she came up to me, but not in her mind. She wanted to get her hands On the machine intelligences in Heechee Heaven, I would judge, at least as much as I wanted to get mine on her. In a 100-minute Earth orbit the transmission time isn’t bad, anyway. As soon as we were in range the machine Albert had programmed for me was talking to him, pumping everything it had learned into him, and by the time I was ready to talk to him he was ready to talk back.
Of course it wasn’t the same. Albert in full three-dimensional color in the tank at home was a lot more fun to chat with than black-and-white Albert on a flat plate in Heechee Heaven. But until some new equipment came up from Earth that was all I had, and anyway it was the same Albert. “Good to see you again, Robin,” he said benevolently, poking the stem of his pipe toward me. “I guess you know you have about a million messages waiting for you?”
“They’ll wait.” Anyway, I had already had about a million, or it seemed that way. What they mostly said was that everybody was annoyed but, in the long run, delighted; and I was once again very rich. “What I want to hear first,” I said, “is what you want to tell me.”
“Sure thing, Robin.” He tapped out his pipe, regarding me. “Well,” he said, “technology first. We know the general theory of the Heechee drive, and we’re getting a handle on the faster-than-light radio. As to the information-handling circuits in the Dead Men and so on-as I am sure you know,” he twinkled, “Cospozha Lavorovna-Broadhead is on her way to join you. I think we may confidently expect considerable progress there, very quickly. In a few days a volunteer crew will go to the Food Factory. We are pretty sure it, too, can be controlled, and if so it will be brought into some nearby orbit for study and, I think I can promise, duplication. I don’t suppose you want to hear about minor technology in detail just now?”
“Not really,” I said. “Or not right at this minute.”
“Then,” he said, nodding as he filled the pipe again, “let me get to some theoretical considerations. First there is the question of black holes. We have unequivocally located the one your friend, Gelle-Klara Moynlin, is in. I believe it would be possible to send a ship there with reasonable assurance that it would arrive without serious damage. Return, however, is another question. There appears to be nothing in the Heechee stores that gives us a cookbook recipe for getting anything out of a black hole. Theory, yes. But if one should desire to convert the theory into practice that will require R&D. A lot of it. I would hesitate to promise results in less than, say, a matter of years. More likely decades. I know,” he said, leaning forward earnestly, “that this is a matter of personal importance to you, Robin. It also may be a matter of grave importance to all of us, by which I mean not only the human race but machine intelligences as well.” I had never seen him look so serious. “You see,” he said, “the destination of the artifact, Heechee Heaven, has also been unequivocally identified. May I show you a picture?”
That was rhetoric, of course. I didn’t reply, and he didn’t wait. He shrank down into a corner of the flatplate screen while the main picture appeared. It was a wash of white, shaped like a very amateurishly drawn Turkish crescent. It was not symmetrical. The crescent was off to one side, and the rest of the picture was black except for an irregular sprinkle of light that completed the horns of the crescent and protracted them into a hazy ellipse.
“It is too bad you cannot see this in color, Robin,” said Albert, squinting up from his corner of the screen. “It is blue rather than white. Shall I tell you what you are seeing? It is orbiting matter around some very large object. The matter to your left, which is coming toward us, travels fast enough to emit light. The matter to the right, which is going away, travels more slowly relative to us. What we are seeing is matter turning into radiation as it is drawn into an extremely large black hole, which is located at the center of our Galaxy.”
“I thought the speed of light was not relative!” I snapped.
He expanded to fill the screen again. “It is not, Robin, but the orbit velocity of the matter which produces it is. That picture is from the Gateway file, and until just recently it was not located in space. But now it is clear that it is at, indeed that in a sense it forms, the galactic core.”
He paused while he lit his pipe, looking at me steadily. Well, that’s not quite true. There was the split-second lag, and even Albert’s circuits couldn’t do anything about it; if I moved his gaze lingered where I had been for just long enough to be disconcerting. I didn’t rush him, and when he had finished puffing the pipe alight he said:
“Robin, I am often unsure of what information to volunteer to you. If you ask me a question, that’s different. About any subject you suggest, I will tell you as much of what I know as you will listen to. I will also tell you what may be so, if you ask for a hypothesis; and I will volunteer hypotheses when, according to the constraints written into my program, that seems appropriate. Gospozha Lavorovna-Broadhead has written quite complex normative instructions for this sort of decision-making, but, to simplify, they come down to an equation. Let V represent the ‘value’ of a hypothesis. Let P represent its probability of being true. If I can complete the sum of VP so that it equals at least one, then I should, and do, volunteer the hypothesis. But, oh, Robin, how hard it is to assign the correct numerical values to P and V/In the specific case now at issue I cannot be in any way sure of any value I can give its probability. But its importance is very high. To all intents, it might as well be regarded as infinite.”
By then he had me sweating. What I know for sure about Albert’s programming is that the longer he takes to tell me something, the less he thinks I am going to like hearing it. “Albert,” I said, “get the hell on with it.”
“Sure thing, Robin,” he said, nodding, but unwilling to be rushed, “but let me first say that this conjecture satisfies not only known astrophysics, although on a rather complex level, but also some other questions, e.g., where Heechee Heaven was going when you turned it around and why the Heechee themselves disappeared. Before I can give you the conjecture I must review four main points, as follows.
“One. The quantities Tiny Jim referred to as ‘gosh numbers’. These are numerical quantities, mostly of the sort called ‘dimensionless’ because they are the same in any units you measure. The mass ratio between the electron and the proton. The Dirac number to express the difference between electromagnetic and gravitational force. The Eddington fine-structure constant. And so forth. We know these numbers to great precision. What we do not know is why they are what they are. Why shouldn’t the fine-structure constant be, say, 150 instead of 137-plus? If we understood astrophysics-if we had a complete theory-we should be able to deduce these numbers from the theory. We do have a good theory, but we can’t deduce the gosh numbers from it. Why? Is it possible,” he asked gravely, “that these numbers are in some way accidental?”
He paused, puffing on his pipe, and then held up two fingers. “Two. Mach’s Principle. This also turns Out to be a question, but perhaps a somewhat easier one. My late predecessor,” he said, twinkling a little-I think to reassure me that this was, indeed, easier to handle-“my late predecessor gave us the theory of relativity, which is commonly understood to mean that everything is relative to something else excepting only the velocity of light. When you are at home on Tappan Sea, Robin, you weigh about eighty-five kilograms. That is to say, that is a measure of how much you and the planet Earth attract each other; it is your weight, in a sense, relative to the Earth. We also have a quality called ‘mass’. The best measure of ‘mass’ is the force necessary to accelerate an object, say you, from a state of rest. We usually consider ‘mass’ and ‘weight’ to be about the same, and on the surface of the Earth they are, but mass is supposed to be an intrinsic quality of matter, while weight is always relative to something else. But,” he twinkled again, “let’s do a gedanke-experiment, Robin. Let’s suppose that you’re the only thing in the universe. There’s no other matter. What would you weigh? Nothing. What would your mass be? Ah, that’s the question. Let’s suppose you have a little rocket-belt and you decided to accelerate yourself. You then measure the acceleration and compute the force to move you, and you come out with your mass-do you? No, Robin, you do not. Because there is nothing to measure movement against! ‘Moving’, as a concept, is meaningless. So mass itself-
