What is Pi?

 
A mathematician: "Pi is the ratio of the circumference of a circle to its diameter."
A computer programmer: "Pi is 3.141592653589 in double precision."
A physicist: "Pi is 3.14159 plus or minus 0.000005."
An engineer: "Pi is about 22/7."
A nutritionist: "Pie is a healthy and delicious dessert!"

 

Relativity: Two hairs in my cup of milk is too much. Two hairs on my head is too less.