The City And The Stars - Arthur C. Clarke [32]
‘I attempted to do this many years ago,’ said Khedron, as he sat down at the monitor desk, ‘but the controls were locked against me. Perhaps they will obey me now.’
Slowly, and then with mounting confidence as he regained access to long-forgotten skills, Khedron’s fingertips moved over the control desk, resting for a moment at the nodal points in the sensitive grid buried in the panel before him.
‘I think that’s correct,’ he said at last. ‘Anyway we’ll soon see.’
The screen glowed into life, but instead of the picture which Alvin had expected, there appeared a somewhat baffling message:
REGRESSION WILL COMMENCE AS SOON AS YOU HAVE SET RATE CONTROL
‘Foolish of me,’ muttered Khedron. ‘I got everything else right, and forgot the most important thing of all.’ His fingers now moved with a confident assurance over the board, and as the message faded from the screen he swung round in his seat so that he could look at the replica of the city.
‘Watch this, Alvin,’ he said. ‘I think we are both going to learn something new about Diaspar.’
Alvin waited patiently, but nothing happened. The image of the city floated there before his eyes in all its familiar wonder and beauty—though he was conscious of neither now. He was about to ask Khedron what he should look for when a sudden movement caught his attention, and he turned his head quickly to follow it. It had been no more than a half-glimpsed flash or flicker and he was too late to see what had made it. Nothing had altered; Diaspar was just as he had always known it. Then he saw that Khedron was watching him with a sardonic smile, so he looked again at the city. This time, the thing happened before his eyes.
One of the buildings at the edge of the Park suddenly vanished, and was replaced instantly by another of quite different design. The transformation was so abrupt that had Alvin been blinking he would have missed it. He stared in amazement at the subtly altered city, but even during the first shock of astonishment his mind was seeking for the answer. He remembered the words that had appeared on the monitor screen—REGRESSION WILL COMMENCE—and he knew at once what was happening.
“That’s the city as it was thousands of years ago,’ he said to Khedron. ‘We’re going back in time.’
‘A picturesque but hardly accurate way of putting it,’ replied the Jester. ‘What is actually happening is that the monitor is remembering the earlier versions of the city. When any modifications were made, the memory circuits were not simply emptied; the information in them was taken to subsidiary storage units, so that it could be recalled whenever needed. I have set the monitor to regress through those units at the rate of a thousand years a second. Already, we are looking at the Diaspar of half a million years ago. We’ll have to go much further back than that to see any real changes—I’ll increase the rate.’
He turned back to the control board, and even as he did so, not one building but a whole block whipped out of existence and was replaced by a large oval amphitheatre.
‘Ah, the Arena!’ said Khedron. ‘I can remember the fuss when we decided to get rid of that. It was hardly ever used, but a great many people felt sentimental about it.’
The monitor was now recalling its memories at a far higher rate; the image of Diaspar was receding into the past at millions of years a minute, and changes were occurring so rapidly that the eye could not keep up with them. Alvin noticed that the alterations to the city appeared to come in cycles; there would be a long period of statis, then a whole rash of rebuilding would break out, followed by another pause. It was almost as if Diaspar were a living organism, that had to regain its strength after each explosion of growth.
Through all these changes, the basic design of the