I don't care if gravity is real. Real is a metaphysical word. ;-) Gravity is useful. I studied a little bit about metaphysics which in the common term often is described by a two world model of reality and perception. If you create two worlds you need words to connect them like 'true', 'false' and 'sense' etc.. Instead of them you can use words like knowledge, experience etc. which are practical very similar but still shows that they are context dependent even if their context is huge. This stop also people who like to argument that if you cannot show it's 100% true(which you never can if somebody is not stopping argumenting) it must be false(and for them useless). I don't mean anything goes. Empirical evidence shows that you cannot stand with one leg on the ground as your other legs tries to find ground on the other side of the cliff. You simply will fall. Sometimes this will take some time so you can tell everybody it is fine but ...