Saying something is "just a theory" does not make any sense, scientifically speaking. Scientific theories provide explanations that have been tested and proven.
Don't worry, we're not actually talking about the Second Amendment. We're talking about the laws of physics!
Learn about what physicists call a "fictitious force", on this Moment of Science.
You have a long curved metal tube and a miniature golf ball that you knock into one end and out the other. How does the ball move after it leaves the tube?
The law of gravity describes and quantifies the attraction between two objects. But the law of gravity doesn’t explain what gravity is or why it might work in this way. That’s because that kind of explanation falls into the realm of theory.