Is gravity just a theory

Answer 1

Yes. It's just a theory that successfully explains most but not all of the motions

of stars and planets and falling bodies that we see around us, and accurately

predicts the results of most but not all of the experiments that we can do to

test it, and places space probes exactly where we want them when we use it

to design their missions.

So far, in the 350 years or so since the theory of gravity was written by Sir

Isaac newton, that theory has been the best we have at explaining and

predicting. But the reasons are still a mystery, and it can't be proven. If

you come up with a theory that explains more of what we see and makes

more accurate predictions, then Newton's theory will be discarded and yours

will be adopted. That's how science works.

By the way ... here are a few more ideas that are just theories:

-- The Earth orbits the sun.

-- The sun's energy is the product of nuclear fusion in its core.

-- Everything is made of atoms.

-- Light and radio are both forms of electromagnetic radiation.

-- Influenza is a virus.

-- The center of the Earth is molten rock.

-- All distant galaxies are moving away from us at high speeds.