twistedenginestarter
Actually Newton was sorta close but missed an important point.
Gravity only
appears to act silently, using your example of space vehicles using it to change direction, a great deal of 'latent' sound is actually produced, the enrgy has to go somewhere, which like latent heat is only released by a change of state.
One needst only observe or hear the latent sound that is explosively released when said space craft or object hits the earth out of control at high speed and changes state.
Latent sound of course, is why we have to plan our descent from altitude carefully in order to allow a managed and careful dissipation of the latent sound built up from our continual fight with gravity enroute.
If we get this and the very final latent noise dissipation stage close to the ground wrong (some call it landing, incorrectly applying the wrong branch of physics), the stupendous release of whats left of the accumulated latent noise can be very embarrasing, indeed fatal in the most extreme cases. We must control this change of state carefully.
One needs only to observe the effects of the release of latent heat in a thunderstorm to have a visual demonstration of the power.
We have seen enough pictures of the effects of the inapproriate release of latent sound to prove this thesis, these unfortunately were not then available to Newton who would have drawn this entirely different conclusion.
The SN (Specific Noise) level of the apple was just not high enough to register above the other ambient parameters.
A simple mistake but understandable in the context of the then technology, given that there were few if any machines capable of generating great volumes of noise.
