Why do we call the theory of gravity a theory and not a law?

I’ve always heard it referred to as the law of gravity.

The standard definition of theory is not how it is used in science.

“Gravity is a phenomenon. General Relativity is a theory of gravity. The word “law” does not have a very precise definition in physics: the sense of the word is different in “Newton’s laws”, “Kepler’s laws”, “Gauss’s law”, and a “conservation law”. People often refer to the Newtonian theory of gravity as “Newton’s law of gravity”, but theory is a better term.”—
Leo C. Stein, PhD in physics,MIT; BS, Caltech.

”Leo C. Stein is right. There are long answers about how the vernacular uses of ‘law’ and ‘theory’ do not correspond to anything technical.”

“The Special/General Theory of Relativity is not known to ever break down (as of yet). Newton’s Law of Gravity, Kepler’s Laws of Planetary Motion, Faraday’s Law, etc are all known to known not be universally correct—they work in a wide variety of circumstances and and we know the theories that supersede them (General Relativity, Quantum Electrodynamics, etc), but they are not universally true”. —Jay Wacker, Scientist (phd+postdoc MIT, former Barnard faculty)

There is a long, interesting discussion on this subject at Quora from which the above quotes are taken.

My layman’s understanding is that the ‘law of gravity’ describes what gravity does which we know quite well and the ‘theory of gravity’ is how it does it which we don’t fully understand.

Like evolution, gravity is just a theory. Any day now things may start drifting upward. Just kidding!

As indicated by others, the term theory as used by scientists is different from its use by the layman. In terms of physics, gravity has proven particularly difficult to explain.

Most science-based “fact” is technically “theory.” Most is “proven.” Math is the only thing that is 100%. 2+2=4. That’s a fact. Chemistry could fall into the 100% category too,as long as the chemistry has already been tested.

Everything else is theory. But it has gone the scientific method route. So the “fact/law/theory” started as a hypothesis, then was later shown through testing,observation,and scrutiny of scientific peers to be correct. But many hypotheses are proven by statistics. If you do x and y, then z usually occurs….

Medical science is kind of scary. Some drugs are effective in treatment, but the exact scientific reason is unknown/undiscovered.

Science is trial and error. Often scientific “fact” will be overturned , or debunked…

I have read several articles about space that mention that either the laws of gravity differ in some places, or our understanding of gravity is flawed. As some celestial calculations don’t add up.

So either certain celestial observations mean things are cheating/not behaving according to the laws of gravity, or we have the math wrong…