But there was one exception. The kosho still kept to the rear of the party. Looking back, Hesper noticed that his forehead remained unmarked. She fancied she saw a hint of a smile on his face as he received her attention, as though to convey to her some private joke.
Then they were in Mo. The path gave onto a broad esplanade paved with hexagonal slabs a pale gold in colour. At its fringe people sat at tables under awnings before arcaded doorways, talking and drinking, attended by flimsy-looking robots. At intervals, avenues led to other places.
Hesper lifted her eyes. Up, up and up rose the moulded towers, connected by bridges, interspersed with terraces, suspended plazas and esplanades, all shining in the evening sun. They stood on the ground floor of the city, so to speak, but it had many floors, at dizzying levels.
It was, she had to admit, the most entrancing urban construct she had even seen.
And to think that all this moved.
She pulled on her clothing again, no longer feeling overheated. She reminded herself that she was here for a purpose: to try to join up with whatever remnants of rebel forces their might be, or failing that, to get home.
Pout was staring about himself with a look of idiocy. He seemed to be in shock: culture shock, perhaps.
She patted him on the head. “Well thanks for the company, ape. So long.”
With that, she skipped off lightly to join the Mohists.
Later, she lay back with a sigh on the divan in the delightful accommodation she had been given.
Her conversations with the Mohists had not proved helpful. They seemed disinterested in the outside world beyond the plain. For news of or travel to other planets, she would have to go to some other part of Earth, they had told her. And how did she do that?
She would have to walk. Mo offered no transport facilities, beyond its own enormous treads whose rumblings could, occasionally, be heard in quieter moments.
They had smiled in dazed fashion when she questioned them on the coming end of the world. Earth, they claimed, was about to collide with its own moon. Nothing could prevent it. Mo himself had confirmed the likelihood of it happening.
Recalling what Sinbiane had said, she felt perplexed, almost frightened. Then one of the robots, who seemed to take care of everything, had approached and offered to take her to her apartment. There she had showered, removing the dirt and sweat of the last few days. Now she rested.
The pending satellite collision could not be taken seriously. The universe could be a violent place, but sudden events did not happen without lengthy warning. If this planet’s moon had an orbit so unstable as to decay into its primary, the fact would have been known the Simplex knew how long ago. It would have been the talk of Escoria.
Her own private explanation was that she was being told a cultural fable. The satellite probably had an orbit with variable eccentricity which made it approach closer to the planet at long intervals. That would explain why the boy hadn’t seen it grow visibly bigger before.
As for the Mohists, they were probably crazies, no longer able to separate fable from reality. Centuries of enclosed life, no matter how pleasant the surroundings, under the tutelage of a city-mind that was virtually a god as far as they were concerned, could hardly produce anything else.
A tone suddenly sounded, the same she had heard at the gate. The voice that followed, however, was masculine.
“Visitor, this is Mo speaking. It is time for your evening lecture.”
Hesper started, thrilled despite herself. The voice was that of a young but mature man, vigorous and confident. It brought to mind the sort of visage she had seen on ancient statues, framed in dark curls, handsome, intelligent and strong. The face of a deity…
A thought struck her. Could it be that some of the city minds had female gender?
There could be more ramifications to this society than she had penetrated so far.
Almost coyly, she said. “I’m tired, I’ll skip the lecture, thank you.”
“Education is obligatory,” the godlike voice replied gently. “The whole point of a leisured class is that it may cultivate the mind. Your weariness is in body only. Since you are too tired to walk to the lecture hall, I shall bring it to you by sensurround. Just relax.”
The room darkened. Hesper seemed to be transported to some other place: a semidark hall, quite small in size though she became aware of its slightly echoing acoustics. It had a plush smell, quite different from her perfumed apartment.
In reality she was also aware that she still lay on her bed; sensory beams were being aimed at her. Down the slope of the lecture room, the display area suddenly lit up with the words:
DISCOVERING THE SIMPLEX
The words cleared: there began a sequence of images accompanying a spoken text, which to Hesper’s mild surprise was voiced by Mo himself.
“The foundation of modern physics,” the voice said in cordial, instructing tones, “was established by Vargo Gridban two thousand years ago. He it was who replaced the picture of space and matter then prevailing, involving several types of fundamental particle with several kinds of forces acting between them, with a scheme requiring only one type of elementary particle and one fundamental force.
“Gridban’s work began with the observation that the spacetime in which we live is so constituted that, while it could accommodate forces of repulsion, forces of attraction ought to be impossible in it. Yet attractive forces—gravitation, electromagnetism, nuclear binding force—do appear to exist and are responsible for both the small and large scale structures in our universe, from atoms to galaxies. Instead of simply accepting the existence of these forces, as scientists before him had done, Gridban came to the opposite conclusion and accepted their impossibility. It followed that gravitation, electromagnetic attraction, and nuclear force could only be apparently attractive: they might even depend on a completely opposite type of phenomenon for their effect.
“Gridban’s own special contribution was in the field of gravitation. The supremely subtle set of experiments he proposed established two things. First, that gravitating bodies fail to obey the Newtonian law of action and reaction. That they superficially appear to obey it is due to the acceleration of a gravitating body being independent of its mass. In fact the motion of a satellite, to take in example, is due solely to the presence of its primary. It does not contribute to that motion by reacting to its own influence upon the primary.
“Second, Gridban was able to demonstrate that there is actually no connecting casual link at all between gravitating bodies. That is the reason for the failure of Newton’s third law: gravitating bodies are not, in fact, acting on one another. Eventually Gridban was able to prove that gravitation is a residual phenomenon, not a positive force. The road was opened to our present knowledge of space and its relation to matter.
“Space is kinetic, not static in character. It consists purely of relationships between material particles, and fundamentally there is only one relationship: every particle in existence attempts to recede from every other particle at the velocity of light. The recessive factor between any two particles is known as a recession line. The structure we call ‘space’ consists of a mesh of recession lines. Between lines, in the interstices not on any route between particles, no ‘space’ or anything else exists.
“Actually the spacetime we live in is of a rather special kind. You are probably already acquainted with the following geometrical facts: on a one-dimensional line no more than two points can be selected so as to be equidistant from one another; on a two-dimensional plane, as many as three points may be equidistant, forming the apices of an equilateral triangle; in our real space of three dimensions as many as four points may be equidistant, forming the apices of a tetrahedron; in a four-dimensional continuum a fifth point could be added to form a pentope; and so on. For each extra dimension one more point can be added. Such a configuration of equidistant points is known as a simplex, and each simplex exemplifies a particular dimensional set.