Why is the speed of light expressed as a little c?
Short for a latin or greek word, or just arbitrary?
Well, according to this site, it’s short for celerity. But I’m sure there’s more to the story than that.
In the book E=mc^2 by David Bodanis, he states, “It has this unsuspected letter for its name probably out of homage for the period before the mid 1600s when science was centered in Italy, and Latin was the language of choice. Celeritas is the Latin word meaning “swiftness” (and the root of our word celerity).”
I hope that helps.
It’s a commonly practiced convention…
Many constants are expressed as lower case letters, whether using the English or Greek alphabet characters. For the speed of light, we often see a ratio of c/C meaning the speed of light for non-ideal conditions © vs. speed of light in a vacuum ©. This convention is followed in many applications in physics and engineering. - Jinx