What is a "theory?"
It's more than you'd imagine...
[The image was taken from the E tower of the Golden Gate bridge (between San Francisco CA & Marin County) on its opening day in 1937]
θεωρία [theoria] is ancient Greek for “the act of looking;” θεοριν [theorin] were “official viewers” sent by each city/state to observe & report on the quadrennial Olympic Games […in the 6th c. BCE each city in Greece was also a “state,” with its own laws, government, currency, etc.]
From this beginning the term became attached to the act of interpreting experience, and by the 14th c. CE had become attached to efforts to generalize about the origins of observed phenomena
For example, Greeks in the community of Samos [in present-day Sicily] led by Pythagoras [571-490 BCE] had noticed that the Egyptian system for re-measuring fields adjacent to the River Nile after annual flooding used a ‘right-triangle,’ which was 3units on the short side, 4units on the longer side, which produced 5units on the longest side: the “hypoteneuse”
Pythagoras realized that every such triangle had the same ratios, so the “Pythagorean theorem” expressed this fact theoretically: the sum of the squares of the two straight sides of a right triangle = the square of the hypoteneuse: a² + b² = c²
In this way a theorem became the descriptive term for “scientific” observations (“science” is a derivation of the Latin scientia, meaning “knowledge”): observations that generalize a truth about all expressions of a relationship
When Darwin, a young “naturalist” aboard the British ship Beagle on its exploratory voyage [1826-1831], went ashore on the Galapagos Islands, he noticed that a members of a species of finch on different islands had distinct beaks
Darwin realized, on exploring the islands, that the birds’ beaks were adapted to the kind of seeds that formed their main diet: this generalization about differences within a species became the basis for his theory that differences arise as adaptations
He published his elaboration of this evolutionary theory in the “Origin of Species” [1859], which proved the traditional belief—that species were fixed in their created forms—to be false
This remains one of the best examples of the fact that the expression of a theory can have revolutionary consequences
Only a half-century later Einstein’s theory of the relativity of all motion to the speed of light produced revolutions in physics & astronomy that are still unfolding
Think about this the next time you hear that a claim is “just a theory…”