“The feeling that these failures have been partly, or even mostly, my fault is growing on me,” Cloud thought, tightening his arm a little: and Joan, if anything, yielded to the pressure instead of fighting away from it. “Maybe I haven’t been waiting long enough to give your brains the leeway they need. To check: I’ve been assuming all along that they work in pretty much the same way I do; that they handle all the data, out to the limit of validity of the equations, but aren’t fast enough to work out a three-point-six-second prediction. “But if I’m reading those curves right Margie simply isn’t working that way. She doesn’t seem to be extrapolating _anything_ more than three and a half seconds ahead—’way short of the reliability limit—and sometimes a lot less than that. She isn’t _accepting_ data far enough ahead. She acts as though she can gulp down just so much information without choking on it—so much and no more.” “Exactly. An over-simplification, of course, since it isn’t the kind of choking that giving her a bigger throat would cure, but very well put.” Joan’s right hand crept across her body, rested on Cloud’s wrist, and helped his squeeze, while her face turned more directly toward the face so close to hers. “That’s inherent in the design of all really fast machines . . . and we simply don’t know any way of getting away from it. . . . Why? What has that to do with the case?” “A lot—I hope. When I was working in a flitter I had to wait up to half an hour sometimes, for the sigma curve to stabilize enough so that the equations would hold valid will give a longer valid prediction.” “Stabilize? How? I’ve never seen a sigma curve flatten out. Or does ‘stabilize’ have a special meaning for you vortex experts?” “Could be. It’s what happens when a sigma becomes a little more regular than usual, so that a simpler equation will give a longer valid prediction.” “I see; and a difference in wave-form that would be imperceptible to me might mean a lot to you.” “Right. It just occurred to me that a similar line of reasoning may hold for this seemingly entirely different set of conditions. The less unstable the curve, the less complicated the equations and the smaller the volume of actual data. . . .” “Oh!” Joan’s thought soared high. “So Margie may work _yet_, if we wait a while?” “Check. Browning can’t take the ship away from you, can he?” “No. Nobody can do anything until the job is done or I punch that red ‘stop’ button there. D’you suppose she _can_ do it? Storm? How long can we wait?” “Half an hour, I’d say. No, to settle the point definitely, let’s wait until I can get a full ten-second prediction and see what Margie’s doing about the situation then.” “Wonderful! But in that case, it might be a good idea for you to be looking at the chart, don’t you think?” she asked, pointedly. His eyes, at the moment, were looking directly into hers, from a distance of approximately twelve inches. “I’ll look at it later, but right now I’m. . . .”