by Fred Hoyle
It was not until nearly six o’clock that Kingsley was satisfied that everything was satisfactorily in order, checked and double-checked. He made his way to the top floor of the building where the machine was housed. The heat of many thousands of valves made the machine-room pleasantly warm and dry on this cold damp January day. There was the familiar hum of electric motors and the rattle of the teleprinter.
The Astronomer Royal had spent a pleasant day visiting old friends, and a delightful evening at the Trinity Feast. Now at about midnight he felt much more like sleeping than sitting up at the Mathematical Laboratory. Still, perhaps he’d better go along and see what the crazy fellow was up to. A friend offered to take him by car to the lab., so there he was standing in the rain, waiting for the door to be opened. At length Kingsley appeared.
“Oh hello, A.R.,” he said. “You’ve come at just the right moment.”
They walked up several flights of stairs to the computer.
“Have you got some results already?”
“No, but I think I’ve got everything working now. There were several mistakes in the routines I wrote this morning and I’ve spent the last few hours in tracking ’em down. I hope I’ve got them all. I think so. Provided nothing goes wrong with the machine, we should get some decent results in an hour or two. Good feast?”
It was about two o’clock in the morning when Kingsley said:
“Well, we’re nearly there. We should have some results in a minute or two.”
Sure enough five minutes later there was a new sound in the room, the chatter of the high-speed punch. Out of the punch came a thin strip of paper about ten yards long. The holes in the paper gave the results of a calculation that it would have taken an unaided human a year to perform.
“Let’s have a look at it,” said Kingsley as he fed the paper tape into the teleprinter. Both men watched as row after row of figures were typed out.
“The lay-out isn’t very good, I’m afraid. Perhaps I’d better interpret. The first three rows give the values of the set of parameters I put into the calculations to take account of your observations.”
“And how about the position of the intruder?’ asked the Astronomer Royal.
“Its position and mass are given in the next four rows. But they’re not in a very convenient form — I said the lay-out isn’t very good. I want to use these results to calculate next what influence the intruder should have on Jupiter. This tape is in the right form for that.”
Kingsley indicated the paper strip that had just come out of the machine.
“But I shall have to do a little calculation myself before I can reduce the tabulated numbers to a really convenient form. Before I do that, let’s start the machine finding out about Jupiter.”
Kingsley pressed a number of switches. Then he put a large roll of paper tape into the ‘reader’ of the machine. After pressing another switch the reader began to unroll the tape.
“You see what happens,” said Kingsley. “As the tape is unrolled a light shines through the holes in it. The light then goes into this box here, where it falls on a photo-sensitive tube. This causes a series of pulses to go into the machine. This tape I’m just putting in gives instructions to the machine as to how it is to calculate the disturbance in the position of Jupiter, but the machine hasn’t had all its instructions yet. It still doesn’t know where the intruder is, or how massive it is, or how fast it’s moving. So the machine won’t start working yet.”
Kingsley was right. The machine stopped as soon as it had reached the end of the long roll of paper tape. Kingsley pointed to a small red light.
“This shows that the machine has stopped because the instructions aren’t complete yet. Now where’s that piece of tape we got out last time? That’s it on the table by you.”
The Astronomer Royal handed over the long strip of paper.
“And this supplies the missing piece of information. When this has gone in, the machine will know all about the intruder as well.”
Kingsley pressed a switch and in went the second piece of tape. As soon as it had run through the reader, just as the first tape had done before it, lights began to flash on a series of cathode-ray tubes.
“Off she goes. From now on for the next hour the machine will be multiplying a hundred thousand ten-figure numbers every minute. And while it does that, let’s make some coffee. I’m peckish, I haven’t had anything to eat since four o’clock yesterday afternoon.”
So the two men worked on through the night. It was greying dawn on a miserable January morning when Kingsley said:
“Well, that’s about it. We’ve got all the results here, but they need a bit of conversion before we can get to work on a comparison with your observations. I’ll get one of the girls to do that today. Look, A.R., I suggest you have dinner with me tonight, and then we’ll go over things with a tooth comb. Perhaps you’d like to slip along now and get a bit of sleep. I’ll stay on until the lab staff comes in.”
