31

People stood to get drinks and food, or just to stretch their legs. And there were side conversations. Vasta, Smith, Hild huddled over a console, murmuring about heat flows and ‘illuminated interstellar sectors’ …

Salma got some water for herself and Feathers – and seedcake for Feathers alone, one of Meriel’s many minor biological miracles, created over the years.

Feathers herself wasn’t scared, exactly, Salma knew, just wary. If something alarmed her she would sit still, preferably in the shadows or on the periphery of a group but not outside it, as if seeking not to be seen, and with somewhere to escape to if she needed it. Meriel said it was the typical behaviour of a creature in the middle of a food chain, adapted to being both predator and prey. Another small clue to Feathers’ background.

The avatar of the President sat silent and still during the break. Salma wondered if she, it, were even activated. How strange, Salma thought, to have the most significant human being on all the planets represented this way, and shut down, an outsider to the conversations. But it was probably good for those present to be able to relax a little without that scrutiny.

At last, after about thirty minutes, the avatar leaned forward in her unreal chair, froze again.

That was evidently enough of a command to draw the group together again. People started to drift back into their places, some carrying drinks, others portable data consoles over which arguments continued.

Emmanuel Caspar came over to Salma with his drink. He asked softly, ‘So what do you think of the President? I mean, I’m a mere captain of an interplanetary liner – and I ran a tiny colony at Saturn. That was tough enough. This is what I’d call command. And, listen, do you think Feathers is OK with all this talk-talk? I know she can’t understand a word – can she? If she’s distressed in any way, you don’t have to leave; I could get Fabio to come take her away, look after her. They get on well, don’t they?’

‘Sure.’ Salma thought it over. ‘It’s a kind offer. Thoughtful. Yes, I know Fabio is good with her. But—’

‘What?’

She looked around at the group. ‘This is such a big meeting. The President of Earth! Or her avatar anyhow. And it’s about the strange situation that brought Feathers here in the first place. I have this feeling that she ought to be here – even if she doesn’t follow any of it. In fact she could clearly never understand any of this.’

He nodded. Quite a situation, isn’t it? But, yes, I guess you’re right, she should be here if only for what she stands for …’

‘I think we’ve come to believe that that’s why she was sent here. Because she is a walking, living symbol of something else. She stands for something bigger. And what we have to do is to work out what that is …’

Hild coughed, politely.

They saw they were the last standing. They exchanged hasty smiles, joined the circle, and took their seats facing the virtual President.

Who suddenly seemed to spring to life again, as if a switch had been thrown.

‘OK,’ Mason began. ‘I think we’re nearly done for now.’

‘Not a long meeting,’ Salma whispered to Caspar.

‘Presidents are busy people. Even their avatars are busy, I guess …’

Mason was saying, ‘but I do still have some specific questions.

‘I would like you to confirm something for me. Right at the beginning of all this, eleven years ago – when this quasar first lit up – the warming effects on the Earth were immediately apparent. But what about the question of how long we will be in the eye of this heat storm – how long before we might be free of it? I was shown some numbers back then, at the beginning. I’d like to know if the logic behind that prediction has changed, or not.’

Vasta took the lead. ‘OK, Madam President. You want to know how long the Earth, and the wider Solar System, might be threatened by this phenomenon, this – custom quasar.’

Mason smiled. ‘The Custom Quasar. You can use that as the title of your book some day.’

‘Let’s hope there is such a day. But in the meantime – all we have is order of magnitude arguments, I’m afraid. Still.

‘So, look, we can take the Earth’s insolation, the sunlight energy it receives, as a starting point. A basis for scaling. And we know the quasar intensity is increasing, still. So suppose the ultimate purpose of the quasar is indeed to deliver an extra amount of energy to Earth equivalent to that solar energy density, per unit area. At least that’s an order of magnitude to play with.’

Mason shrugged. ‘Like Venus again? That seems a reasonable benchmark – and lethal enough, from what you say.’

‘OK. But we know that the quasar beam doesn’t just target Earth. That’s probably impossible, given the smallness of the target, the distance. So we are passing through the spot, a wider beam.

