Recent content by axl

that's _not_ all there is to it, dexter. One must postulate the equivalence principle, i.e. the gravitational mass of a body is identical to inertial mass of the same body.

In the particle frame, the particles have no relative velocity, so there is no current. The particles will only be repeled by one another. You can evaluate the physics in the most convenient frame.

Don't be sad. All of you dummies are wrong: In the case of the helicopter, there is work done to move the air to keep the helicopter aloft. The helicopter's engine supplies the power (work/time). In the case of the magnet on the iron bar, nothing is moving and there is no work done. There...