Timothy was now a little puzzled. The boy would have had to read quite a bit to find that, and having done so, to actually go into town and find some amber and fur would have taken effort. The boy seemed to find things interesting. Whether that was good or bad remained to be seen. In the meantime, he had to keep going. "Let's move on to Anaximander, also of Miletus. Anaximander believed that the original substance of the universe was formless and from this, everything was created. The uneven creation led to forces, and these forces have formed the present and will form the future. Every force has a contrary, thus hot counters cold, wet counters dry, and so on. Every motion in the Universe is a result of such forces, and most things are acted upon by forces and therefore change. Your comments?"
"Forces drive change, but maybe we shouldn't invent forces simply because something changes. What I mean is, if there's a net force there will be a change, but it doesn't follow that there is a force behind every change."
"That's a good point of logic," Timothy smiled. "Suppose I say, all cows eat grass. That is a one-way statement, hence if I see a cow I know it eats grass, but if someone tells me there is something eating grass, it doesn't have to be a cow. Now, back to the concept of forces and contraries. Anything else?"
"If the forces tend to bring everything together, then surely soon everything will be thoroughly mixed?"
"Good! But you see, there is inherent unevenness. The sun only shines in the day, therefore the heat of the sun is uneven, so while the forces attempt to bring everything together, there are also causes of separation. Anaximander decided that while the contrary forces were universal and were trying to bring the Universe into harmony, there are also changes and situations that increase the separation. Give another example in which the separation of contraries is maintained, and explain why?"
"I can't. ." Gaius shrugged. "I don't know. ."
"You can't! How useful!" Timothy scowled. He had to try to irritate his young charge, because he had to know whether he had potential, or whether this was simply an exercise he had to go through. On the other hand, he must not irritate too much. "Take your time! Think!" Timothy gave a quiet smile, and sat back and began munching a piece of bread and cheese. As tests went, this could be even more useful.
At first nothing came to Gaius, however it seemed that the answer was presumably related to this Greek physics. He should review all he knew, which would not take long. He was almost going to give up, when a thought struck him. "I may have something," he announced.
"May? As Aristotle would have noted, you either have or have not. Which is it?"
"How about this?" Gaius asked. He suddenly felt confident. "As I recall from Aristarchus, the sun is a long way away, and it shines heat. The Earth is a ball, so where the heat strikes square-on, such as to the south of us, it gets very hot, while at the north, it stays dark throughout the winter and it gets very cold. These so-called contraries are being generated continually."
"And the forces of cold and the heat generate storms in the middle," Timothy nodded. Now was the time to be mildly encouraging. Possibly this was a lucky guess, and it was a pity he had to fix on that heretic, but on the other hand here was something quite unusuaclass="underline" a Roman sufficiently interested in Greek science to actually read it. There was also a practical reason: there was no point in pushing this young man into violence. "But there's more. Rain may wash away the side of a hill but nothing builds it up. Everything is gradually changing, and can never go back to the beginning. Even life is changing."
"It is?"
"It is. Think! Give me an example."
"I didn't even know it was," Gaius grumbled. "How can I be expected to. ."
"An enemy army appears on your left flank and you didn't even know it was there," Timothy said harshly. "What do you do? Bleat?"
"That's not. ." Gaius suddenly paused, then grinned. "Yes, I can think of a change. Sheep. Wild sheep do not have wool, but rather they have hair!"
"Strictly speaking," Timothy said, "that's not quite true, but it's an example. Find out what you can about sheep. Don't tell me, just work it out for yourself. Sooner or later you will have to use that knowledge, but I'm not going to tell you when. Now, the most important contribution from Anaximander was contraries. Go, read up what you can about contraries. I want you to think generally, but also concentrate on locomotion." Gaius nodded, and as he left the room, Timothy mumbled to himself, "That should give him something to do for a while."
* * *
Gaius also had occasional sessions with the Greek Geminus, who was also somewhat intrigued by a Roman who wished to be a soldier and who seemed interested in Aristarchus. At first, Geminus announced that he would only teach if Gaius successfully showed aptitude and interest, and immediately began discussing what a hypothesis, a postulate, and a theorem were, then what a line was, a surface, and so on. Then he gave Gaius some observational data on planetary motion and asked him to formulate an explanation in terms of Aristarchus' hypothesis. Gaius began to find his days were filling.
It took more than a week looking at pages and pages of data before he was ready to make calculations, then he used a surprising amount of papyrus to record the calculations he made on wax tablets, and with string and markings on a large floor, but eventually he was able to return to Geminus and inform him that he had something: the paths of the planets were consistent with the Aristarchus model, and the reason they turned around and went backwards was because the Earth was travelling inside their orbits, and passed them. He showed Geminus how he had worked out how the data showed how long each planet took to go around the sun, and from their observed paths, he made an estimate of their distances relative to the Earth-Sun distance.
"The distance estimates are a bit rough," Gaius admitted. "I took observations from the retrograde motion, predicted the background of the planet from that point on the Earth's orbit, and selected data from where it actually was later. I know how long each planet takes to return to the same position, but I am not sure that the observed angles are very good, because that wasn't why they were measured. The distances are very large, so maybe they're wrong."
"Very good," Geminus nodded, after he checked what Gaius had done. "If you believe Aristarchus, your geometry seems to be correct, even if the data are wrong. Anything else?"
"Yes," Gaius nodded, "at least I think so. If we look at how far Mars is, and how much it dims, then consider how bright Jupiter and Saturn are, they must be huge if they shine by reflected light. And one last thing: if the stars are suns, as many suspect, then they must be very far away, and not only that, because they have different brightness, they can't all be the same distance. Putting them all on one sphere would be wrong."
If nothing else, this pleased Geminus, for he had advocated this same point. What surprised him was that Gaius had heard of it. As it happened, Gaius had not heard of Geminus' propositions, but his statement had had an effect: he would learn more mathematics. While he felt that, to some extent, this was something he simply had to put up with, nevertheless a time would come when this would save his life.
* * *
Timothy had no clear expectation. He had set Gaius off on this intellectual expedition partly to test the young man, but also to get more time to himself. For a week he was quite pleased. Gaius had not come running back, bleating that he could not do anything, and he had enjoyed his spare time. After two weeks he was beginning to think Gaius had given up, and with time this feeling grew. At first Timothy had pleasant dreams of freedom, for he was sure young Scaevola would be too ashamed not to keep his word. Then there were moments approaching despair, for he suddenly began to realize that he had no idea how he could earn a living commensurate with the lifestyle he had adopted. So far he could buy what he wanted because the bills had gone to Tiberius, and Tiberius had seemingly not bothered to question them. Then his dreams and concerns were burst when, after four weeks, Gaius appeared.