520 day or I love you day - a math geek love story


520 or I love you day

Today is May 20th which in Chinese is known as 520 day, these numbers are pronounced Wu 五  Er 二   Ling 零. It is used to confess love since it has a similar sound to "I love you" or Wo 我  ai 爱  ni 你.

In the language of mathematics "I love you" can be written as " ρ=a(1-sinθ) ". This polar equation when graphed will give the curve shown below called a Cardioid. Aptly named since it derives from the Greek word καρδία (cardia) which translates to "heart".

                                                                                                                              (Graph source)

"The name cardioid was first used by de Castillon in Philosophical Transactions of the Royal Society in 1741. Its arc length was found by la Hire in 1708. There are exactly three parallel tangents to the cardioid with any given gradient. Also, the tangents at the ends of any chord through the cusp point are at right angles The length of any chord through the cusp point is 2a." Weisstein, Eric W. "Cardioid." From MathWorld--A Wolfram Web Resource.

Just how many times has this eloquent mathematical expression led me into sessions of passionate love making or perused by beautiful woman wishing to run away and be lost in romantic paradise. Glad you asked. I'll answer with more mathematics.

                                                                                                                  image sources: (1) (2)