Butter-side-down papers

This short post exists so that I can link to it in the future—most immediately from an upcoming post about sex and gender—and not have to constantly explain what I mean.

About thirty years ago, as I sat at the breakfast table reading the news, I burst out laughing. Kelley wanted to know what had tickled me and I explained that I had just read a proof, by Robert Matthews of the University of Aston, that, indeed, toast does tend to fall butter-side down:

We investigate the dynamics of toast tumbling from a table to the floor. Popular opinion is that the final state is usually butter-side down, and constitutes prima facie evidence of Murphy’s Law (‘If it can go wrong, it will). The orthodox view, in contrast, is that the phenomenon is essentially random, with a 50/50 split of possible outcomes. We show that toast does indeed have an inherent tendency to land butter-side down for a wide range of conditions. Furthermore, we show that this outcome is ultimately ascribable to the values of the fundamental constants. As such, this manifestation of Murphy’s Law appears to be an ineluctable feature of our universe.

— Tumbling toast, Murphy’s Law and the fundamental constants 1

Since then, whenever one of us sees something perfectly obvious proved scientifically, we grin. Butter side down…

For which Matthews won the Ig Nobel Prize ︎