Diaspora

How? Karpal suddenly recalled an old idea which he'd briefly considered as an explanation for the minor anomalies. Individual neutrons were always color neutral: they contained one red, one green and one blue quark, tightly bound. But if both cores had "melted" into pools of unconfined quarks able to move about at random, their color would not necessarily average out to neutrality everywhere. Kozuch Theory allowed the perfect symmetry between red, green, and blue quarks to be broken; this was normally an extremely fleeting occurrence, but it was possible that interactions between the neutron stars could stabilize it. Quarks of a certain color could become "locally heavier" in one core, causing them to sink slightly until the attraction of the other quarks buoyed them up; in the other core, quarks of the same color would be lighter, and would rise. Tidal and rotational forces would also come into play.

The separation of color would be minute, but the effects would be dramatic: the two orbiting, polarized cores would generate powerful jets of mesons, which would act to brake the neutron stars' orbital motion a kind of nuclear analogue of gravitational radiation, but mediated by the strong force and hence much more energetic. The mesons would decay almost at once into other particles, but this secondary radiation would be very tightly focused, and since the view from the solar system was high above the plane of Lac G-1's orbit the beams would never be seen head-on. No doubt they'd become spectacularly visible once they slammed into the interstellar medium, but after only 16 days they'd still he traveling through the region of relatively high vacuum that the neutron stars had swept clean over the last few billion years.

The whole system would be like a giant Catherine wheel in reverse, with the fireworks pointing backward, opposing their own spin. But as they bled away the angular momentum that kept them apart, gravity would draw them tighter and they'd whip around faster. The nanosecond glitches in the past might have involved small pools of mobile quarks forming briefly, then freezing back into distinct neutrons again, but once the cores melted completely it would be a runaway process: the closer the neutron stars came to each other, the greater their polarization, the stronger the jets, the more rapid their inward spiral.

Karpal knew that the calculations needed to test this idea would be horrendous. Dealing with interactions between the strong force and gravity could bring the most powerful computer to its knees, and any software model accurate enough to he trusted would run far slower than real time, making it useless for predictions. The only way to anticipate the fate of Lac G-1 was to try to see where the data itself was heading.

He had the analysis software fit a smooth curve through the neutron stars' declining angular momentum, and extrapolate it into the future. The fall grew faster, gently at first, but it ended in a steep descent. Karpal felt a cool horror wash through him: if this was the ultimate fate of every binary neutron star, it helped make sense of an ancient puzzle. But it was not good news.

For centuries, astronomers had been observing powerful gamma-ray bursts from distant galaxies. If these bursts were due to colliding neutron stars, as suspected, then just before the collision—when the neutron stars were in their closest, fastest orbits—the gravitational waves produced should have been strong enough for TERAGO to pick up over a range of billions of light years. No such waves had ever been detected.

But now it looked as though Lac G-1's meson jets would succeed in bringing the neutron stars' orbital motion to a dead halt while they were still tens of thousands of kilometers apart. The Catherine wheel's fireworks, having finally triumphed, would sputter out, and the end wouldn't be a frenzied spiral after all, but a calm, graceful dive—generating only a fraction as much gravitational radiation.

Then the two mountain-sized star-heavy nuclei would slam straight together, as if there'd never been a hint of centrifugal force to keep them apart. They'd fall right out of each other's sky—and the heat of the impact would be felt for a thousand light years. Karpal dismissed the image angrily. So far, he had nothing but a three-minute anomaly in an orbital period, and a lot of speculation. What was his judgment worth, after nine years of solitude and far too many cosmic rays? He had to get in touch with colleagues in the asteroid belt, show them the data, and talk through the possibilities calmly.

But if he was right? How long did the fleshers have before Lacerta lit up with gamma rays, six thousand times brighter than the sun?

Karpal checked and re-checked the calculations, fitted curves to different variables, tried every known method of extrapolation.

The answer was the same every time.

Four days.

5

BURSTER

Konishi polis, Earth

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