Fred Hoyle: The Black Cloud

KINGSLEY’S DRAWING OF SITUATION IN SIXTEEN MONTHS’ TIME

“It looks to me as if we’re rather lucky,” Barnett laughed uneasily. “Because of the Earth’s motion round the Sun, the Earth will be on the far side of the Sun sixteen months hence when the Cloud arrives.”

“That only means that the Cloud will reach the Sun before it reaches the Earth. It won’t stop the sunlight being blocked out if the Sun gets covered, as in Kingsley’s case ( a ),” Marlowe remarked.

“The point about your cases ( a ) and ( b ),” said Weichart, “is that you only get case ( a ) if the Cloud has almost exactly zero angular momentum about the Sun. It only needs a very slight angular momentum and we have case ( b ).”

“That’s exactly it. Of course my case ( b ) was only one example. The Cloud could equally well sweep past the Sun and the Earth on the other side, like this:”

“Do we have anything to say about whether the Cloud is coming dead at the Sun or not?’ asked Herrick.

“Not on the observational side,” answered Marlowe. “Look at Kingsley’s drawing of the present situation. Only a very slight difference of velocity makes a big difference, all the difference between the Cloud hitting and missing. We can’t say yet which it’s to be, but we can find out as the Cloud comes in nearer.”

“So that’s one of the important things to be done,” concluded Herrick.

“Can you say anything more from the theory?”

“No, I don’t think we can; the calculations aren’t accurate enough.”

“Astonishing to hear you distrusting calculations, Kingsley,” remarked the Astronomer Royal.

“My calculations were based on your observations, A.R.! Anyway I agree with Marlowe. The thing to do is to keep a close watch on the Cloud. It should be possible to see whether we’re going to have a hit or a miss without too much trouble. A month or two should settle it, I suppose.”

“Right!’ answered Marlowe. “You can rely on us to watch this fellow from now on as carefully as if it was made of gold.”

After lunch Marlowe, Kingsley, and the Astronomer Royal were sitting in Herrick’s office. Herrick had explained the plan of writing a joint report.

“And I think our conclusions are very clear. May I just outline them for you?

1. A cloud of gas has invaded the solar system from outer space.

2. It is moving more or less directly towards us.

3. It will arrive in the vicinity of the Earth about sixteen months from now.

4. It will remain in our vicinity for a time of about a month.

“So if the material of the Cloud interposes itself between the Sun and the Earth, the Earth will be plunged into darkness. Observations are not yet sufficiently definitive to decide whether or not this will occur, but further observations should be capable of deciding this question.”

“And I think we can go a little further concerning future observations,” Herrick went on. “Optical observations will be prosecuted here with all energy. And we feel that work by the Australian radio astronomers will be complementary to ours, particularly with regard to keeping a watch on the line of sight motion of the Cloud.”

“That seems to sum up the situation admirably,” agreed the Astronomer Royal.

“I propose that we proceed with the report at full speed, that we four sign it, and that it be communicated to our respective Governments forthwith. I hardly need say that the whole matter is highly secret, or at least that we should treat it as so. It is rather unfortunate that so many are aware of the position, but I believe that we can rely on everybody proceeding with great discretion.”

Kingsley did not agree with Herrick on this point. Also he was feeling very tired, which no doubt made him express his views rather more forcibly than he would otherwise have done.

“I’m sorry, Dr Herrick, but I don’t follow you there. I see no reason why we scientists should go to the politicians like a lot of dogs thumping our tails, saying “Please, sir, here’s our report. Please give us a pat on the back and perhaps even a biscuit if you feel so disposed.” I can’t see the slightest point in having to do with a crowd of people that can’t even run society properly during normal times when there’s no serious stress. Will the politicians pass statutes to stop the Cloud coming? Will they be able to prevent it cutting off the light of the Sun? If they can, then consult them by all means, but if they can’t, let’s leave them out of the picture altogether.”

Dr Herrick was quietly firm.

“I’m sorry, Kingsley, but as I see it the United States Government and the British Government are the democratically elected representatives of our respective peoples. I regard it as our obvious duty to make this report, and to maintain silence until our Governments have made a pronouncement on it.”

Kingsley stood up.

“I’m sorry if I seem brusque. I’m tired. I want to go and get some sleep. Send your report if you wish, but please understand that if I decide to say nothing publicly for the time being, it will be because I wish to say nothing, not because I feel under any form of compulsion or duty. And now if you’ll excuse me, I’d like to get round to my hotel.”

When Kingsley had gone, Herrick looked at the Astronomer Royal.

“Dr Kingsley seems a trifle … er …”

“A trifle unstable?’ said the Astronomer Royal. He smiled and went on:

“That’s not very easy to say. Whenever you can follow his reasoning, Kingsley is always very sound and often brilliantly deductive. And I am inclined to think this is always so. I think he seemed rather odd just now because he was arguing from unusual premises, rather than because his logic was faulty. Kingsley probably thinks about society in quite a different way from us.”

“Anyway I think that while we work on this report it would be a good idea if Marlowe were to look after him,” remarked Herrick.

“That’s fine,” Marlowe agreed, still struggling with his pipe, “we’ve got a lot of astronomy to talk about.”

When Kingsley came down to breakfast the following morning he found Marlowe waiting.

“Thought you might like to drive out for the day into the desert.”

“Spendid, there’s nothing I’d like better. I’ll be ready in a few minutes.”

They drove out of Pasadena, turned sharply right off Highway 118 at La Canada, then cut through the hills, past the side road to Mount Wilson, and so on to the Mohave Desert. Three more hours’ driving brought them under the wall of the Sierra Nevada, and at last they could see Mount Whitney plastered with snow. The far desert stretching towards Death Valley was veiled in a blue haze.

“There are a hundred and one tales,” said Kingsley, “of what a man feels like when he’s told that he’s only got a year to live — incurable diseases, and so on. Well, it’s odd to think that every one of us probably only has a little more than a year to live. A couple of years hence, the mountains and the desert will be much the same as they are now, but there’ll be no you and me, no people at all to drive along through it.”

“Oh my God, you’re much too pessimistic,” grunted Marlowe. “As you said yourself, there’s every chance that the Cloud will sweep to one side or the other of the sun, and give us a complete miss.”

“Look, Marlowe, I didn’t want to press you too much yesterday, but if you’ve got a photograph going back a number of years you must have a pretty good idea of whether or not there’s any proper motion. Did you find any?”