"So these motes can look right through the rock?"

A.J. laughed. "Not exactly. Let me take a look at what we have and I'll explain a little more."

Helen showed him around the dig area, letting the imaging and sensor expert kneel down to examine the fossils and surrounding rock. She saw him reach into the pouch and then let fall a ghostly shimmer of the dust-mote sensors across the area. From the side, Helen could see that the light behind his glasses was directed into his eye; what she'd seen vaguely before was the reflection. A Virtual Retinal Display, then, rather than a mini heads-up display projection. The VRD flickered brightly from his eye for a moment or two.

"Hmm, interesting." The imaging specialist seemed to have the habit of talking to himself. "Yeah, we can work with that."

He turned back to Jackie. "The motes are really excellent at sensing things, and if I combine the signals from thousands of them across the area, that's great-but only if there's something to sense. And there's no way anything their size can produce the beefy signals I'm going to need. Penetration through rock depends on a lot of different things-the type of signal, the wavelength, the precise type of rock, presence of moisture, and the power available probably being the most dominant, although there's a bunch of other ancillary ones. For the most part, I can control three of those variables-type, wavelength, and power. The trick here is that we have something of a dilemma. We want lots of penetration, but we also want lots of detail. As a rule, penetration increases with increasing wavelength-but the level of detail that can be detected decreases with increasing wavelength. If I want a shorter wavelength to give me a readable return, then I need a lot of power."

Helen nodded along with Jackie, as A.J. continued to carefully sift his Fairy Dust onto the ground in the area of the fossils and the rock still left to be removed.