# Ritz's combination principle

> English word · Proper noun

## Definitions
1. The observation that the sums and differences of the frequencies of spectral lines often equal other observed frequencies; a consequence of quantum mechanics.

## Etymology
From Walter Ritz, Swiss physicist.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/ritz-s-combination-principle