I was thinking about gravitational waves, and I found out that I may have a doubt about their production.
Assuming the whole calculations find a wave-like solution to be understood, I was wondering about the real reason/way by which gravitational waves are produced: I have always been taught that a wave is produced by a perturbation created by the motion of an object.
Gravitational waves arises when huge massive bodies do perturb the space-time itself but here it's the unclear fact: it's the motion of masses itself that perturb the space-time? Because I'm having some hard times in understanding if gravitational waves are/are not produced simply by a moving massive body..
Because in this way, "we too" may produce gravitational waves (whose frequency would be extremely small).
Best Answer
Gravitational waves are generated in a manner analogous to electromagnetic waves.
Classically, changing electric or magnetic fields can generate electromagnetic waves, a radio antenna being a good example, and also radiation is emitted by accelerating or decelerating particles. Maxwell's equations are "simple" enough as one is dealing with vector fields. This is reflected in the quantum mechanical carrier of the electromagnetic field, the photon, which has spin one.
In General Relativity the mathematics is more complex, still, gravitational waves are expected for "changing gravitational fields" , in quotes, because the gravitational field emerges from the space curvature posited by GR. Since one is dealing with tensor fields , the quantum mechanical carrier (in the effective quantizations of gravity used up to now) is the graviton of spin two.
This illustrates the space distortions as the wave passes:
So, as with electromagnetic waves,
So under certain conditions an accelerating mass can radiate gravitational waves. The effect on planetary orbits , though present due to the emission of gravitational waves, is very small , because of the great weakness of gravity.