Rod Carvalho wrote a post this morning announcing a beautiful 2010 calendar created by Ron Doerfler. Doerfler’s blog is entitled Dead Reckonings: Lost Art in the Mathematical Sciences. The calendar is an example of such lost art. It is illustrated with nomograms, ingenious ways of computing with graphs before electronic calculators were common. The illustrations are pleasant to look at even if you have no idea what they mean.

Image via Ron Doerfler.

**Related posts**:

Spherical trig is a lost art. Why care about spherical trig?

The Gudermannian function gd(*x*) is another interesting relic of an early time. It is closely related to the Mercator projection and shows how to relate ordinary and hyperbolic trig functions without using complex numbers.

The image above shows solutions to the equation *u* + *v* + *w* = *uvw*. Here’s a post explaining the significance of that equation.

What a wonderful post. You’ve made my afternoon.

Gene

Image belongs to Ron Doerfler, not Rod Doerfler

Thanks! I corrected the typo. And thanks for announcing the calendar on your blog.

Thanks, John, for your post on my calendar. I had never heard of the relationship you discuss among the solutions to u + v + w = uvw. Very interesting!

Ron

While writing a post today about the concept of perception of time in the context of organizing for 2010:

http://www.beruly.com/?p=540

I was struck by how complex the concept of a calendar is. This calendar of lost mathematical art reminds us all how beautiful and powerful the human mind is! Perhaps the 2011 calendar could show mathematical concepts of time!