headache (he really had had too much to drink the previous evening), and set off.
Something about the stars
Clive, the biggest pain in the neck in the astrophysics faculty, was patiently drawing a Hertzsprung-Russell diagram on the board. He could of course simply have called it up on the screen by lightly waving his finger, but no, as Clive liked to put it, food for thought is only digested when it is thoroughly chewed.
Completing the curve of the sub-giants, Clive turned to the class. The first-year students, who were already used to his little ways, were calmly copying the clumsy squiggles scribbled on the board by Clive. Earlier, the most daring of them would try to criticise Clive's methods, but this hubris was soon stilled under the unyielding pressure of the Great Pain in the Neck's logic. The Great Pain in the Neck possessed one very valuable quality: he knew how to explain even the most difficult material in simple language. It was for this reason that the first-course students preferred his lectures to those of the others, and were willing to put up with his grumbling throughout the entire semester. Their reward for this was outstanding knowledge and, as a rule, a good assessment - Clive was a pain in the neck, but he was an honest one, and if a student knew the subject, no power in the Universe could make Clive give him or her a poor assessment.
"So, we can see from the diagram that most stars are in the so-called main sequence. Stars in this category obtain their energy from nuclear synthesis reactions, converting hydrogen to helium. Now a question for the audience. How did the heavier elements form in the Universe?"
A suppressed whispering went round the hall, but no-one was willing to answer. Clive would not have been an outstanding teacher if he had not judged the mood of his audience correctly. The students had lost interest - heavy elements, light elements, who cared?
"As I can see, the importance of this question has not quite been understood."
Clive did not mock their lack of knowledge of such elementary matters; after all, students attended his course to gain that very knowledge.
"Let us turn to the beginning of the Universe. We are on the time axis at the point of zero plus an infinitely small space of time. The Universe has just been created by the Big Bang. What do we see? Nothing. Space is opaque, it is filled with energy, seething with radiation. The monstrous temperature prevents the formation of material. All that exists is energy, compressed into an unimaginably small space to an unimaginably high density. And now the Universe begins to expand." Clive noted with satisfaction that he had recaptured the attention of the hall and was holding it in his firmly clenched hand.
"Let a few instants elapse, allow the Universe to expand, and we find its temperature has fallen to such an extent as the result of its expansion that atoms can form. What is formed first? The simplest elements, naturally - those at the beginning of the periodic table. Hydrogen, my friends, hydrogen! What does a hydrogen atom consist of? This element has the atomic number One, therefore its atom contains only one proton and one electron rotating round it. You couldn't imagine anything simpler. Free protons, scurrying around hither and thither in the Universe, each pick up one electron and form an atom of a certain substance. This process took place an incalculable number of times in the Universe, and as a result, even today, 14 billion years later, the most widespread substance is still this same hydrogen.
"But look at your hand."
The students in the hall obediently began looking at their hands as if they had never seen them before.
"What do you see? You see organic material containing carbon, probably the most important building brick of life. Look at your fingers. Some of you will see rings of precious metals, silver, gold, platinum... Where did these elements come from, if initially there was only hydrogen?
"If we look at the diagram I have drawn, we will see that the majority of stars convert hydrogen to helium by nuclear synthesis. These two elements differ in their atomic numbers - One and Two respectively. As I said earlier, a nuclear synthesis process takes place in the cores of stars, as a result of which a new element is born in the periodic table. This is accompanied by the release of energy, thanks to which we can observe the luminosity of the stars. Sooner or later the time comes when a star has synthesised all the hydrogen in its core and turned it into helium. The hydrogen synthesis process still proceeds at the periphery, and the star enters the next stage of evolution. If the star is heavy enough, the process of transition from the first stage continues until all the material of the star has been transformed into iron. That is how the elements up to iron appear."
At this point, Clive decided that the scientific material had been chewed thoroughly enough. With a wave of his hand, he called up a visualised model of the transformation of a star into a red giant on the big screen in the middle of the hall. Against a black background, a yellow sphere appeared, ejecting impressive splashes of plasma from time to time.
"As we see," Clive continued, "the star is now precisely in the stage of synthesising helium from hydrogen. Now let us see what happens when only iron remains. In stellar terms, iron is nothing other than ash. That which is left when everything is burned up."
Clive gestured to the computer to simulate the process. The yellow star began to grow, and its colour changed to dark red.
"We see that the star has increased in size. The outer layers are beginning to move out from the core" - the red sphere on the screen continued to grow - "and to cool down as a result of their expansion. This explains why the colour changes from bright yellow to dark red. I must add that at this moment, the star is leaving the main sequence curve and passing into the giant category. Back to the outer layers. They are continuing to expand, and as a result, fly off into space and..."
The enormous red sphere grew to an incredible size, then the red shell became transparent, ceased to shine and merged into the vastness of space.
