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Eden Rescue--chapter 36

August 11, 2014
Posted at 2:00 pm

Somebody e-mailed me a while back to say I was putting too much emphasis on their being able to leave the Eden system before the nova's radiation struck. It would be possible, he said, for them to ride out the radiation storm in the umbra (shadow) of Eden's sun, or even the planet itself.
There'll be a fuller explanation of what just happened in the next chapter. Suffice it to say, neither body would offer a full shield. Consider putting your hand between a light source and a nearby surface. Hold your hand close to the light source, there's a perfect shadow; but move it away from the light the shadow becomes less distinct. Of course ordinary light spreads more rapidly and more broadly than does the kind of collimated beam I'm postulating as emanating from the nova, but even so. And the particles with which the Ark must be concerned are less ephemeral than insubstantive photons. In other words there's bound to be some spread that will soon penetrate the umbra; the shelter it offers will at best be transitory. If they could hang in there within a short distance of the shielding body it might work, but they of course can't. And even then it's uncertain.
Of course, I'm dealing here with speculation, inasmuch as there's obviously no experimental data. Still, consider what we know of lasers. For a short distance the projected beam is remarkable coherent. There have been reports of miscreants using laser pointers to disrupt the vision of aircraft on final landing approach, shining them into the cockpits to blind pilots. But the distance there is no more than a few hundred meters. Over a matter of a kilometer or more the light becomes too attenuated. Same principle, especially since we're considering distances of more than 100 light-years from the nova itself-the source-to Eden.