"Ended! Great Galaxy, we have only begun. I've got to explain the possibilities of nova formation."
Abel shifted uneasily in his seat. "It is not necessary to do that, Doctor."
"It is very necessary. It is essential. Give me five minutes."
"Let him speak," said Fife. He was smiling.
Junz said, 'Take it from the beginning. In the earliest recorded scientific writings of Galactic civilization it was already known that stars obtained their energy from nuclear transformations in their interiors. It was also known that, given what we know about conditions in stellar interiors, two types, and only two types, of nuclear transformations can possibly yield the necessary energy. Both involve the conversion of hydrogen to helium. The first transformation is direct: two hydrogens and two neutrons combine to form one helium nucleus. The second is indirect, with several steps. It ends up with hydrogen becoming helium, but in the intermediate steps, carbon nuclei take part. These carbon nuclei are not used up but are re-formed as the reactions proceed, so that a triffing amount of carbon can be used over and over again, serving to convert a great deal of hydrogen to helium. - The carbon acts as a catalyst, in other words. All this has been known back to the days of prehistory, back to the time when the human race was restricted to a single planet, if there ever was such a time."
"If we all know it," said Fife, "I would suggest that you are contributing nothing but a waste of time."
"But this is all we know. Whether stars use one or the other, or both, nuclear processes has never been determined. There have always been schools of thought in favor of each of the alternatives. Usually the weight of opinion has been in favor of the direct hydrogen-helium conversion as being the simpler of the two.
"Now Elk's theory must be this. The hydrogen-helium direct conversion is the normal source of stellar energy, but under certain conditions the carbon catalysis adds its weight, hastening the process, speeding it up, heating up the star.
"There are currents in space. You all know that well. Some of these are carbon currents. Stars passing through the currents pick up innumerable atoms. The total mass of atoms attracted, however, is incredibly microscopic in comparison to the star's weight and does not affect it in any way. Except for carbon! A star that passes through a current containing unusual concentrations of carbon becomes unstable. I don't know how many years or centuries or millions of years it takes for the carbon atoms to diffuse into the star's interior, but it probably takes a long time. That means that a carbon current must be wide and a star must intersect it at a small angle. In any case, once the quantity of carbon percolating into the star's interior passes a certain critical amount, the star's radiation is suddenly boosted tremendously. The outer layers give way under an unimaginable explosion and you have a nova.
"Do you see?"
Junz waited.
Fife said, "Have you figured all this out in two minutes as a result of some vague phrase the Townman remembered the Spatb-analyst to have said a year ago?"
"Yes. Yes. There's nothing surprising in that. Spatio-analysis is ready for that theory. If Rik had not come up with it, someone else would have shortly. In fact, similar theories have been advanced before, but they were never taken seriously. They were put forward before the techniques of Spatio-analysis were developed and no one was ever able to account for the sudden acquisition of excess carbon by the star in question.
"But now we know there are carbon currents. We can plot their courses, find out what stars intersected those courses in the past ten thousand years, check that against our records for nova formation and radiation variations. That's what Rik must have done. Those must have been the calculations and observations he tried to show the Townman. But that's all beside the immediate point.
"What must be arranged for now is the immediate beginning of an evacuation of Florina."
"I thought it would come to that," said Fife composedly.
"I'm sorry, Junz," said Abel, "but that's quite impossible."
"Why impossible?"
"When will Florina's sun explode?"
"I don't know. From Elk's anxiety a year ago, I'd say we had little time."
"But you can't set a date?"
"Of course not."
"When will you be able to set a date?"
"There's no way of telling. Even if we get Elk's calculations, it would all have to be rechecked."
"Can you guarantee that the Spatio-analyst's theory will prove to be correct?"
Junz frowned. "I am personally certain of it, but no scientist can guarantee any theory in advance."
"Then it turns out that you want Florina evacuated on mere speculation."
"I think the chance of killing the population of a planet is not one that can be taken."
"If Florina were an ordinary planet I would agree with you. But Florina bears the Galactic supply of kyrt. It can't be done."
Junz said angrily, "Is that the agreement you came to with Fife while I was gone?"
Fife intervened. He said, "Let me explain, Dr. Junz. The government of Sark would never consent to evacuate Florina, even if the I.S.B. claimed it had proof of this nova theory of yours. Trantor cannot force us because while the Galaxy might support a war against Sark for the purpose of maintaining the kyrt trade, it will never support one for the purpose of ending it."
"Exactly," said Abel. "I am afraid our own people would not support us in such a war."
Junz found revulsion growing strong within him. A planet full of people meant nothing against the dictates of economic necessity!
He said, "Listen to me. This is not a matter of one planet, but of a whole Galaxy. There are now twenty full novae originating within the Galaxy every year. In addition, some two thousand stars among the Galaxy's hundred billion shift their radiation characteristics sufficiently to render uninhabitable any habitable planet they may have. Human beings occupy one million stellar systems in the Galaxy. That means that on an average of once every fifty years some inhabited planet somewhere becomes too• hot for life. Such cases are a matter of historical record. Every five thousand years some inhabited planet has a fifty-fifty chance of being puffed to gas by a nova.
"If Trantor does nothing about Florina, if it allows it to vaporire with its people on it, that will serve notice to all the people of the Galaxy that when their own turn comes they may expect no help, if such help is in the way of the economic convenience of a few powerful men. Can you risk that, Abel?
"On the other hand, help Florina and you will have shown that Trantor puts its responsibility to the people of the Galaxy above the maintenance of mere property rights. Trantor will win good will that it could never win by force."
Abel bowed his head. Then he shook it wearily. "No, Junz. What you say appeals to me, but it is not practical. I can't count on emotions as against the assured political effect of any attempt to end the kyrt trade. In fact, I think it might be wise to avoid investigating the theory. The thought that it might be true would do too much harm."
"But what if it is true?"
"We must work on the assumption that it is not. I take it that when you were gone a few moments ago it was to contact the I.S.B."
"Yes."
"No matter. Trantor, I think, will have enough influence to stop their investigations."
"I'm afraid not. Not these investigations. Gentlemen, we will soon have the secret of cheap kyrt. There will be no kyrt monopoly within a year, whether or not there is a nova."
"What do you mean?"
"The conference is reaching the essential point now, Fife. Kyrt grows only on Florina of all inhabited planets. Its seeds produce ordinary cellulose elsewhere. Florina is probably the only inhabited planet, on a chance basis, that is currently pre-nova, and it has probably been pre-nova since it first entered the carbon current, perhaps thousands of years ago, if the angle of intersection was small. It seems quite probable, then, that kyrt and the prenova stage go together."