This post is (hopefully) the first of a series about the use of scientific terminology in the vernacular. This is a topic that I’ve always found fascinating, mainly because it really clarifies how laypeople understand science.
Literally, the term quantum, from the Latin quantus (“how much”), refers to an indivisible amount of energy (but it hardly seems to mean that anymore, even in physics). An electron’s quantum state describes its current properties; a quantum leap is a change in its properties.
In physics and chemistry (where I first encountered the term), a quantum leap refers to an electron’s instantaneous movement from one energy state to another. The novel (when it was new, anyway) aspect of this theory is that this movement is discrete, rather than continuous, as was predicted by Newtonian physics.
The term quantum mechanics was coined in 1924 by Max Born. Since then, quantum physics has entered the mainstream. People talk about it and read news about it, even if (like me) they barely understand it, if at all. Originally, it was used somewhat correctly, referring to a sudden change, as opposed to a slow, evolved one.
Now, however, it’s used all over the place, often to mean a very large change. Given that the term really refers to electrons, which are very small, I find this quite ironic. As they say, small things amuse small minds…