Quote:
Originally Posted by Bob148
I'm not drunk but this seemed like the place to put this:
Does centrifugal force create gravitational waves or are gravitational waves only created by matter? In other words, is the gravity we experience when we go in circles artificial in the sense that there are no gravitational waves extending from a source of matter?
If you have a rotating frame it will appear as if you have a gravitational field in it and the metric (its geometry) will be a function of the angular velocity (like your perception of gravitational acceleration etc) .
If interested i can provide for you references of the treatment of going to a rotating reference frame and tying to observe the world from that perspective. I didnt find a proper link on the net yet but there is a treatment of this problem in the introduction to General Relativity by Adler, Bazin and Schiffer pg 120. If i get some online reference of this treatment i will update later.
Essentially what happens is you get a world that feels like you have gravity and there is also time dilation etc (as seen in special and general relativity). It feels as if you are under the gravitational field of eg earth but its not exactly the same because you can perform experiments to find out that the field is a bit different than the radial field of earth and its dependence with height is different etc.
What we perceive as gravitational waves cannot exist in that system if the angular velocity w is fixed (but they can exist if we have masses in that rotating system doing various movements lol although the amplitude of the waves would be ridiculously small ). However in principle if w can be manipulated and be a complicated function of time i dont see why its not almost possible to be confused and feel a spacetime that has perturbations in it that propagate and appear like gravitational waves passing through your perceived earth like main gravity space. It would be very complicated to reproduce the form but it could happen i think. Of course doing that non uniform angular velocity rotation requires energy and obscene manipulation of its time dependence it would seem. It may not be entirely possible to confuse someone very careful though willing to make multiple measurements. But it is in principle possible to make the space-time locally appear as if it is vibrating like what it does when a wave passes.
Typically gravitational waves are produced in general relativity when you have accelerated motion of masses and energy sources.
I cannot necessarily imagine how w would be changing in time to replicate all the properties of a traveling metric perturbation wave like that reported today with the dependence it has from the distance of the source etc. But you can have examples of perturbations that are propagating in that system if you manipulate w properly.
Keep in mind that even in our own real gravity earth system (which is also rotating anyway but its not the main effect) we do not have gravitational waves because of earth itself in our frame. If one was observing the solar system from a distance they would be seeing gravitational waves due to the rotation of earth around the sun but again they are tiny and almost impossible to detect. So you do not have gravitational waves every time you have gravity. It depends on other things happening too. Basically whatever is happening is affecting the spacetime geometry as function of time and the geometric disturbance traveling out is a gravitational wave.
Last edited by masque de Z; 02-12-2016 at 01:19 AM.