Re: how are planets and stars 'charged'? positive? negative? neutral?

Hi,

Planets and stars are electrically neutral and the universe as a whole carries zero electrical charge.

I suppose that if you were to compare the Solar System to an atom, then the Sun would be equivalent to the positively charged nucleus and the planets would be the electrons, which are negative. However, this is a bad analogy to make because you are comparing the force of gravity, which keeps the planets in orbit around the Sun, to the electrostatic force which binds an atom's electrons to its nucleus. The main difference between the two is that gravity has no equivalent to the concept of electrical charge. So, whereas the electrostatic force between two electrical charges can attract if the charges are different or repel if they are alike, the force of gravity between two bodies is always an attraction.

Going back to the analogy of solar systems as atoms, this means that while the analogy would imply that stars would repel one another, just as positively charged atomic nuclei repel one another, in reality stars are bound to one another by gravity just as planets are bound to stars.

Jim O'Donnell