James Blish - Cities in Flight

Looking back on it in the dream, he did not understand why he had volunteered. It had simply seemed expected of him, and he had not been able to help it, even though he had known to begin with what it would be like. He belonged on the Bridge, though he hated it—he had been doomed to go there from the first.

And there was … something wrong … with the antigravity. The high brass had asked for its volunteers before the research work had been completed. The present antigravity fields were weak, and there was some basic flaw in the theory. Generators broke down after only short periods of use; burned out, unpredictably, sometimes only moments after having passed their production tests with perfect scores. In waking life, vacuum tubes behaved in that unpredictable way; there were no vacuum tubes anywhere on Jupiter, but machines on Jupiter burned out all the same, burned out at temperatures which would freeze Helmuth solid in an instant.

That was what Helmuth’s antigravity set was about to do. He crouched inside his personal womb, above the boiling sea, the clouds raging by him in little scouring crystals which wore at the chorion protecting him, lit by a plume of hydrogen flame—and waited to feel his weight suddenly become three times greater than normal, the pressure on his body go from sixteen pounds per square inch to fifteen million, the air around him take on the searing stink of poisons, the whole of Jupiter come pressing its burden upon him.

He knew what would happen to him then.

It happened.

Helmuth greeted “morning” on Jupiter V with his customary scream.

Dear Seppi,

Lord knows I have better sense than to mail this, send it to you by messenger, or leave it anywhere in the files—or indeed on the premises—of the Joint Committee; but if one is sensible about such matters these days, one never puts anything on paper at all, and then burns the carbons. As a bad compromise, I am filing this among my personal papers, where it will be found, opened and sent to you only after I will be beyond reprisals.

That’s not meant to sound as ominous as, upon rereading, I see it does. By the time you have this letter, abundant details of what I’ve been up to should be available to you, not only through the usual press garble, but through verbatim testimony. You will have worked out, by now, a rational explanation of my conduct since my re-election (and before it, for that matter). At the very least, I hope you now know why I authorized such a monstrosity as the Bridge, even against your very good advice.

All that is water over the dam (or ether over the Bridge, if you boys are following Dirac’s lead back to the ether these days. How do I know about that? You’ll see in a moment.). I don’t mean to rehash it here. What I want to do in this letter is to leave you a more specialized memo, telling you in detail just how well the research system you suggested to me worked out for us.

Despite my surface appearance of ignoring that advice, we were following your suggestion, and very closely. I took a particular interest in your hunch that there might be “crackpot” ideas on gravity which needed investigation. Frankly, I had no hope of finding anything, but that would have left me no worse off than I had been before I talked to you. And actually it wasn’t very long before my research chief came up with the Locke Derivation.

The research papers which finally emerged from this particular investigation are still in the Graveyard file, and I have no hope that they’ll be released to non-government physicists within the forseeable future. If you don’t get the story from me, you’ll never get it from anyone; and I’ve enough on my conscience now to be indifferent to a small crime like breaking Security. Besides, as usual, this particular “secret” has been available for the taking for years. A man named Schuster—you may know more about him than I do—wondered out loud about it as far back as 1891, before anybody had thought of trying to keep scientific matters a secret. He wanted to know whether or not every large rotating mass, like the Sun for instance, was a natural magnet. (That was before the sun’s magnetic field had been discovered, too. ) And by the 1940’s it was clearly established for small rotating bodies like electrons—a thing called the Lande factor with which I’m sure you’re familiar. I myself don’t understand Word One of it. (Dirac was associated with much of that part of the work. ) Finally, a man named W. H. Babcock of Mount Wilson, pointed out in the 1940’s that the Lande factor for the Earth, the Sun, and a star named 78 Virginius was identical, or damned close to it.

Now all this seemed to me to have nothing to do at all with gravity, and I said so to my team chief, who brought the thing to my attention. But I was wrong (I suppose you’re already ahead of me by now). Another man, Prof. P. M. S. Blackett, whose name was even familiar to me, had pointed out the relationship. Suppose, Blackett said (I am copying from my notes now), we let Pbe magnetic moment, or what I have to think of as the leverage effect of a magnet—the product of the strength of the charge times the distance between the poles. Let U be angular momentum—rotation to a slob like me; angular speed times moment of inertia to you. Then if C is the velocity of light, and G is the acceleration of gravity ( and they always are in equations like this, I’m told), then:

(B is supposed to be a constant amounting to about 0.25. Don’t ask me why. ) Admittedly this was all speculative; there would be no way to test it, except on another planet with a stronger magnetic field than Earth’s—preferably about a hundred times as strong. The closest we could come to that would be Jupiter, where the speed of rotation is about 25,000 miles an hour at the equator—and that was obviously out of the question.

Or was it? I confess that I never thought of using Jupiter, except in wish-fulfillment daydreams, until this matter of the Locke Derivation came up. It seems that by a simple algebraic manipulation, you can stick G on one side of the equation, and all the other terms on the other, and come up with this:

To test that, you need a gravitational field little more than twice the strength of Earth’s. And there, of course, is Jupiter again. None of my experts would give the notion a nickel—they said, among other things, that nobody even knew who Locke was, which is true, and that his algebraic trick wouldn’t stand up under dimensional analysis, which turned out to be true—but irrelevant. (We did have to monkey with it a little after the experimental results were in. ) What counted was that we could make a practical use of this relationship.

Once we tried that, I should add, we were astonished at the accompanying effects: the abolition of the Lorentz-Fitzgerald relationship inside the field, the intolerance of the field itself to matter outside its influence, and so on; not only at their occurring at all—the formula doesn’t predict them—but at their order of magnitude. I’m told that when this thing gets out, dimensional analysis isn’t the only scholium that’s going to have to be revamped. It’s going to be the greatest headache for physicists since the Einstein theory; I don’t know whether you’ll relish this premonitory twinge or not.