Collected Stories Of Arthur C. Clarke (16 page)

The navigator, checking his position continually by the North Atlantic radio lattice, seldom had any need for this part of the liner’s radar. But to the passengers, the big skiatron indicator on the promenade deck was a source of constant interest, especially when the weather was bad and there was nothing to be seen below but the undulating hills and valleys of the cloud ceiling. There was still something magical, even in this age, about a radar landfall. No matter how often one had seen it before, it was fascinating to watch the pattern of the coastline forming on the screen, to pick out the harbours and the shipping and, presently, the hills and rivers and lakes of the land beneath.

To Edward Lindsey, returning from a week’s leave in Europe, the Plan Position Indicator had a double interest. Fifteen years ago, as a young Coastal Command radio observer in the War of Liberation, he had spent long and tiring hours over these same waters, peering into a primitive forerunner of the great five-foot screen before him. He smiled wryly as his mind went back to those days. What would he have thought then, he wondered, if he could have seen himself as he was now, a prosperous accountant, travelling in comfort ten miles above the Atlantic at almost the velocity of sound? He thought also of the rest of S for Sugar’s crew, and wondered what had happened to them in the intervening years.

At the edge of the scan, just crossing the three-hundred-mile range circle, a faint patch of light was beginning to drift into the picture. That was strange: there was no land there, for the Azores were further to the south. Besides, this seemed too ill-defined to be an island. The only thing it could possibly be was a storm-cloud heavy with rain.

Lindsey walked to the nearest window and looked out. The weather was extraordinarily fine. Far below, the waters of the Atlantic were crawling eastward towards Europe; even down to the horizon the sky was blue and cloudless.

He went back to the P.P.I. The echo was certainly a very curious one, approximately oval and as far as he could judge about ten miles long, although it was still too far away for accurate measurement. Lindsey did some rapid mental arithmetic. In twenty-five minutes it should be almost underneath them, for it was neatly bisected by the bright line that represented the aircraft’s heading. Track? Course? Lord, how quickly one forgot that sort of thing! But it didn’t matter – the wind could make little difference at the speed they were travelling. He would come back and have a look at it then, unless the gang in the bar got hold of him again.

Twenty minutes later he was even more puzzled. The tiny blue oval of light gleaming on the dark face of the screen was now only fifty miles away. If it were indeed a cloud, it was the strangest one he had ever seen. But the scale of the picture was still too small for him to make out any details.

The main controls of the indicator were safely locked away beneath the notice which read: PASSENGERS ARE REQUESTED NOT TO PLACE EMPTY GLASSES ON THE SKIATRON. However, one control had been left for the use of all comers. A massive three-position switch – guaranteed unbreakable – enabled anyone to select the tube’s three different ranges: three hundred, fifty, and ten miles. Normally the three-hundred-miles picture was used, but the more restricted fifty-mile scan gave much greater detail and was excellent for sightseeing overland. The ten-mile range was quite useless and no one knew why it was there.

Lindsey turned the switch to 50, and the picture seemed to explode. The mysterious echo, which had been nearing the screen’s centre, now lay at its edge once more, enlarged six-fold. Lindsey waited until the afterglow of the old picture had died away; then he leaned over and carefully examined the new.

The echo almost filled the gap between the forty- and fifty-mile range circles, and now that he could see it clearly its strangeness almost took his breath away. From its centre radiated a curious network of filaments, while at its heart glowed a bright area perhaps two miles in length. It could only be fancy – yet he could have sworn that the central spot was pulsing very slowly.

Almost unable to believe his eyes, Lindsey stared into the screen. He watched in hypnotised fascination until the oval mist was less than forty miles away; then he ran to the nearest telephone and called for one of the ship’s radio officers. While he was waiting, he went again to the observation port and looked out at the ocean beneath. He could see for at least a hundred miles – but there was absolutely nothing there but the blue Atlantic and the open sky.

It was a long walk from the control room to the promenade deck, and when Sub-Lieutenant Armstrong arrived, concealing his annoyance beneath a mask of polite but not obsequious service, the object was less than twenty miles away. Lindsey pointed to the skiatron.

‘Look!’ he said simply.

Sub-Lieutenant Armstrong looked. For a moment there was silence. Then came a curious, half-strangled ejaculation and he jumped back as if he had been stung. He leaned forward again and rubbed at the screen with his sleeve as if trying to remove something that shouldn’t be there. Stopping himself in time, he grinned foolishly at Lindsey. Then he went to the observation window.

‘There’s nothing there. I’ve looked,’ said Lindsey.

After the initial shock, Armstrong moved with commendable speed. He ran back to the skiatron, unlocked the controls with his master key and made a series of swift adjustments. At once the time-base began to whirl round at a greatly increased speed, giving a more continuous picure than before.

It was much clearer now. The bright nucleus
was
pulsating, and faint knots of light were moving slowly outward along the radiating filaments. As he stared, fascinated, Lindsey suddenly remembered a glimpse he had once of an amoeba under the microscope. Apparently the same thought had occurred to the Sub-Lieutenant.

‘It – it looks alive!’ he whispered incredulously.

‘I know,’ said Lindsey. ‘What do you think it is?’

The other hesitated for a while. ‘I remember reading once that Appleton or someone had detected patches of ionisation low down in the atmosphere. That’s the only thing it can be.’

‘But its structure! How do you explain that?’

The other shrugged his shoulders. ‘I can’t,’ he said bluntly.

