With science and religion dominating our perception of life, death, love, and the universe, do any of us really consider where these time immune concepts originated? Whether you are religiously or scientifically minded the ancient Greeks began a multitude of studies that are still in practice today. It was the ancient Greeks who began philosophical, scientific, and theological studies in order to explain the unexplainable when looking at the night sky.

One such ancient Greek, a mathmetician named Eratosthenes pondered the significance of the universe and his place in it, he would gaze (it is said) at the night sky and after a while he would notice things which unknown to him at the time was destined to shape our modern-day understanding of our planet as a sphere. The ancient Greeks as a whole noticed that the night sky, as seen from Samos and from Alexandria had the same stars but where in a different position? It is not noted how they traversed the distances between the two places to make these observations, but the ancient Greeks were great sailors, so we can assume they did drawings from one place and the other then made comparisons.

This story claims… Eratosthenes noticed that a stick, when planted in the ground would cast different shadows at different times of the day, and with the sun directly overhead would cast virtually no shadow at all, and at dusk or dawn the shadow would be at its longest. Eratosthenes observed two sticks of equal length one in Aswan and one in Alexandria at the same time of day, it is also unclear how he did this but maybe a friend helped him with his studies, or maybe Eratosthenes himself visited both places and made observations at the same time of day but on different days, whichever it was is not that important but what is important where his findings. He noticed that the two shadows cast by the sticks, at the same time of day, were of different lengths!

Now at this point, Eratosthenes considered what this revelation meant for his research and gained a remarkable insight. The two sticks had been carefully placed upright, and at right angles to the Earth, so if the Earth was flat as it was percieved to be in the ancient world, he reasoned that the two sticks would be parallel to each other, and since the sun is so far away, the rays of light travelling to each stick would also be parallel, so if the Earth was indeed flat, both shadows would be the same length at any one time of day, but this was not the case. This was simple elementary geometry in action, if the sun, on a flat Earth, was shining directly over one stick and casting no shadow, you would expect the same outcome with the other stick, and so cast no shadow? But on the other stick Eratosthenes recorded that a very clear shadow had been cast. His further studies showed that the two sticks would always cast different length shadows at any given time of day.

These findings were pointing at only one possible answer, and Eratosthenes concluded that although the two sticks were both at right angles to the Earth's surface, they were not parallel to each other, and that could only happen if the Earth's surface was curved. To be fair, the Greeks had long suspected the Earth's surface to be round, and Eratosthenes experiment did much to prove this theory.

Apart from all the other things the ancient Greeks began, reasoning through mathematics and logic would prove timeless for mankind, the quest for a greater understanding of the universe had begun, and Eratosthenes could be considered a pioneer, he had established a template for investigation, a basic method that science could apply in its geometrical studies. Eratosthenes did many more things with 'Euclid's' mathematical elementary geometry but above all he had proven beyond reasonable doubt that our planet, our home, was indeed round.

Another Greek tale later…JDA.