when Issac Newton discovered the law of gravity, then what exactly did he discover? Apples keep falling from trees. He added three words which had existed before in the English vocabulary, and coined the term, 'Law of Gravity'.

Is there such a thing as the law of gravity? I have misgivings, because physical laws are universal laws, which cannot be defined. I mean, if we discover a law of gravity, then we are bound to look later at the law of gravity, as false. Because, if the conditions under which the law of gravity prevails, change, then the law will cease to exist.

There is no law of gravity I assume, on the moon. What I want to point out as a possibility is, that are ideas a figment of the imagination? If so, then what is imagination? What exactly did Newton see, when he saw the apple fall from the tree, if he did not see it in his imagination? The idea of the apple falling, had nothing to do with the law of gravity. If he was watching the apple falling, and was aware of the apple falling, then how was he also aware of the law of gravity at the same time?

I understand that science is the study of phenomena, but the apple dropping was one phenomenon. This makes me conclude, that Newton associated the law of gravity with the fall of the apple. I emphasize the word 'associated'. His law of gravity is as relevant as any medieval work of science, or any work of science of the renaissance era.