GOLDEN RATIO

The golden ratio can be defined in terms of a line, divided into two unequal segments in a way that their lengths meet a simple condition.

Researchers from Johns Hopkins University have discovered that the Golden Ratio exists within the human skull, putting it in the same category as pinecones, galaxies, and hurricanes all of which exhibit the special number in their shape makeup.

For centuries, this has fascinated all kinds of people, not just mathematicians. Physicists and biologists have studied it, architects and artists have used it, and worshippers have described it as a divine design.

And through the centuries, this ratio has continued to amaze its diverse fans, frequently cropping up at unexpected places.

When the ratio between these two lengths (the longer segment divided by the shorter one) happens to be the same as the ratio between the entire line and the longer segment, then the line is said to be divided in the golden ratio.
For this condition to hold good, the ratio needs to be 1.61803… with the digits after the decimal going on forever; the golden ratio is what we call an “irrational number”.
It is represented by the Greek letter phi.

why is it everywhere, now in human skull?

Examples:

It appears in the work of artists and designers from Da Vinci to Corbusier, and also shows itself in nature in pineapple scales, rose petals and many more places.
The latest such place is the human skull. If we draw an arc across the top of the skull and divide it at a key junction over the brain, the two arc-segments are approximately in the golden ratio.