Petrie taps at his jacket. ‘I have the advance guard right here in my pocket. But it’s not a physical invasion. It’s an invasion of ideas.’
There is a long, strained silence. Petrie, owl-like behind his round spectacles, forces a brief, nervous smile. Alice leans back in her chair. ‘I’m sorry, but that’s just off the wall.’ She turns to Callaghan. ‘I think we should turn him in.’
Callaghan is peering thoughtfully into Petrie’s eyes. ‘Keep talking, Tom.’
Petrie shakes his head in frustration, like a man lacking the words to get his thoughts over. He sits down again. ‘Imagine a world where countries are always at war with each other. So, war is good. War forces change, drives technology, sweeps away dead wood and so on. But as technology advances it reaches a point where it’s so destructive that societies crash if they go to war. At that stage things can go one of two ways. Either they keep going back to the Stone Age, or they get through the threshold by developing some code for living together.’
‘Where did you get that from? Out of some CND pamphlet?’
‘Now if you’re on a planet that doesn’t get through the barrier, you don’t matter. You keep going back to the Dark Ages and that’s that. But if you break that threshold, if you evolve a moral code which makes war impossible, there’s no stopping you. You just keep growing in technology and knowledge. Survival of the fittest selects those civilisations. Until they hit the next barrier.’
‘Which is?’
‘Your first extraterrestrial contact. Then natural selection works just like before, only on a different scale of space and time. Now it’s planets instead of countries but the same rules apply. On the long term the choice is still between mutual destruction or mutual sharing of some moral code which allows survival.’
‘With you so far. The good guys win through.’ Callaghan is humouring a lunatic. ‘Don’t quite connect it with this alien signal, though.’
‘Right. Right.’ Petrie blinks in surprise, as if he thinks the connection is self-evident. ‘Okay, here’s a question that bugged us from the day we got the signal. Why did they contact us? They don’t need us, not for food, not for their test tubes. We’re too primitive to be of any interest to them.’
‘They just want to be nice to us?’ Callaghan suggests.
‘They want us to survive, for their own reasons. And to survive they want us to adopt a particular complex of ideas because that’s our best chance of survival. If we don’t, we become a threat to them, maybe a thousand years down the line, maybe just a hundred. They need us to evolve towards their values and morality because it’s their best protection.’
‘Otherwise we might turn into Vikings or something?’
Petrie nods. ‘Exactly. And if we don’t respond, we’re a potential threat to the signal. Not now, but in the future. I don’t know how they handle a threat.’
Callaghan is struggling. ‘Excuse me, did I hear you say we could become a threat to the signal?’
‘Yes, Joe, the signal. It propagates, it grows, it evolves by natural selection, it communicates. By any reasonable definition it’s a living thing. It’s infinitely powerful because it contains all knowledge. And it uses life forms as its medium of storage. I guess that’s why it wants us to survive and prosper. Life is rare and precious.’
Alice says, ‘You’re a nutcase.’
Petrie grins desperately. ‘And I’ve been running amok with an axe. You know what Darwin said? He said the chicken is the means by which the egg reproduces itself. The egg has all the information it needs to make the chicken. The information is stored in the DNA but the storage medium doesn’t matter — it can be molecules or silicon chips or paper tape. The knowledge is what matters. You can encode life in a string of letters, you could even reduce it to Morse code.’
‘Now hold on, a musical score ain’t music,’ Callaghan objects.
‘Excellent point, Joe, on the button. You need an instrument to play a tune, and the signal needs life forms to propagate itself. Signal and life need each other like the chicken and egg need each other.’
‘The invaders are ideas? Not guys in spacesuits?’
‘There’s no point in interstellar travel because civilisations don’t need it. With the information content in these particle flows you don’t have to visit alien worlds, you could recreate them in virtual space. The signal outstrips any conceivable spaceship. At the speed of light, information can cross the Galaxy in fifty thousand years.’
‘Still a helluva time.’
‘Joe, it’s a lot less than the lifespan of a primate species. Expand your mind. Anyway the nearest signallers could be next door. We’re just four hundred years from Antares, two hundred from Betelgeuse, eight years from Sirius and four months from the Oort cloud.’
‘Let me get this right — the invaders are ideas?’ Callaghan asks.
‘The life forms stay nice and cosy in their own planetary system or whatever. They might be organic life forms like us, or machines or computers or molecules, but so far as the signal is concerned, life is just a storage medium. The signal is the real living entity.’
‘The signals have colonised the Galaxy,’ Callaghan repeats. He is still struggling with the concept.
‘Not guys in spacesuits, not even machines. The colonisers are imperialistic, all-conquering complexes of ideas and information bound together by a moral code which ensures mutual survival of life forms — organic life or machine descendants — because without life forms to transmit it, the signal itself would die.’
‘Gentle Jesus, I’m just a Trade Adviser.’
Alice asks, ‘Are we supposed to believe that this signal is a living entity or what? Is it a spiritual thing?’
‘I don’t know. It encompasses all knowledge. It evolves and reproduces itself and acts to protect itself. It inculcates its baby — life — with the moral code it needs for its own survival and that of life. It pervades the Galaxy.’
‘Maybe even beyond?’ Alice suggests. ‘Making the Universe a living thing?’
Petrie grins again. ‘You’re getting into the spirit, Alice. Maybe our Galaxy has been seeded, maybe genetic material drifts around like spores, I don’t know. Some of it takes, some of it doesn’t. But just as soon as any garbage civilisation crawls out of the caves and learns the most primitive biochemistry, the signallers fire off a blueprint for survival.’ His eyes are gleaming. ‘There’s a Galactic club out there. It’s a paradise club, it’s immortality. The signal is an invitation to join.’
The President put his beer can on a coffee-table, still unopened. He contemplated it for a few seconds, sighed, looked up and grinned. ‘Yep, I’ve finally heard it all.’
The CIA Director said, ‘Seth, if you were trying to beat a murder rap, would you come up with a yarn like that?’
43
The Oort Cloud
‘Now just so we can get the complete background, Tom — why the murder?’
‘It was self-defence. He was sent to kill us all.’
‘Ah yes — “they’re out to get me”. You told me that. Who is out to get you, Tom? The Slovaks? The aliens?’
‘Sneer away, Joe, but I have the evidence right here in my pocket.’ Petrie taps at his casual jacket. ‘I think my own government wants me dead, maybe the Russians too.’
‘At the risk of asking the obvious…’
‘My guess is they still have a pre-emptive strike mentality. They think we should keep our heads down. If we reply, it’s telling the signallers that we’re approaching a technological stage where we could become a risk to them maybe a few centuries down the line. They think the signal could be a lure to flush out civilisations like us in order to remove us.’