After dinner that night, the Astronomer Royal and Kingsley were again together in the latter’s rooms at Erasmus College. The dinner had been a particularly good one and they were both much at their ease as they drew up to the blazing fire.
“Lot of nonsense we hear nowadays about these closed stoves,” said the Astronomer Royal, nodding towards the fire. “They’re supposed to be very scientific, but there’s nothing scientific about ’em. The best form of heat is in the form of radiation from an open fire. Closed stoves only produce a lot of hot air that’s extremely unpleasant to breathe. They stifle you without warming you.”
“A lot of sense in that,” added Kingsley. “Never had any use for such devices myself. Now how about a spot of port before we get down to business? Or madeira, claret, or burgundy?”
“Very nice, I think I’d like the burgundy, please.”
“Good, I’ve got a quite nice Pommard ’57.”
Kingsley poured out two largish glasses, returned to his seat, and went on:
“Well, it’s all here. I’ve got my calculated values for Mars, Jupiter, Uranus, and Neptune. The agreement with your observations is fantastically good. I’ve made up a sort of synopsis of the main results here on these four sheets, one for each planet. You can see for yourself.”
The Astronomer Royal spent several minutes looking over the several sheets.
“This is most impressive, Kingsley. That computer of yours is certainly a quite fantastic instrument. Well, are you satisfied now? Everything fits into line. Everything fits the hypothesis of an external body invading the solar system. By the way, do you have the details of its mass, position, and motion? They’re not given here.”
“Yes, I’ve got those too,” answered Kingsley, picking another sheet out of a large file.
“And that’s just where the trouble arises. The mass comes out at nearly two-thirds of that of Jupiter.”
The Astronomer Royal grinned.
“I thought you estimated at the B.A.A. meeting that it would be equal to Jupiter at least.”
Kingsley grunted.
“Considering the distractions, that wasn’t a bad estimate, A.R. But look at the heliocentric distance, 21.3 astronomical units, only 21.3 times the Earth’s distance from the Sun. It’s impossible.”
“I don’t see why.”
“At that distance it must be easily visible to the naked eye. Thousands of people would have seen it.”
The Astronomer Royal shook his head.
“It doesn’t follow that the thing must be a planet like Jupiter and Saturn. It may have a much higher density and a lower albedo. That might make it a very difficult naked-eye object.”
“Even so, A.R., some telescopic sky survey would have picked it up. You see it’s in the night sky, somewhere south of Orion. Here are the co-ordinates; Right Ascension 5 hours 46 minutes, Declination minus 30 degrees 12 minutes. I don’t know the details of the sky very well, but that is somewhere south of Orion, isn’t it?”
The Astronomer Royal grinned again.
“Oh, about fifteen years ago, I suppose.”
“What happened then?”
“I had to show a party of visitors over the Observatory.”
“Well, don’t you think we ought to go up to the Observatory now and see what we can see, instead of arguing about it? It seems to me that this intruder, as we keep calling it, may not be a solid body at all.”
“You mean it might be a cloud of gas? Well, in some ways that would be better. It wouldn’t be so easily seen as a condensed body. But the cloud would have to be pretty localized, with a diameter not much greater than that of the Earth’s orbit. A pretty dense sort of cloud it would have to be too, about 10–10 gm. per cm3. A minute star in the process of formation perhaps?”
The Astronomer Royal nodded.
“We know that the very big gas clouds like the Orion nebula have average densities of perhaps 10–21 gm. per cm3. On the other hand, stars like the Sun with densities of 1 gm. per cm3 are constantly forming within the big gas clouds. This surely means that there must be patches of gas at all densities varying from say 10–21 gm. per cm3 at one extreme up to stellar densities at the other extreme. Your 10–10 gm. per cm3 is bang in the middle of this range, and looks quite plausible to me.”
