Thursday, January 6, 2011

Phi Day 1.61803...

Mathematicians and architects will be familiar with the Golden Ratio, a very important ratio which occurs in nature (logarithmic spirals) and many man-made things (ancient Greek temples).  More information is (here). 


In a nutshell, a line divided by the Golden Ratio into two segments will have a long segment, a, and short segment, b. The ratio of a + b to a is the same as the ratio of a to b. Expressed as a decimal, that ratio is 1.61803.


So there already exists a special day for another magical mathematical number, Pi. Recall that Pi, the ratio of a circle's area to the square of its radius, is 3.141593. Some people like to celebrate Pi day on 3.14, or March 14th.


Well, using the same logic, Happy Phi Day, January 6th!


Not everyone agrees that today should be Phi Day. There are some who advocate for October 31st in the Northern Hemisphere. More information is (here). I follow the argument, but it requires too much explanation for my taste. I will stick with today, Jan 6th, at 1803, which is 6:03 pm in military time.


Happy Golden Ratio Day!