A (Detailed) Look at the Four Color Theorem
Published:
A proof that went undone for eighty years. We’ll go from maps, to planar graphs, to Kempe chains, to the final computer assisted solution.
Blog Posts
Posts in the process of being migrated from hacked Wordpress site.2019
Putting #1 First – Deriving Benford’s Law
Published:
Looking at when this elusive “first-digit law” does (and doesn’t) apply.
Mathematicians’ Many Hats
Published:
Solving riddles about hat colors with logic and a bit of set theory.
A Variation on Bertrand’s Paradox
Published:
Understanding the importance of a well-posed problem by examining a math problem with 3 different “correct” solutions.
2017
Inside Out Universe – The (Legitimate) Hollow Earth Theory
Published:
Using projective geometry to invert the world as we know it.
Buffon’s Needles and Noodles
Published:
A probability exercise leads to an exploration of circles and other shapes of constant width.
Rainbows and Optics
Published:
Finding the reason for a rainbow by analyzing a single spherical drop of water.
2016
Spatial Reasoning Brainteaser
Published:
A simple puzzle involving engineering drawings.
Error and Multiple Measurements
Published:
Mathematically quantifying error a.k.a. being right about how wrong you are.
Buoyancy and Perpetual Motion
Published:
Debunking a convincing “free-energy” device