Monday, April 16, 2018

Stability of Orbits

Electric repulsion due to similar charged surfaces is what keeps orbits from collapsing or flying apart at the slightest disturbance.

To see how this works, consider our Moon and what would happen if some external force were to push it hard towards our planet.

Without electric repulsion, our Moon would speed up, the force of gravity would be stronger on average, and the orbit would be elongated. Pushed hard enough, our Moon would crash into our planet.

Conversely, if the push was away from us, our Moon would start following a wider orbit, also more elongated than it is today.

However, as soon as we include the effect of electric repulsion, we see that things will quickly stabilise.



Electric repulsion and gravitational attraction

Contrary to the gravitational force which is calculated from the centre of objects, the electrical force is calculated between the surfaces of objects.

This means that electrical repulsion increases more quickly than the attraction of gravity for bodies that approach each other. It also means that electric repulsion decreases more quickly than gravity for bodies that move apart.

The net result of this is that we get a buffering effect. If our moon is pushed towards us, repulsion kicks in. If our moon is drawn away from us, repulsion decreases more than attraction. Oblong orbits are thereby restored to near perfect circles.

This is true for all astronomical bodies and the reason why collisions between such bodies are very rare.

Furthermore, we can make the prediction that if an expanding planet is changing its gravity primarily due to an increase in charge, orbiting moons will be pushed farther away. The increase in charge will trump the corresponding increase in gravitational mass.


As it happens, our Moon is receding from us by a few centimetres a year. This is attributed to tidal forces. However, it may also be due to ongoing changes in our planet's total charge.

All orbits may be changing over time, with young orbits being generally closer together than older ones.

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