inching
Explanation
The Joke
A man looks at an inchworm and indignantly corrects the name: "Inch worm? Christ, are we in the dark ages? This is a 1.588*10^33 Planck-length worm." The caption below reads: "Physicists make the worst naturalists."
The comic imagines what would happen if a physicist encountered everyday nature and insisted on using fundamental physics units instead of common measurements. An inchworm is colloquially named for its approximate size and its characteristic looping locomotion. The physicist refuses to use the folksy imperial unit "inch" and instead converts it to Planck lengths -- the smallest meaningful unit of length in physics, approximately 1.616 x 10^-35 meters. This results in an absurdly large number to describe a tiny worm.
The Humor
The humor comes from the clash between practical, everyday naming conventions and the rigid precision of theoretical physics. Calling an inchworm by its Planck-length measurement is technically more "fundamental" but is hilariously impractical and misses the entire point of why the creature is called an inchworm in the first place. The caption -- "Physicists make the worst naturalists" -- perfectly encapsulates the joke: applying physics-level precision to biology and common names is not only unnecessary but actively counterproductive.
References
The Planck length (approximately 1.616 x 10^-35 meters) is a fundamental unit in quantum mechanics, representing the scale at which quantum gravitational effects become significant. One inch is indeed roughly 1.588 x 10^33 Planck lengths, so the math in the comic checks out.