I prodded him. "Bloom says he thinks such a device can be built."
Priss nodded. "Well, yes, but I wonder. Ed Bloom has had an amazing knack at seeing the unobvious in the past. He has an unusual mind. It’s certainly made him rich enough."
We were sitting in Priss’s apartment. Ordinary middle-class. I couldn’t help a quick glance this way and that. Priss was not wealthy.
I don’t think he read my mind. He saw me look. And I think it was on his mind. He said, "Wealth isn’t the usual reward for the pure scientist. Or even a particularly desirable one."
Maybe so, at that, I thought. Priss certainly had his own kind of reward. He was the third person in history to win two Nobel Prizes, and the first to have both of them in the sciences and both of then unshared. You can’t complain about that. And if he wasn’t rich, neither was he poor.
But he didn’t sound like a contented man. Maybe it wasn’t Bloom’s wealth alone that irked Priss; maybe it was Bloom’s fame among the people of Earth generally; maybe it was the fact that Bloom was a celebrity wherever he went, whereas Priss, outside scientific conventions and faculty clubs, was largely anonymous.
I can’t say how much of all this was in my eyes or in the way I wrinkled the creases in my forehead, but Priss went on to say, "But we’re friends, you know. We play billiards once or twice a week. I beat him regularly." (I never published that statement. I checked it with Bloom, who made a long counterstatement that began "He beats me at billiards. That jackass – " and grew increasingly personal thereafter. As a matter of fact, neither one was a novice at billiards. I watched them play once for a short while, after the statement and counterstatement, and both handled the cue with professional aplomb. What’s more, both played for blood, and there was no friendship in the game that I could see.) I said, "Would you care to predict whether Bloom will manage to build an anti-gravity device?"
"You mean would I commit myself to anything? Hmm. Well, let’s consider, young man. Just what do we mean by anti-gravity? Our conception of gravity is built around Einstein’s General Theory of Relativity, which is now a century and a half old but which, within its limits, remains firm. We can picture it – "
I listened politely. I’d heard Priss on the subject before, but if I was to get anything out of him – which wasn’t certain – I’d have to let him work his way through in his own way.
"We can picture it," he said, "by imagining the Universe to be a Oat, thin, superflexible sheet of untearable rubber. If we picture mass as being associated with weight, as it is on the surface of the Earth, then we would expect a mass, resting upon the rubber sheet, to make an indentation. The greater the mass, the deeper the indentation.
"In the actual Universe," he went on, "all sorts of masses exist, and so our rubber sheet must be pictured as riddled with indentations. Any object rolling along the sheet would dip into and out of the indentations it passed, veering and changing direction as it did so. It is this veer and change of direction that we interpret as demonstrating the existence of a force of gravity. If the moving object comes close enough to the center of the indentation and is moving slowly enough, it gets trapped and whirls round and round that indentation. In the absence of friction, it keeps up that whirl forever. In other words, what Isaac Newton interpreted as a force, Albert Einstein interpreted as geometrical distortion."
He paused at this point. He had been speaking fairly frequently – for him – since he was saying something he had said often before. But now he began to pick his way.
He said, "So in trying to produce anti-gravity, we are trying to alter the geometry of the Universe. If we carry on our metaphor, we are trying to straighten out the indented rubber sheet. We could imagine ourselves getting under the indenting mass and lifting it upward, supporting it so as to prevent it from making an indentation. If we make the rubber sheet Oat in that way, then we create a Universe – or at least a portion of the Universe – in which gravity doesn’t exist. A rolling body would pass the non-indenting mass without altering its direction of travel a bit, and we could interpret this as meaning that the mass was exerting no gravitational force. In order to accomplish this feat, however, we need a mass equivalent to the indenting mass. To produce antigravity on Earth in this way, we would have to make sure of a mass equal to that of Earth and poise it above our heads, so to speak."
I interrupted him. "But your Two-Field Theory – "
"Exactly. General Relativity does not explain both the gravitational field and the electromagnetic field in a single set of equations. Einstein spent half his life searching for that single set – for a Unified Field Theory – and failed. All who followed Einstein also failed. I, however, began with the assumption that there were two fields that could not be unified and followed the consequences, which I can explain, in part, in terms of the ‘rubber sheet’ metaphor."
Now we came to something I wasn’t sure I had ever heard before. "How does that go?" I asked.
"Suppose that, instead of trying to lift the indenting mass, we try to stiffen the sheet itself, make it less indentable. It would contract, at least over a small area, and become flatter. Gravity would weaken, and so would mass, for the two are essentially the same phenomenon in terms of the indented Universe. If we could make the rubber sheet completely flat, both gravity and mass would disappear altogether.
"Under the proper conditions, the electromagnetic field could be made to counter the gravitational field, and serve to stiffen the indented fabric of the Universe. The electromagnetic field is tremendously stronger than the gravitational field, so the former could be made to overcome the latter."
I said uncertainly, "But you say ‘under the proper conditions. ‘ Can those proper conditions you speak of be achieved, Professor?"
"That is what I don’t know," said Priss thoughtfully and slowly. "If the Universe were really a rubber sheet, its stiffness would have to reach an infinite value before it could be expected to remain completely flat under an indenting mass. If that is also so in the real Universe, then an infinitely intense electromagnetic field would be required and that would mean anti-gravity would be impossible."
"But Bloom says – "
"Yes, I imagine Bloom thinks a finite field will do, if it can be properly applied. Still, however ingenious he is," and Priss smiled narrowly, "we needn’t take him to be infallible. His grasp on theory is quite faulty. He – he never earned his college degree, did you know that?"
I was about to say that I knew that. After all, everyone did. But there was a touch of eagerness in Priss’s voice as he said it and I looked up in time to catch animation in his eye, as though he were delighted to spread that piece of news. So I nodded my head as if I were filing it for future reference.
"Then you would say, Professor Priss," I prodded again, "that Bloom is probably wrong and that anti-gravity is impossible?"
And finally Priss nodded and said, "The gravitational field can be weakened, of course, but if by anti-gravity we mean a true zero-gravity field – no gravity at all over a significant volume of space – then I suspect anti-gravity may turn out to be impossible, despite Bloom."
And I had, after a fashion, what I wanted.
I wasn’t able to see Bloom for nearly three months after that, and when I did see him he was in an angry mood.
He had grown angry at once, of course, when the news first broke concerning Priss’s statement. He let it be known that Priss would be invited to the eventual display of the antigravity device as soon as it was constructed, and would even be asked to participate in the demonstration. Some reporter – not I, unfortunately – caught him between appointments and asked him to elaborate on that and he said: