==Wrong definition== 

 In the present article we define a force as anything which causes a free mass to accelerate. Which would include gravity. But that's a wrong definition, because gravity is not a force. It's a property of space and time, which is why all objects (no matter how massive, or even if they have no mass at all, like photons) all accelerate at the same rate, on the same path in a gravity field. They're not being pulled. On the contrary, one must pull on them to STOP this behavior. Wouldn't it be nice to start out an article with a definition which isn't wrong? We owe at least that to our readers.