‘Now, the energy flow has been measured, by spacecraft across the Solar System – out to here, the most remote crewed station, and further by the robot probes. And it appears to have the same energy density right across the Solar System. No fall-off. Presumably the total spot is much wider still. How much wider is the question. And what does it take to produce that much energy, projected right out here, far from the Galaxy’s centre?’

She looked down at her console. ‘So, look – the most powerful quasar we know of – in nature that is, before the Milky Way quasar showed up – produces as much energy as you could get from extracting the mass-energy of the Moon, every second. Suppose the core quasar is as energetic as that.’

She got some gasps at that, but smiled and pushed on.

‘Now, with all that energy output pouring out towards the Solar System – and if the, the spotlight beam spreads out so far that it’s down to Earth-sunlight intensity across that whole range … well, you find that the area saturated with such energy, given such a source, is somewhere around seventy light-years in radius. Which is, what, nearly twenty times further than the nearest star? If we’re somewhere near the centre of the beam, it should in fact be covering a few thousand other stars and stellar systems in our neighbourhood. That may sound a lot but it’s actually a pretty tight beam, given that it crosses a galactic radius.’

Mason said, ‘So many stars … I know this is all guesswork, but doesn’t it seem kind of hubristic that all this energy, all those star systems, are being perturbed just because of us? … And how do we know it is us who’s the target? Why just us?’

This time Salma spoke up, sitting with Feathers. ‘But we do know it is just because of us. Don’t we? We have Feathers. It started when we opened the box …’

Mason nodded. ‘Fair enough.’

Vasta said, ‘So, the question of how long we might have this quasar light inflicted on us? The Sun orbits the Galaxy core – the stars swim around the centre like shoals of fish, as I read once … So we are swimming through the quasar spot. That’s a big spot, and, given the Sun’s rate of motion, if we have to sail across the whole of the beam we won’t get out for two hundred thousand years. Give or take.’

Mason nodded. ‘The same estimates as a decade ago, when all this started. So you’ve only firmed up the case. I suppose there’s a still worse possibility – that the beam might be redirected to follow the Sun as it moves across the background.’

Vasta shrugged. ‘Perhaps. That could be. I suppose I’m conditioned to think in terms of natural phenomena, not a directed – weapon. But that’s clearly not impossible. They would know the Sun’s path … If so there’s not necessarily any upper boundary on how long we might suffer this. But hundreds of thousands of years is bad enough.’

‘All right. So that’s far longer than is needed to reach the Venus state you described – twice the intensity in a thousand years or more, you said?

‘Next question – what happens before that? Given it’s a gradually increasing heat intensity, can you give me more milestones?’

Vasta consulted a screen. ‘In fact we have some data, or at least projections, to build on from other studies. Most of you probably know about this – and you may well have seen this before, Madam President. We know that the Sun was gradually warming already – I mean, even before the quasar – through its own internal evolution, the depletion of its core fuel … If we wait long enough, the Earth will be scorched anyhow, quasar or not.

‘But this increasing quasar input will do huge damage much faster than that.’ She looked again at the screen on her lap. ‘Venus-Earth is perhaps thirteen centuries away. But, after just a hundred years, the total insolation hitting Earth – solar and quasar – will be up by five per cent on today’s figure. In nature, because of the Sun’s own slowly increasing heating – its natural heating – we’d have reached that threshold anyhow – but not until five hundred million years in the future. And we’ll get consequences surely similar to the projections we have for that far date.

‘It might not sound much, but much more of Earth’s water, for example, will start evaporating, will linger in the air rather than fall back as rain – and we’ll get even more heating from that, by the way; water in the air acts a greenhouse gas.

‘Meanwhile the carbon dioxide cycle will start breaking down. The overheated, exposed rocks will weather, cracking, reacting with the carbon dioxide in the air, drawing it down … You might think less carbon dioxide is good, because less warming. Yes, but vegetation needs carbon dioxide to survive. The most advanced photosynthesising plants will wither first, without the cee oh two from which they extract carbon to build trunks and leaves. The herbaceous plants, deciduous trees, evergreen broad-leaf trees, even some conifers – most of our crop plants too – all gone.’

