Halc
Registered Senior Member
Exactly. Thus a magnetic field is not a force field, for the same reason that a gravitational field is not a force field.There are no iron lumps near the magnet. Does this mean that the magnetic field does not exist?
Maybe so, but a link would help me know what you mean by this. Without units, this is nonsense. What is the spatial density where you are now?Spatial density is the concept of GR, why should you object? Space bending is a 2D image. In the perspective of a 3D image, it is the spatial density.
I don't think I mentioned a difference of acceleration in any of that. I'm comparing gravity to gravitational waves, only one of which produces acceleration.What is the reason for the difference in acceleration? You should understand that the two locations A and B will not have different g1 and g2 for no reason. Have you thought about the reason?Halc said:The sun exerts gravitational force on objects nearby. It emits negligible gravitational waves because it has negligible acceleration. Gravity is a function of mass. Gravitational waves are a function of mostly acceleration, and hence Earth generates more (about 200 watts) than the sun . Hydroelectric power plants harvest the energy of gravitational potential, and they could not generate all their gigawatts if Earth gravity only produces 200 watts of it total.
Gravitational waves are incredibly weak, and it takes an amazingly sensitive instrument like LIGO to detect it, and even then it only detects sources that actually generate significant waves at supernova energy levels.
Gravity on the other hand just requires something simple like my bathroom scale.
I also made no mention of different locations.
I don't think they give out Nobel prizes for applying a principle known for at least 400 years.If you can argue this point, you will get a Nobel Prize.A large mass moving from A to B is the same as a large mass not moving at all in a different frame. No waves involved in this.
A long rod generates gravitational waves if rotated. At some distance X from its center of gravity, it the gravity is greater if the rod is aligned with X than if it is perpendicular to a line drawn from it to X. The gravity from the rod is not 'conveyed' by gravitational waves or anything else, but changes to the gravitational field are conveyed by such waves. By this argument, no waves at all are sent along the axis of rotation of the rod since the field doesn't change in that direction. Nevertheless, an object there will be drawn by gravity to the rod.