The audience must have been listening with considerable astonishment for there is no record of interruption, at least until the sentence last recorded above, at which time Hallam seemed to have paused to catch his breath and perhaps to wonder at his own temerity.

Someone from the audience (presumably Antoine-Jerome Lapin, though the record is not clear) asked if Professor Hallam were suggesting that an intelligent agent in the para-Universe had deliberately made the exchange in order to obtain an energy source. The expression “para-Universe,” inspired apparently as an abbreviation of “parallel-Universe,” thus entered the language. This question contained the first recorded use of the expression.

There was a pause and then Hallam, more daring than ever, said—and this was the nub of the Great Insight — “Yes, I think so, and I think that the energy source cannot be made practical unless Universe and para-Universe work together, each at one half of a pump, pushing energy from them to us and from us to them, taking advantage of the difference in the natural laws of the two Universes.”

Hallam had adopted the word “para-Universe” and made it his own at this point. Furthermore, he became the first to use the word “pump” (since invariably capitalized) in connection with the matter.

There is a tendency in the official account to give the impression that Hallam’s suggestion caught fire at once, but it did not. Those who were willing to discuss it at all would commit themselves no farther than to say it was an amusing speculation. Kantrowitsch, in particular, did not say a word. This was crucial to Hallam’s career.

Hallam could scarcely carry through the theoretical and practical implications of his own suggestion all by himself. A team was required and it was built up. But none of the team, until it was too late, would associate himself openly with the suggestion. By the time success was unmistakable, the public had grown to think of it as Hallam’s and Hallam’s alone. It was Hallam, to all the world, and Hallam alone, who had first discovered the substance, who had conceived and transmitted the Great Insight; and it was therefore Hallam who was the Father of the Electron Pump.

Thus, in various laboratories, pellets of tungsten metal were laid out temptingly. In one out of ten the transfer was made and new supplies of plutonium-186 were produced. Other elements were offered as bait and refused.... But wherever the plutonium-186 appeared and whoever it was that brought the supply to the central research organization working on the problem, to the public it was an additional quantity of “Hallam’s-tungsten.”

It was Hallam again who presented some aspects of the theory to the public most successfully. To his own surprise (as he later said) he found himself to be a facile writer, and he enjoyed popularizing. Besides success has its own inertia, and the public would accept information on the project from no one but Hallam.

In a since famous article in the North American Sunday Tele-Times Weekly, he wrote, “We cannot say in how many different ways the laws of the para-Universe differ from our own, but we can guess with some assurance that the strong nuclear interaction, which is the strongest known force in our Universe, is even stronger in the para-Universe; perhaps a hundred times stronger. This means that protons are more easily held together against their own electrostatic attraction and that a nucleus requires fewer neutrons to produce stability.

“Plutonium-186, stable in their Universe, contains far too many protons, or too few neutrons, to be stable in ours with its less effective nuclear interaction. The plutonium-186, once in our Universe, begins to radiate positrons, releasing energy as it does so, and with each positron emitted, a proton within a nucleus is converted to a neutron. Eventually, twenty protons per nucleus have been converted to neutrons and plutonium-186 has become tungsten-186, which is stable by the laws of our own Universe. In the process, twenty positrons per nucleus have been eliminated. These meet, combine with, and annihilate twenty electrons, releasing further energy, so that for every plutonium-186 nucleus sent to us, our Universe ends up with twenty fewer electrons.

“Meanwhile, the tungsten-186 that enters the para-Universe is unstable there for the opposite reason. By the laws of the para-Universe it has too many neutrons, or too few protons. The tungsten-186 nuclei begin to emit electrons, releasing energy steadily while doing so, and with each emitted electron a neutron changes to a proton until, in the end, it is plutonium-186 again. With each tungsten-186 nucleus sent into the para-Universe, twenty more electrons are added to it.

“The plutonium/tungsten can make its cycle endlessly back and forth between Universe and para-Universe, yielding energy first in one and then in another, with the net effect being a transfer of twenty electrons from our Universe to their per each nucleus cycled. Both sides can gain energy from what is, in effect, an Inter-Universe Electron Pump.”

The conversion of this notion into reality and the actual establishment of the Electron Pump as an effective energy source proceeded with amazing speed, and every stage of its success enhanced Hallam’s prestige.

Lament had no reason to doubt the basis of that prestige and it was with a certain hero-worshipfulness (the memory of which embarrassed him later and which he strove—with some success—to eliminate from his mind) that he first applied for a chance to interview Hallam at some length in connection with the history he was planning.

Hallam seemed amenable. In thirty years, his position in public esteem had become so lofty one might wonder why his nose did not bleed. Physically, he had aged impressively, if not gracefully. There was a ponderousness to his body that gave him the appearance of circumstantial weightiness and if his face were gross in its features he seemed able to give them the air of a kind of intellectual repose. He still reddened quickly and the easily bruised nature of his self-esteem was a byword.

Hallam had undergone some quick briefing before Lamont’s entrance. He said, “You are Dr. Peter Lamont and you’ve done good work, I’m told, on para-theory. I recall your paper. On para-fusion, wasn’t it?”

“Yes, sir.”

“Well, refresh my memory. Tell me about it. Informally, of course, as though you were talking to a layman. After all,” and he chuckled here, “in a way, I am a layman. I’m just a radiochemist, you know; and no great theoretician, unless you want to count a few concepts now and then.”

Lament accepted this, at the time, as a straightforward statement, and, indeed, the speech may not have been as obscenely condescending as he later insisted on remembering it to have been. It was typical, though, as Lament later found out, or at least maintained, of Hallam’s method of grasping the essentials of the work done by others. He could talk briskly about the subject thereafter without being overparticular, or particular at all, in assigning credit.

But the younger Lament of the time was rather flattered, and he began at once with that voluble eagerness one experiences in explaining one’s own discoveries. “I can’t say I did much, Dr. Hallam. Deducing the laws of nature of the para-Universe—the para-laws—is a tricky business. We have so little to go on. I started from what little we know and assumed no new departures that we had no evidence for. With a stronger nuclear interaction, it seems obvious that the fusion of small nuclei would take place more readily.”

“Para-fusion,” said Hallam.

“Yes, sir. The trick was simply to work out what the details might be. The mathematics involved was somewhat subtle but once a few transformations were made, the difficulties tended to melt away. It turns out, for instance, that lithium hydride can be made to undergo catastrophic fusion at temperatures four orders of magnitude lower there than here. It takes fission-bomb temperatures to explode lithium hydride here, but a mere dyamite charge, so to speak, would turn the trick in the para-Universe. Just possibly lithium hydride in the para-Universe could be ignited with a match, but that’s not very likely. We’ve offered them lithium hydride, you know, since fusion power might be natural for them, but they won’t touch it.”