‘All this after the first century?’

‘All this after the first century. In the decades after that, extinctions on a massive scale will follow – whole domains of life. Photosynthesis itself will eventually collapse. You might still get a few termites and such around the hydrothermal vents at the bottom of the oceans.

‘But by two hundred years there will be a final “runaway greenhouse”, as they call it, as all the water evaporates. The oceans gone. And life will dwindle further, until—’

‘I think that’s enough. Thank you. All this if we stay in that damn quasar beam, and if it keeps strengthening as it has so far …’

‘That was a tough listen, Madam President. I suspect it’s going to be a lot more complicated than that, in good and bad ways. Earth’s systems have a lot of inertia, and a lot of complexity … But in essence, similar projections we made a decade ago haven’t changed.’

Mason shrugged. ‘But in a way the details don’t matter. For sure it’s going to be a tough tag-line when I run for re-election.’

If that was a joke, Salma thought, nobody was laughing.

Doria Bohm was exploring her own tablet. ‘And don’t forget the rest of us. Earth, with the richest biosphere, may be the most vulnerable and will suffer the most – but the other worlds will be damaged too. We on the Moon might survive in deep lunar caves with ultra-strict recycling. Any life on Mars we haven’t yet managed to destroy will be lost when the deep, ancient aquifers finally burst and dry. The ice giants will melt. Oh, I just found an estimate: Ceres will be melting after about twelve thousand years—’

‘The comets,’ Hild said. ‘In the Oort cloud. We will surely lose those quickly, given how disrupted each can be by the heat of a single passage past the Sun, lasting a few months of close approach …’

Salma had more or less followed these arguments, had heard some of it before over the years. But now, hearing it all set out so forcefully, so clearly, she felt overwhelmed. Was she going to live to see the end of the world – of all the solar worlds?

She curled over herself, knees tucked up against her chest, arms beside her head, a childish pose she should long have grown out of.

Hesitantly at first, Feathers put her long, fragile arms around her friend’s shoulders, and hugged. Salma could smell her, the wood-burn tang of the feathers, heard their soft rustling.

Salma hugged back. ‘I love you,’ she murmured.

And Melanie Mason held up an unreal hand.

The chattering, the morbid speculation, stopped.

Everybody came to order.

‘Thank you,’ Mason said now. ‘I’ve pushed you a long way here, into speculating about stuff you really don’t know much about. I know scientists don’t like to do that, and I appreciate it. This has been hugely useful – even if, I suspect, my principal will want to run it all through a dozen think-tanks to confirm it. But we are emphatic that none of this is in any sense your fault. You of the Shadow. There was a button to be pushed here; whoever got here first would have pushed the damn thing.

‘But – I know the President is going to ask, because I would ask – what the hell are we going to do about this now? Or, more to the point, what are you going to do? Because you are the ones on the spot.’

‘Nothing more without authorisation,’ Hild said, looking around the group. ‘I mean, from everybody. From all our – nations. Earth, Moon, Conservers. This is too big for our petty factionalism. Agreed?

‘But as to what we could actually do now, given authorisation – the next step seems obvious. We try sending the new Hawking signal, to this world. On behalf of mankind. One step up from the simple echo we sent before. Maybe, if they know we’re here, we’ll be spared … Or not. Anyhow we deal with whatever follows. We, the crew.’ She glanced around once again. ‘If this audience is done let’s start planning. And send that signal, since it’s all we’ve got.’

Melanie Mason nodded. ‘Wait for my authorisation – my principal’s, once she’s absorbed all this … That’s going to take days, of course. Lightspeed. And I should consult the Conserver councils, the Moon. But I think you could get on with your preparation for now. And then – well, we do what we can. Thank you again. Let’s hope we can make sense of all this.’

Caspar grinned. ‘And save the Solar System?’

‘Ideally.’ And the President of Earth winked out of existence.