7 February 17

Today is e Day! 2 and 7 are the first digits in the number e = 2.718281828459..., and so the seventh of February is particularly significant for mathematicians, statisticians, physical chemists, nuclear scientists, botanists, artists, . . . anyone who deals frequently with limits and boundaries and infinite series in the natural world!  My tie features abstract colored leaves, with interesting curves, edges and intersections, to illustrate limits and boundaries. The number e (usually written in italic font) is defined as "the base for natural logarithms," but its incredible significance as a universal constant shows up as soon as you start trying to calculate the growth rate of bunnies or bacteria, or to understand how a drug's concentration in your body decreases with time, or to describe how the petals on a dandelion are distributed in space. Read more about e at http://www.intmath.com/blog/mathematics/today-is-e-day-4133. I'm also proud to claim e Day as my own, because it's my first initial (as Eugene)!