Faraday's law states that the curl of E is equal to the negative of the rate of change of a magnetic field. That means that a changing magnetic field causes a curling electric field. But then, shouldn't the opposite be true? That is, shouldn't an electric field with constant circulation generate a changing magnetic flux? This would be similar to the relationship between force and acceleration, with constant mass. If a force is applied, we know that it will cause acceleration. But the opposite is true as well: if an object is accelerating we know that it is under the influence of a force. Shouldn't the law work this way: either field involves the other one? Ampere's law states that a curling magnetic field is equal to the rate of change of the electric field, plus the current density. This means that a steady current generates a steady magnetic field. Yet, a steady current means a steady electric field, and according to the above paragraph a steady electric field, hence steady circulation should cause a changing magnetic field. So why is this statement not true? Also, since an infinite straight current-carrying wire would produce a magnetic field around it by Ampere's law, would placing a wire in a magnetic field circulating it induce a current? That is, does Ampere's law hold for both sides: a steady magnetic circulation causes a changing electric flux and vice-versa? Thanks.