This afternoon I opened a door in the house to find a dog waiting anxiously for me on the other side. It took my mind to an old comic by Gary Larson, in which lab-coated dogs are studying diagrams of doorknobs, marked up with vectors and other sciencey-looking things.

Knowing how it could change the lives of canines everywhere, the dog scientists struggled diligently to understand the Doorknob Principle

I wondered if somewhere in a dimension far away yet right here, there might be a similar comic pinned to a tetricle (a four-dimensional cubicle) featuring humans and the speed of light.