Shaping the World
Being Flexible
Imagine a cable or a rope that is completely flexible and the exactly the same along its entire length. When we attach the ends of it to solid unmoving things directly across from one another and let the cable hang and dip in the middle it has a certain shape. This shape is called a catenary.
We can actually describe this shape with a formula involving e. With y as the vertical distance and x as the horizontal distance,
y= a/2 ( ex/a + e-x/a )
where a is a constant value depending on how close the ends are together and how long the rope is.
e in Architecture
So, there is a fundamental natural shape to hanging cables that we can describe with an equation involving e. The Gateway Arch in Saint Louis, Missouri has this same caternary shape only upside down. It is the ideal shape for an arch that only has to support its own weight, because it has no shear forces.
A More Theoretical Curve
e is also an important part of the equation for the infamous statistical bell curve which characterizes a normal distribution. A normal distribution is often used to describe how exam grades are spread out, or for instance, how male Canadian heights are spread about an average.