"Might be interesting. Unmanned vehicle. Worthless target. A small asteroid. A baby sun?"

"I don't know, Zeb. Nor do I have apparatus to spare. It took me three years to build this one."

"So we wait a few years. Jake? Air has mass."

"That worried me also. But any mass, other than degenerate mass, is mostly

empty space. Air-Earth sea-level air-has about a thousandth the density of the human body. The body is mostly water and water accepts air readily. I can't say that it has no effect-twice I've thought that my temperature went up a trifle at transition or translation in atmosphere but it could have been excitement. I've never experienced caisson disease from it. Has any of us felt discomfort?"

"Not me, Jake."

"I've felt all right, Pop," I agreed.

"I got space sick. Till Deety cured it," Aunt Hilda added.

"So did I, my darling. But that was into vacuo and could not involve the phenomenon."

"Pop," I said earnestly, 'we weren't hurt; we don't have to know why. A basic proposition of epistemology, bedrock both for the three basic statements of semantics and for information theory, is that an observed fact requires no proof. It simply is, self-demonstrating. Let philosophers worry about it; they haven't anything better to do."

"Suits me!" agreed Hilda. "You big brains had Sharpie panting. I thought we were going to take a walk?"

"We are, dear," agreed my husband. "Right after those steaks."

"-the whole world is alive."

Zebadiah:

Four Dagwoods later we were ready to start walkabout. Deety delayed by wanting to repeat her test by remote control. I put my foot down. "No!"

"Why not, my Captain? I've taught Gay a program to take her straight up ten klicks. It's G, A, Y, B, 0, U, N, C, ~-a new fast-escape with no execution word necessary. Then I'll recall her by B, U, G, 0, U, T. If one works via walkytalky, so will the second. It can save our lives, it can!"

"Uh-" I went on folding tarps and stowing my sleeping bag. The female

mind is too fast for me. I often can reach the same conclusion; a woman gets there first and never by the route I have to follow. Besides that, Deety is a genius.

"You were saying, my Captain?"

"I was thinking. Deety, do it with me aboard. I won't touch the controls. Check pilot, nothing more."

"Then it won't be a test."

"Yes, it will. I promise, Cub Scout honor, to let it fall sixty seconds. Or to three klicks H-above-G, whichever comes first."

"These walky-talkies have more range than ten kilometers even between themselves. Gay's reception is much better."

"Deety, you trust machinery; I don't. If Gay doesn't pick up your second command-sun spots, interference, open circuit, anything-I'll keep her from crashing."

"But if something else goes wrong and you did crash, I would have killed you!" She started to cry.

So we compromised. Her way. The exact test she had originally proposed.

I wasted juice by roading Gay Deceiver a hundred meters, got out, and we all backed off. Deety said into her walky-talky, "Gay Deceiver... Bug Out!"

It's more startling to watch than it is to be inside. There was Gay Deceiver off to our right, then she was off to our left. No noise-not even an implosion splat! Magic.

"Well, Deety? Are you satisfied?"

"Yes, Zebadiah. Thank you, darling. But it had to be a real test. You see that-don't you?"

I agreed, while harboring a suspicion that my test had been more stringent. "Deety, could you reverse that? Go somewhere else and tell Gay to come to you?"

"Somewhere she's never been?"

"Yes."

Deety switched off her walky-talky and made sure that mine was off. "I don't want her to hear this. Zebadiah, I always feel animistic about a computer. The Pathetic Fallacy-I know. But Gay is a person to me."

Deety sighed. "I know it's a machine. It doesn't have ears; it can't see; it doesn't have a concept of space-time. What it can do is manipulate circuitry in complex ways-complexities limited by its grammar and vocabulary. But those limits are exact. If I don't stay precisely with its grammar and vocabulary, it reports 'Null program.' I can tell it anything by radio that I can tell it by voice inside the cabin-and so can you. But I can't tell it to come look for me in a meadow beyond a canyon about twelve or thirteen klicks approximately southwest of here-now. That's a null program-five undefined terms."

"Because you made it null. You fed 'garbage in' and expect me to be surprised at 'garbage out'-when you did it a-purpose."

"I did not either, I didn't!"

I kissed the end of her nose. "Deety darling, you should trust your instincts. Here's one way to tell Gay to do that without defining even one new term into her vocabulary. Tell her to expect a three-part program. First part: bounce one minimum, ten klicks. Second part: transit twelve point five klicks true course two-two-five. Third part: drop to one klick H-over-G and hover. At that point, if what you described as your location is roughly correct, you will see her and can coach her to a landing without using Jake's twister."

"Uh... twelve and a half kilometers can't be done in units often kilometers. Powered flight?"

"Waste juice? Hon, you just flunked high school geometry. Using Euclid's tools, compass and straight edge, lay out that course and distance, then lay out how to get there in ten-klick units-no fractions."

My wife stared. Then her eyes cleared. "Transit one minimum true course one-seven-three and two thirds, then transit one minimum true course twoseven-six and one third. The mirror image solution uses the same courses in reverse. Plus endless trivial solutions using more than two minima."

"Go to the head of the class. If you don't spot her, have her do a retreating search curve-in her perms, in an Aussie accent. Honey girl, did you actually do that Euclid style?"

"I approximated it Euclid style-but you didn't supply compass and straight edge! Scribe circle radius twelve point five. Bisect circle horizontally by straight edge through origin; quarter it by dropping a vertical. Bisect lower left quadrant-that gives true course two-two-five or southwest. Then set compass at ten units and scribe arcs from origin and from southwest point of circle; the intersections give courses and vertices for both major roots to the accuracy of your straight edge and compass. But simply to visualize that construction-well, I got visualized angles of two-seven-five and one-seven-five. Pretty sloppy.

"So I did it accurately by Pythagorean proposition by splitting the isosceles triangle into two right triangles. Hypotenuse is ten, one side is six and a quarter-and that gives the missing side as seven point eight-zero-six-twofour-seven plus-which gives you one course and you read off the other by the scandalous Fifth Axiom. But I did check by trig. Arc sine point seven-eightzero-six-two-four-seven----"

"Hold it! I believe you. What other ways can you program Gay to find you, using her present vocabulary?"

"Uh....urn juice?"

"If necessary."

"I would have her bounce a minimum, then maximize my signal. Home on me."

"Certainly. Now do the same thing without using juice. Just Jake's twister."

Deety looked thoughtful and about twelve years old, then suddenly said, "Drunkard's Walk'!"-added at once, "But I would place a locus around the Walk just large enough to be certain that I'm inside it. Gay should plot signal level at each vertex. Such a plot would pinpoint the signal source."

"Which way is faster? Home straight in under power? Or Drunkard's Walk?" Deety answered, "Why, the-"-looked startled. "Those are solid-state relays."