“There is a great deal of truth in that, A.R. Clouds with that sort of density must exist, I suppose. But I think you were quite right about going up to the Observatory. I’ll give Adams a ring while you finish your wine, and I’ll get a taxi.”
When the two men reached the University Observatory the sky was overcast, and although they waited through the cold damp hours there was no sight of the stars that night. And so it was the following night, and the night after that. Thus did Cambridge lose the honour of the first detection of the Black Cloud, as it had lost the honour of the first detection of the planet Neptune more than a century before.
On 17 January, the day after Herrick’s visit to Washington, Kingsley and the Astronomer Royal again dined together in Erasmus. Again they made their way to Kingsley’s rooms after dinner. Again they sat before the fire, drinking Pommard ’57.
“Thank goodness we don’t have to sit up all night again. I think Adams can be trusted to ring through if the sky clears.”
“I really ought to be getting back to Herstmonceux tomorrow,” said the Astronomer Royal. “After all, we’ve got telescopes there too.”
“Evidently this damn weather has got you down the same as me. Look here, A.R., I’m in favour of throwing our hand in. I’ve drafted a cable to send to Marlowe in Pasadena. Here it is. They won’t be troubled by cloudy skies over there.”
The Astronomer Royal glanced down at the sheet of paper in Kingsley’s hand.
PLEASE INFORM WHETHER UNUSUAL OBJECT EXISTS AT RIGHT ASCENSION FIVE HOURS FORTY-SIX MINUTES, DECLINATION MINUS THIRTY DEGREES TWELVE MINUTES. MASS OF OBJECT TWO-THIRDS JUPITER, VELOCITY SEVENTY KILOMETRES PER SECOND DIRECTLY TOWARDS EARTH. HELIOCENTRIC DISTANCE 21.3 ASTRONOMICAL UNITS.
“Shall I send it?’ asked Kingsley, anxiously.
“Send it. I’m sleepy,” said the Astronomer Royal, good-naturedly stifling a yawn.
Kingsley had a lecture at nine a.m. the following morning, so he bathed, dressed, and shaved before eight. His ‘gyp’ had laid the table for breakfast.
“A wire for you, sir,” he said.
A quick glance showed the ‘wire’ to be a cable. Incredible, thought Kingsley, that they should have a reply so quickly from Marlowe. He was even more astonished when he opened the cable.
IMPERATIVE YOU AND ASTRONOMER ROYAL COME IMMEDIATELY REPEAT IMMEDIATELY TO PASADENA. CATCH 15.00 PLANE TO NEW YORK. TICKETS AT PAN AMERICAN, VICTORIA AIR TERMINAL. VISA ARRANGEMENTS AT AMERICAN EMBASSY. CAR WAITING LOS ANGELES AIRPORT. HERRICK.
The aircraft climbed slowly, heading westwards. Kingsley and the Astronomer Royal relaxed in their seats. It was the first moment of ease since Kingsley had opened the cablegram that morning. First he had to postpone his lecture, then he had discussed the whole matter with the Secretary of the Faculties. It was not easy to leave the University at such short notice, but eventually it was arranged. By then it was eleven a.m. This left three hours to get to London, fix his visa, collect the tickets, and board the bus from Victoria to London airport. It had been something of a rush. Things were a little easier for the Astronomer Royal, who travelled abroad so much that he always had passports and visas ready for just such an emergency.
Both men pulled out books to read on the journey. Kingsley glanced at the Astronomer Royal’s book and saw a vivid cover featuring a gun fight among desperados.
“Heaven knows what he’ll be reading next,” thought Kingsley.
The Astronomer Royal looked at Kingsley’s book and saw it was Herodotus’ Histories.
“My God, he’ll be reading Thucydides next,” thought the Astronomer Royal.
Californian Scene
It is necessary now to describe the consternation that Kingsley’s cablegram produced in Pasadena. A meeting was held in Herrick’s office the morning after his return from Washington. Marlowe, Weichart, and Barnett were there. Herrick explained the importance of arriving quickly at a balanced view of the effects that the arrival of the Black Cloud would have.
