- #1
dawningparadox
- 17
- 0
As shown
Buzz Bloom said:
phyzguy said:All objects have energy. Can you name an "object" with no energy?
Buzz Bloom said:Hi @dawningparadox:
I confess I am not an expert, but my understanding about GR is that the concept of force is not used. A gravitating body, e.g. the sun, does not in GR exert a force on an object, e.g. a planet. Rather, it distorts space (and time) so the the paths follow geodesics in the curved space. One can imagine a "test particle" with infinitesimal mass-energy. Such a particle will (approximately) follow the same geodesic as a planet. Thus the mass-energy of the relatively low mass object under the gravitational influence of a massive body does not depend significantly on the mass of the object. A relatively large mass object, like a planet, also distorts space, so it will follow a slightly different path than a low mass object. This is consistent with the Newtonian motion relative to the center of gravity of two masses.
One can conceptually extrapolate from an infinitesimal mass to zero mass which exactly follows the geodesic in the distorted space due to the large mass, e.g., the sun. Any real object does not exactly follow this geodesic since it also distorts the space.
Hope this is helpful.
Regards,
Buzz
i assume by "mass" you mean "mass-energy".dawningparadox said:Is it valid to prove that an object has mass solely because of the fact that its path can be bent or altered by gravitational fields?
Thanks.Buzz Bloom said:i assume by "mass" you mean "mass-energy".
It seems to me that the answer to your question is "No." If one imagines the existence of an object with no mass-energy, then such an object would follow a path through bent space, and the path would be approximate the same as the path an object such as a neutrino or a photon with very little energy would follow.
Regards,
Buzz
Gravitational force is the attractive force between two objects with mass. It is one of the fundamental forces of nature and is responsible for the motion of planets, stars, and galaxies.
Yes, gravitational force can only influence objects with mass. Objects without mass, such as light particles, do not experience gravitational force.
Gravitational force causes objects to be attracted towards each other. The strength of the force depends on the masses of the objects and the distance between them.
Yes, gravitational force can influence objects with energy. The amount of energy an object has does not affect its ability to experience gravitational force.
The relationship between gravitational force and energy is that energy is required to overcome gravitational force. For example, to lift an object against the force of gravity, energy must be used.