It was vertically beneath them now, disappearing into the blind area at the centre of the screen. While they were waiting for it to emerge again they had another look at the ocean below. It was uncanny; there was still absolutely nothing to be seen. But the radar could not lie. Something
must
be there –

It was fading fast when it reappeared a minute later, fading as if the full power of the radar transmitter had destroyed its cohesion. For the filaments were breaking up, and even as they watched the ten-mile-long oval began to disintegrate. There was something awe-inspiring about the sight, and for some unfathomable reason Lindsey felt a surge of pity, as though he were witnessing the death of some gigantic beast. He shook his head angrily, but he could not get the thought out of his mind.

*

Twenty miles away, the last traces of ionisation were dispersing to the winds. Soon eye and radar screen alike saw only the unbroken waters of the Atlantic rolling endlessly eastwards as if no power could ever disturb them.

And across the screen of the great indicator, two men stared speechlessly at one another, each afraid to guess what lay in the other’s mind.

The Fires Within

First published in
Fantasy
, August 1947, as by ‘E. G. O’Brien’

Collected in
Reach for Tomorrow

‘This,’ said Karn smugly, ‘will interest you. Just take a look at it!’

He pushed across the file he had been reading, and for the
nth
time I decided to ask for his transfer or, failing that, my own.

‘What’s it about?’ I said wearily.

‘It’s a long report from a Dr Matthews to the Minister of Science.’ He waved it in front of me. ‘Just read it!’

Without much enthusiasm, I began to go through the file. A few minutes later I looked up and admitted grudgingly: ‘Maybe you’re right – this time.’ I didn’t speak again until I’d finished….

My dear Minister (the letter began). As you requested, here is my special report on Professor Hancock’s experiments, which have had such unexpected and extraordinary results. I have not had time to cast it into a more orthodox form, but am sending you the dictation just as it stands.

Since you have many matters engaging your attention, perhaps I should briefly summarise our dealings with Professor Hancock. Until 1955, the Professor held the Kelvin Chair of Electrical Engineering at Brendon University, from which he was granted indefinite leave of absence to carry out his researches. In these he was joined by the late Dr Clayton, sometime Chief Geologist to the Ministry of Fuel and Power. Their joint research was financed by grants from the Paul Fund and the Royal Society.

The Professor hoped to develop sonar as a means of precise geological surveying. Sonar, as you will know, is the acoustic equivalent of radar, and although less familiar is older by some millions of years, since bats use it very effectively to detect insects and obstacles at night. Professor Hancock intended to send high-powered supersonic pulses into the ground and to build up from the returning echoes an image of what lay beneath. The picture would be displayed on a cathode ray tube and the whole system would be exactly analogous to the type of radar used in aircraft to show the ground through cloud.

In 1957 the two scientists had achieved a partial success but had exhausted their funds. Early in 1958 they applied directly to the government for a block grant. Dr Clayton pointed out the immense value of a device which would enable us to take a kind of X-ray photo of the Earth’s crust, and the Minister of Fuel gave it his approval before passing on the application to us. At that time the report of the Bernal Committee had just been published and we were very anxious that deserving cases should be dealt with quickly to avoid further criticisms. I went to see the Professor at once and submitted a favourable report; the first payment of our grant (S/543A/68) was made a few days later. From that time I have been continually in touch with the research and have assisted to some extent with technical advice.

The equipment used in the experiments is complex, but its principles are simple. Very short but extremely powerful pulses of supersonic waves are generated by a special transmitter which revolves continuously in a pool of a heavy organic liquid. The beam produced passes into the ground and ‘scans’ like a radar beam searching for echoes. By a very ingenious time-delay circuit which I will resist the temptation to describe, echoes from any depth can be selected and so pictures of the strata under investigation can be built up on a cathode ray screen in the normal way.

When I first met Professor Hancock his apparatus was rather primitive, but he was able to show me the distribution of rock down to a depth of several hundred feet and we could see quite clearly a part of the Bakerloo Line which passed very near his laboratory. Much of the Professor’s success was due to the great intensity of his supersonic bursts; almost from the beginning he was able to generate peak powers of several hundred kilowatts, nearly all of which was radiated into the ground. It was unsafe to remain near the transmitter, and I noticed that the soil became quite warm around it. I was rather surprised to see large numbers of birds in the vicinity, but soon discovered that they were attracted by the hundreds of dead worms lying on the ground.

At the time of Dr Clayton’s death in 1960, the equipment was working at a power level of over a megawatt and quite good pictures of strata a mile down could be obtained. Dr Clayton had correlated the results with known geographical surveys, and had proved beyond doubt the value of the information obtained.

Dr Clayton’s death in a motor accident was a great tragedy. He had always exerted a stabilising influence on the Professor, who had never been much interested in the practical applications of his work. Soon afterward I noticed a distinct change in the Professor’s outlook, and a few months later he confided his new ambitions to me. I had been trying to persuade him to publish his results (he had already spent over £50,000 and the Public Accounts Committee was being difficult again), but he asked for a little more time. I think I can best explain his attitude by his own words, which I remember very vividly, for they were expressed with peculiar emphasis.

‘Have you ever wondered,’ he said, ‘what the Earth really is like inside? We’ve only scratched the surface with our mines and wells. What lies beneath is as unknown as the other side of the Moon.

‘We know that the Earth is unnaturally dense – far denser than the rocks and soil of its crust would indicate. The core may be solid metal, but until now there’s been no way of telling. Even ten miles down the pressure must be thirty tons or more to the square inch and the temperature several hundred degrees. What it’s like at the centre staggers the imagination: the pressure must be thousands of tons to the square inch. It’s strange to think that in two or three years we may have reached the Moon, but when we’ve got to the stars we’ll still be no nearer that inferno four thousand miles beneath our feet.

‘I can now get recognisable echoes from two miles down, but I hope to step up the transmitter to ten megawatts in a few months. With that power, I believe the range will be increased to ten miles; and I don’t mean to stop there.’