water-ice – enable extensive forestation of c
ertain areas.

  3. Flora and Fauna

  3.1. Claw-caterpils and Other Insect Life. The higher air pressure has changed the dynamic of the fauna and flora of the worldwall. In particular it has allowed many insects to grow to much greater size; the main limitation on insect dimensions being the efficiency of spiracles as a method of diffusing oxygen throughout the organism. At higher pressures, this efficiency is viable over greater distances, and insects can become much larger. With the majority of insect predators destroyed in the catastrophe, and with insects more able than many organisms to adapt to the new environment, a great variety of forms of insect life flourished; larger and larger bugs evolving rapidly in the rapidly changing circumstances.

  Various breeds of insect, particularly the variety known to inhabitants as ‘claw-caterpils’, have developed habits of predation upon non-insect fauna, including human beings. These creatures are strongly attracted to the smell of blood and will eat all components of their prey. They have evolved a variety of coagulant saliva. This prevents the blood from draining out of victims and being lost off the face of the world, and enables the insects to maximise their feast. Claw-caterpils prefer densely forested areas and are rarely seen outside meshwood or tanglewood locations.

  1 Tighe, falling from his village ledge, fell more slowly than a sky-diver would in the present world for this reason; although such falls will nevertheless, of course, usually be fatal.

  Acknowledgements

  I would like to thank Simon Spanton, for excellent editorial and other advice; Malcolm Edwards, Oisin Murphy-Lawless, Steve Calcutt, Rachel Cummings, Abraham Kawa, Tony Atkins, Julie Roberts, David Harris, Bob Eaglestone, Roger Levy, Cathy Preece and Sarah Kennedy. For advice on gravitational matters, I’d like to thank the workers at the Gravitational Institute of Staines, particularly Robert Ayamanski and Francesca Frenacapan.