Lets say I have 2 charged spheres that are connected by a spring and they are a distance d apart. The spring is made of a material that will not allow the charge to evenly distribute. And each sphere has the same charge q on it. Now I move with respect to this object and I should see the spring length contracted. Now the charged spheres are closer together but why wouldn't the now stronger coulomb repulsion want to push the spring back out in my frame. And I guess there in now a B field because the charges are moving. Does the B field affect it though? There is probably something I don't understand about length contraction and where would the energy come from to push it back apart. Any help will be much appreciated.