The capital letters of the modern greek alphabet is almost the same as lonic alphabet. Lower case letters came to be in after 800 AD. People would usually write horizontal lines and write, right to left. In 500 bc changed the direction of writing to horizontal lines from left to right.
"The Golden Mean is represented by the Greek letter phi, (with the decimal representation of 1.6180...) is one of those mysterious natural numbers that seems to arise out of the basic structure of our cosmos. Phi appears regularly in the realm of things that grow and unfold in steps just as the Nautilus shell grows larger on each spiral by phi."