Solved cryptogram

The Planck constant links a photon's energy to its frequency, and its value is fixed exactly.

Physics Facts, sourced to NIST.

What it means

Light of a given color always carries the same energy per photon, and the Planck constant is the conversion factor. Blue photons carry more energy than red ones for exactly this reason, which is why ultraviolet light can damage skin and infrared cannot. The constant also underpins the modern definition of the kilogram, so it now has an exact value with no uncertainty attached.

The claim comes from NIST, and the page it comes from was read on 2026-08-27 to confirm it still says this.

This is not the kind of claim that goes out of date, which is why it was set as a puzzle rather than a fact with a shelf life.

Solve it yourself

This fact is a cryptogram here: 75 letters over 21 different ones, graded medium.

Go to the puzzle

Nearby in the collection

The facts either side of this one.

About as hard as this one

Scored closest to it by the model behind our guide to solving cryptograms.

Play a cryptogram

Every Physics Facts cryptogram · All fact collections