John nodded. ‘That’s exactly the right way to put it. It’s just as if there was a big antenna, measuring ten times the radius of the Sun. Apparently it’s beaming a message out into space.’
There was silence for a while.
‘What would be the directivity, with an antenna as large as that?’ asked another of the officers.
‘At a big distance, quite fantastic. The beam would go out into space as an extremely fine pencil.’
Someone had a bright idea.
‘What’s the chance of our being in the direct beam?’
‘Remembering that we are in the near-field, it works out at somewhere between one in ten and one in a hundred, provided the beam is directed more or less along the ecliptic. Less than that if it’s directed at random.’
‘Isn’t it a bit surprising that we just happen to lie in it?’
‘We’re not necessarily lying in the main lobe. I’ve thought quite a lot about this point. From a climatic point of view, I mean.’
John had their attention now.
‘There must be something like a ten per cent difference in the solar radiation according to whether we’re in the main beam or not. Of course we can’t know anything directly about this infra-red stuff down here on the surface of the Earth. The infra-red never gets through the atmosphere. But it would have the effect of increasing the boundary temperature of the Earth.’
‘By how much?’
‘Anything up to ten degrees I would say. What I’ve been wondering is whether all the mysterious climatic fluctuations the Earth seems to suffer—the ice-ages for instance—could be caused by our relation to this beam. You know, it may not always point in the same direction. Sometimes the Earth could pass through it, during the year I mean. At other times we might miss it entirely.’
Clementi made a kind of humming sound. He wasn’t winking. ‘A few degrees up, or a few degrees down, is really all that might be needed to make quite big changes of climate. It could be at that. But look here, John, old chap, old fellow, old scoundrel more like, are you hinting that this deal up there might have been going on for thousands of years?’
‘I should have thought it extremely likely. If it was something that had just started up right now, well, wouldn’t it be ridiculously improbable?’
‘Yeah, I suppose so.’
Several of the men were pacing like caged beasts up and down the lounge floor.
There was a silence which everybody seemed reluctant to break. At last, the naval officer with the blue eyes spoke:
‘Gentlemen, it’s time we came to the real issues. I don’t know whether my colleagues and I can be described as having anything more than a watching brief here. But the questions that stand out in my mind are, first, how’s it being done, second, what’s it for? I must admit I’m personally in a smoke screen but maybe Dr Sinclair has something he’d like to add.’
This was quite a formal speech. I wondered how John would react to it. He shrugged his shoulders and began:
‘I think anybody’s guesses are as good as anybody else’s at this stage. For myself I can’t remotely conceive how this phasing trick is being worked. But being worked it surely is, so for the moment we’d better accept that, and go on from there—if we can. We’ve tested the deduction that the beam is being used to convey information.’
‘What information? What the hell is there to send, where and to whom?’
One of the army officers grinned and suggested, ‘Maybe it’s a TV relay.’
Most of them laughed at this. I noticed John didn’t. When the laughter had died down he simply said, ‘Could be.’ Everybody looked at him, so he went on:
‘It may sound crazy but what else can it be? Oh, I don’t mean a TV relay strictly. Think of the colossal amount of information that’s probably being sent out, of the order of a hundred million bits a second. In a year, that’s several thousand trillion bits. Something like a hundred million textbooks a year. What sort of traffic would you need to fill a channel like that?’
‘You mean there’d be no point in sending out such a lot of stuff unless there was really something to send?’ Everybody laughed at this.
After a further short pause John went on:
‘There are two speculative possibilities. This might be an interstellar, or even an intergalactic, relay station. Granted the enormous directionality of the system, the fineness of the pencil beam, these signals could be received at an enormous distance away from us.’
Clementi had obviously been thinking along the same lines. ‘The details really aren’t as fantastic as the thing itself. But as John says, we know the thing exists, so there’s no getting away from it. It’s easy enough to do an intensity calculation. If this really is a relay station, if some guy at the other end has even a moderately sensitive detecting device, say only a millionth part as sensitive as our big radio telescopes—as this thing out on the hillside here—then these signals can be picked up—where? Come on, freshman physics! Not just in our own galaxy, but anywhere, out and beyond anything we can see with the biggest telescopes.’
‘You mean this is just about the most…’ The naval officer broke off whatever it was he was going to say. It was clear to him, as to me, that the wonders of science had gone beyond all reasonable bounds.
I was back in my room that night, jotting down one or two musical ideas, when John tapped on my door. ‘Would you like to go for a stroll?’
We slipped out of a side door.
‘I don’t want any of the others to join us just for the moment.’
We had walked along for two or three hundred yards before he came to the point:
‘I’ve been thinking it would be a good idea if you were to write everything down. I mean from the beginning. I think it would be a good idea to have an account from an unbiased person.’
‘You mean a non-scientist?’
‘If you like to put it that way, yes.’
My story is built from notes as I made them following this incident. Unfortunately my diary wasn’t remotely detailed enough as it has turned out. So perforce I have often had to fill in as best I can from memory—this will explain how it comes about that sharp accounts of what took place are sometimes juxtaposed with obvious lapses of memory—my failure to recollect odd names for instance.
I began to see now why John had more or less press-ganged me into coming along with him. I also felt freer to ask questions with a clear conscience.
‘It’s all very well to avoid the problem of how this incredible thing is being done but do you have any idea at all about what’s really happening?’
We walked on for a little way.
‘Not with any precision. The obvious inference is that someone is doing it. I suppose the most straightforward explanation would be to say that it’s some creature, some intelligence, on one of the other planets.’
‘A major boost to the space programme—eh?’
‘As you say, a major boost to the space programme.’
I guessed that John really didn’t believe this. When I asked him point blank he replied:
‘It’s an outrageous explanation fitted to a fantastic situation. Yet anything else seems worse. It’s all a question of the way you look at it. When something really new happens most scientists take the line of least resistance. They accept the explanation that involves the least change from their preconceived notions. Which is what I’m doing now.’
‘But you don’t believe it?’ I pressed.
‘With me, believing or not believing a particular explanation is more a matter of method than of emotion. If I were emotional I’d be almost certain to plump for what I’ve just told you. The way I always work is like this. If I find things turning out much as I expect then I follow the line of least resistance, exactly the same as everyone else. But if I find my deductions going wildly wrong it’s my instinct to explain my shortcomings by saying that I just haven’t got hold of the right idea at all. I don’t try to do a patchwork job, to choose the explanation that requires the least possible change from my previous position. I throw the net wide, just as wide as I can.’