“The position we’ve arrived at is this: our observations show that the cloud will take about eighteen months to reach us, or at any rate this seems rather likely. Now, what can we say about the cloud itself? Will there be any significant absorption of the Sun’s radiation when it comes between us and the Sun?”
“That’s very difficult to say without more information,” said Marlowe, puffing smoke. “At the moment we don’t know whether the cloud is just a tiny fellow quite close to us or whether it’s a biggish cloud farther away. And we’ve got no idea at all of the density of the material inside it.”
“If we could get the velocity of the cloud, then we should know how big it is and how far away,” remarked Weichart.
“Yes, I’ve been thinking about that,” went on Marlowe. “The Australian radio boys could get the information for us. It’s very likely that the cloud consists mainly of hydrogen, and it should be possible to get a Doppler shift on the 21 cm line.”
“That’s a very good point,” said Barnett. “The obvious man is Leicester in Sydney. We ought to get a cable off to him right away.”
“I don’t think that’s quite our job, Bill,” Herrick explained. “Let’s stick to what we can do ourselves. When we’ve sent in our report, it’ll be Washington’s job to contact the Australians about radio measurements.”
“But surely we ought to make a recommendation about getting Leicester’s group on to the problem?”
“Certainly we can do that, and I think we ought to. What I meant was that we ought not to initiate action of this sort. The whole business is likely to have serious political implications, and I feel that we ought to keep away from such things.”
“Right enough,” broke in Marlowe; ‘politics is the last thing I want to get involved in. But obviously we need the radio boys to get the velocity. The mass of the cloud is more difficult. As far as I can see the best way, perhaps the only way, would be from planetary perturbations.”
“That’s pretty archaic stuff, isn’t it?’ asked Barnett. “Who do it? The British, I suppose.”
“Yes, h’m,” murmured Herrick, “perhaps we’d better not emphasize that aspect of the matter. But the Astronomer Royal probably would be the best person to approach. I’ll make a point of it in the report, which I ought to start on as soon as possible. I think we’re agreed on the main points. Does anyone want to bring up anything further?”
“No, we’ve gone over the ground pretty thoroughly, as far as we can go, that’s to say,” answered Marlowe. “I think I’ll be getting back to one or two jobs that I’ve rather neglected during the last few days. I expect you’ll want to get that report finished. Glad I don’t have to write it.”
And so they
filed out of Herrick’s office, leaving him to get down to his writing, which he did forthwith. Barnett and Weichart drove back to Caltech. Marlowe went to his own office. But he found it impossible to work, so he strolled along to the library where there were several of his colleagues. A lively conversation of the colour-magnitude diagram of the stars of the galactic nucleus contrived to pass the time until it was generally agreed that the lunch hour had arrived.
When Marlowe returned from lunch the Secretary sought him out. “Cablegram for you, Dr Marlowe.”
The words on the piece of paper seemed to swell to a gigantic size:
PLEASE INFORM WHETHER UNUSUAL OBJECT EXISTS AT RIGHT ASCENSION FIVE HOURS FORTY-SIX MINUTES, DECLINATION MINUS THIRTY DEGREES TWELVE MINUTES. MASS OF OBJECT TWO-THIRDS JUPITER, VELOCITY SEVENTY KILOMETRES PER SECOND DIRECTLY TOWARDS EARTH. HELIOCENTRIC DISTANCE 21.3 ASTRONOMICAL UNITS.
With a startled cry Marlowe raced along to Herrick’s office, and burst in without the formality of a knock.
“I’ve got it here,” he shouted. “All the things we wanted to know.”
Herrick studied the cablegram. Then he smiled somewhat wryly and said:
“This alters things quite a bit. It looks as though we shall have to consult with Kingsley and the Astronomer Royal.”
Marlowe was still excited.
“It’s easy to diagnose the situation. The Astronomer Royal has supplied observational material on the planetary motions and Kingsley has done the calculations. If I know those two fellows there isn’t much chance of a mistake there.”
