Gravity Part 15

And then from that, all observers, no matter what their motion is relative to each other, all AGREE on what is happening.

Otherwise, you would say that the reason you had to exert a force on the apple is because of its weight, and George would disagree; he would say that the force that you needed to exert on the apple was because the Apple has an inherent property known as mass that arises from some other force, like the Higgs Boson.

According to the Gravity principle, both of you are right, but only if weight and mass are properties that emerge from an object's RESISTANCE to resist gravity.

The apple "wants" to obey gravity, and that shows up as either mass or weight, depending on your relative motion.