And even today you didnt give us the warning until so late. Why?
Again there was no point, Athena said. Twenty-four hours ago nobody could be sure if the shield would work at all. Not even me! It was only when it was clear that the shield was going to save the bulk of humanity that the particle storm became worth worrying about
Gradually Bud began to understand. AIs, even Athena, while they could be far smarter than humans in many ways, were still sometimes rather primitive ethically. Athena had picked her way through the impossible moral maze that confronted her with the delicacy of an elephant trampling through a flower bed.
And she had been forced to lie. She wasnt sophisticated enough, perhaps, to be able to express her inner confusion openly, but that turmoil had shown up in other ways. Buds instincts had been right: Athena, faced with conflicts arising from deep-buried ethical parameters, had been a troubled creation.
I have always tried to protect you, Bud, Athena said gravely. Everybody, of course, but you especially.
I know, he said carefully. The most important thing now was to get through this, to find a solution to this new problem if there was one, not to disturb whatever fragile equilibrium Athena had reached. I know, Athena.
Mikhail, frowning, leaned forward. He said carefully, Listen to me, Athena. You said you had an option. You told Bud we would get through this. You know a way to beat the particle storm, dont you?
Yes, she admitted miserably. I couldnt tell you, Bud. I just couldnt!
Why not?
Because you might have stopped me.
It took a couple of minutes to extract the principle of Athenas solution. It was simple enough. Indeed, both Mikhail and Eugene knew all about the method long before the fateful stirring of the sun.
Earths van Allen radiation belts reach from a thousand kilometers above the equator out to sixty thousand kilometers from Earth. There, charged particles from the solar wind, mass ejections, and other events are trapped by the magnetosphere. This has practical consequences: satellites anywhere in the zone are continually prone to a degradation of their electrical components from the steady wind of charged particles.
But, it had been learned, it was possible to drain the particles out of the van Allen belts. The idea was to use very low-frequency radio waves to push aside the particles. At the magnetic poles they would leak out of the van Allen trap into the upper atmosphere. This principle had been exploited since 2015, when a suite of protective satellites had been set up in orbit around the belts. It didnt take much power, Bud learned now: an output of just a few watts per satellite could halve the time an electron spent in the van Allen belts.
These cleansers are kept mostly dormant, Mikhail said. But they are switched on after the most severe solar stormsoh, and after 2020, when the nuclear destruction of Lahore threw a lot of high-energy particles into the upper atmosphere.
Eugene said, Its interesting that weve never actually observed the van Allen belts in their natural state. Just after their discovery in 1958 the United States detonated two big nukes over the Atlantic, swamping the belts with charged particles. And since then, everyday radio transmissions have been affecting the speed at which the charged particles drain away
Bud held up his hand. Enough. Athena, is this how you are planning to deflect the particle storm?
Yes, Athena said, a bit too brightly. After all, the shield is like one big antenna, and it is laced with electronic components.
Ah. Mikhail turned away, murmuring to Eugene, and punched at a softscreen. Colonel, it could work. The shields electronic components are light and low-powered. But with some smart coordination by Athena, they could be used to produce pulses of very long-wavelength radio wavesas long as the shields diameter, if we wish. The particle storm is so wide we cant reach it all. But Athena could punch a hole in it, an Earth-sized hole. He checked his numbers and shrugged. It wont be perfect. But it will be pretty good, I think.
Eugene put in, Of course its the thinness of this cloud that has saved the day.
Bud didnt understand. What has the thinness got to do with it?
That means the cloud will pass quickly. And thats important. Because the shield wont survive long. Eugene said this in his usual cold, unemotional way. Do you see?
Mikhail studied Bud. Colonel Tooke, the shield was not designed for this. The power loadsthe components will be overloaded, burned out, quite quickly.
Bud saw it. And Athena?
Mikhail said bleakly, Athena wont survive.
Bud rubbed his face. Oh, girl.
Her voice was small. Did I do something wrong, Bud?
No. No, you didnt do anything wrong. But thats why you couldnt tell me, wasnt it?
When she realized she could save the Earth by throwing herself into the fire, Athena had known her duty immediately. But she had been afraid that Bud might stop herand then the Earth would be forfeitand that she couldnt allow.
She had known all this, been faced with this tangled dilemma, from the moment she had been booted up.
No wonder youve been confused, Bud said. You should have talked to us about it. You should have talked to me.
I couldnt. She hesitated. I meant too much to you.
Of course you mean a lot to me, Athena
Im here with you, while your son is stuck on Earth. Here in space, Im your family. Like your daughter. I do understand, you see, Bud. Thats why you might have been tempted to save me, despite everything else.
And you thought I would stop you because of this.
I was afraid you would, yes.
On the softscreens Mikhail and Eugene wore carefully grave expressions. Athenas grasp of human psychology was as weak as her sense of ethics, if she thought that she could ever be some kind of recompense for Buds isolation from his son. But now wasnt the time to tell her.
Bud felt his battered heart tear a little more. Poor Athena, he thought. Girl, I would never stop you doing your duty.
There was a long pause. Thank you, Bud.
Mikhail said gently, Athena, just remember that there is a copy of you, encoded into the Extirpators blast. You might live forever, whatever happens today.
It might, Athena said. The copy. But it isnt me, Doctor Martynov. Less than thirty minutes to go, she said calmly.
Athena
Im properly positioned and ready to go to work, Bud. By the way, I have sent distributed commands to my local processors. The shield will continue to function even after my central cognitive functions have broken down. That will give you a few more minutes protection.
Thank you, Mikhail said gravely.
Athena said, Bud, am I one of the team now?
Yes. Youre one of the team. You always have been.
I have always had the greatest enthusiasm for the mission.
I know, girl. You always did your best. Is there anything you want?
She paused for more than a second, an eternity for her. Just talk to me, Bud. You know I always enjoy that. Tell me about yourself.
Bud rubbed his grimy face and sat back. But you know a lot of it already.
Tell me anyhow.
All right. I was born on a farm. You know that. I was always a dreamy sort of kidnot that youd have known it to look at me
It was the longest twenty-eight minutes of his life.
48: Cerenkov Radiation
Bisesa and Myra followed the crowd to the river.
They arrived at the Thames not far from Hammersmith Bridge. The river was high, swollen with rain runoff. They were lucky not to be flooded, in fact. They sat side by side on a low wall and waited silently.