"...the star has thrown off its outer shell, and along with it the elements born within itself. The new elements are scattered in every direction throughout the Universe. Some of them eventually collect into a cloud from which planets subsequently formed. The planets then lay the foundation for biological life. And we, you and I, are no exception either. Our bodies consist of stellar ash, born by a star which exploded billions of years ago somewhere in the depths of the infinite Universe."
Having finished this sentence, Clive fell silent and looked up at the wall clock over the entrance. The second hand had only three divisions to go to the end of the lecture. The bell rang.
"Thank you for your attention. At the next lecture, we shall learn how the rest of the elements appeared. The task for today's theme, as always, can be found on my webpage."
He was impressed but not surprised that he had managed to get through all the planned material in time. Such precision can only be achieved by few, only by those who plan their actions accurately and strictly adhere to their plan. Those like Clive.
Today's studies had ended. With a feeling of deep satisfaction, Clive put his things in his briefcase and left the class.
The evening sun was no longer burning, but just giving a pleasant warmth. The sultry heat of the day had given way to the cool of the evening. Clive enjoyed every moment, walking unhurriedly in the direction of the observatory.
Steve was walking towards him and wasn't keen to stop and talk, but Clive had already noticed him and Steve was reluctant to be seen deliberately to be avoiding a meeting. Yes, Clive was a nerdish sort of chap, but all the same, they were colleagues in their work at the observatory. And they'd been on the same course. And anyway, Clive wasn't that bad, a bit of a nerd, but not a bad guy. When they were level with each other, they stopped.
"Hi, Clive," Steve casually waved his hand in greeting.
"Steve," Clive nodded in reply. "Is anything going on?"
"No, everything's still as it was." Of course, Steve could have told him about the interesting object, but not now. If he said a word about his discovery, Clive would bombard him with questions and add a couple of theori
es too, and he'd never get away.
"You look kind of tired, are you preparing for the seminars?" asked Clive.
"Uh-huh," replied Steve. "Spot on. That's all I'm thinking about."
The thing Steve liked about Clive was that he did not understand irony, and it was very easy to make fun of him. Also, Clive rarely took offence, and if he did, quickly got over it, and although he didn't forget it, he behaved as if nothing had happened.
"I'd better get going. Are you going straight to the observatory?"
"Yes I am, it's my shift. And apart from that, I have to figure something out."
"Oh yes, I saw that - Advanced collision model?"
"That's right! And do you know what I found?" Clive's face stretched into a smile as he prepared to talk to Steve at length.
"Something interesting, no doubt, but you can tell me about it tomorrow. Excuse me, Clive, but my head's bursting at the seams from my own models. Not now."
Steve certainly did not want to listen to Clive's latest theory. He had theories for everything. For example, a crystallisation anomaly theory. Or a theory of condensates. The first explained why ice cubes in Clive's freezer did not form in order, but in some other sequence. The second threw light on why Clive's spectacles always misted up more on the left than on the right when he entered the refrigeration chamber in the biology faculty to pick up his lunch pack. The most nerdish thing in all these flights of fancy was the fact that he backed up his theories with mathematical calculations and checked them experimentally. That was why it was so difficult to argue with him. He always had empirical data obtained strictly according to the rules of science.
"Well, it's up to you." Clive shrugged. "Till tomorrow, then."
Clive went on his way to the observatory, where an extremely interesting evening awaited him, alone with his favourite model. A computer model.
Night
Steve woke up with a start. He opened his eyes. He looked up for a few seconds, then turned his head sharply to the side. He looked round the side of his room, still not understanding where he was. Then he raised himself a little, leaning on his elbow, and looked round the other part of the room. The window was open, letting in the cool, scented night air. A wind was lightly rustling round the room, blowing on one object after another. A book open on the table rustled as it was caught by gusts of wind, the open page turned forward and then unhurriedly back, which was somehow comforting, but also created a barely perceptible feeling of inexplicable anxiety. The room was slightly illuminated by the moon shining through the trees.
Steve's consciousness slowly returned from the world of dreams to the real world. A few minutes previously, Steve had had a very eventful dream. His brain was fully working, but now he couldn't remember even roughly what it had been about. Finally he realised where he was - at home in his room, in his apartment. He was renting it from some guy he had never seen - he had only spoken to him once, on the phone. This guy left the key for Steve in the university front office in a yellow envelope. Steve paid his rent regularly, never raised hell (at least, not at home), and didn't create any problems. The guy never bothered Steve either. He just never appeared at all. At one time, Steve even thought that he could have disappeared somewhere, and he need no longer pay for the apartment. But he decided not to check this theory, and went on paying his rent. Peace and quiet were worth more to Steve than money, more anyway than the money he was paying for what was basically a good apartment at a cheap rent, in a little house near a small lake.
In the evenings, shortly before sunset, when the sun was just disappearing over the horizon, frogs