Here is what I understand of the equivalence principle. However, given that the concept is still a bit cloudy to me, please tell me if I am wrong: The equivalence principle is a phenomena where all inertial objects experience the same laws of physics. In other words, if you were going at constant speed, you would not be able to tell that you were moving unless there is a window because the laws of physics(ex. throwing an object in the air and expecting it to not fall forward) is the same. The equivalence principle states that if we were to close the window, we could not tell if we were accelerating upwards in a rocket or towards the Earth if the acceleration is 9.25. Only in cases where we accelerate to more than such, such as in a free-falling elevator, would we be able to tell that we are moving. Astronauts in space likewise experience weightlessness because all objects are free-falling together, and hence, there is nothing to push against them so they can " feel" gravity. This can all be used to explain why the apple " knows" to fall downwards. Gravity causes the apple to fall towards the Earth at 9.25 so it would meet my head. If we were all experiencing free-fall and are experiencing acceleration at the same rate, the apple would not " fall" downwards. If all that I said above was correct(which very likely it is not), does that mean our rates of accleration/gravity on Earth is different?