When I started writing Before Eureka! The Adventures of Young Archimedes I thought I would begin with some very easy mathematics. The Greek numeration system had no symbol greater than the one for 10,000, which they called a myriad, but Archimedes needed much larger numbers, so he invented a system for writing them. My idea was to have the young boy think about the number of stars and, although there are only about 6,000 stars visible to the naked eye, recognize a need for representing numbers greater than a myriad. We know from one sentence in Archimedes’ writings that his father, Phidias, was an astronomer, so in the first scene I wrote for the book Phidias is instructing his son about the constellations. As a bonus, I knew that the Greek goddess Artemis was said to have created Orion and Scorpio by flinging Earth creatures into the sky; I had already chosen Artemis as a supernatural influence on events because She had a close association with Syracuse and also was indirectly involved in the events that led to Archimedes death.
There are several versions in Greek mythology of what happened to the handsome hunter Orion. I chose the one in which Orion tried to seduce the virgin Artemis (glossed over in my account) so she had him killed by a scorpion. The constellations Orion and Scorpios end up on different sides of the sky because the starry Orion wants to keep as far away from the scorpion constellation as he can.
I needed Phidias and the young Archimedes placed somewhere high so that they could see both constellations at once. Having visited Syracuse to get ideas for the book, I remembered the ruins of an ancient fort that were high above the city, so I set the scene there. To make it logical for the two to visit the fort to observe the stars, it seemed like a good idea to have the family home nearby, which put it in Epipolae.
Then I worried that since Orion dips below the horizon during the summer and Scorpio is in the summer sky, how could Phidias show Archimedes both on the same evening. A friend had a computer program that shows the position of the stars for any latitude for any day in the past or present, so I put him on the case. After considerable computer time, he determined that mid-December in Syracuse would work.
So now I had the season and location for the scene, which would determine much else. And this all occurred because I wanted to include some easy mathematics.