I have posted some related questions, but I am struggling to understand gravitation waves. I understand that an essentially stationary system such as the sun-earth forms a static distortion in the space-time continuum and therefore produces no measurable gravitation waves. As I understand it, this is why the gravitational position of the sun relative to the earth differs from the optical position we see in the sky by about 8 minutes. However, if you add the moon to the system, it seems that this system cannot be described as a static distortion but is inherently dynamic and should generate gravitation waves. They would be small compared to those recently measured by pairs of black holes, but they are much closer and should be much easier to detect. I know I am misunderstanding something, but I would appreciate someone helping me clarify things.
I think the answer to your question is that the earth-moon-sun dynamic system does generate ripples in space-time but their amplitudes are too small to be measured by current methods - their signal is simply lost in the noise.
A footnote: The 8 minute displacement in optical position of the sun and the actual location in space of the sun is due to the finite velocity of light - the light we see was emitted from the sun 8 minutes ago during which the sun has advanced along its trajectory in space.
When black-holes of multiple solar masses merge they produce a strain in space of the order of 10^-21 cm (from 1st discovery of GW). You can imagine the strain produced in our Sun-Earth-Moon case! It is difficult to detect such infinitesimally small strain.
You yourself generate gravitational waves when you move. But as said above the effect is too small to measure.
There is also the problem that we are inside the Earth-Moon system. To detect them, you really need to be much farther away. A detector in the outer reaches of the Solar System would be preferably to avoid "near-field" effects.
I'd agree with Dwight. But remember, some 20-30 years ago there were effects we could NOT detect with the equipment of the time. And we still have the noise swamping small signals.
Remember though that LIGO has been in development for about 20 years and the noise floor is close to being limited by fundamental physics, photon quantisation of the lasers for example. The frequency is also crucial and for the Earth-Moon system, that's once cycle per month. LIGO and even eLISA will have minimum frequency ranges far higher.
First of all the 8 min delay applies equally to gravity as light as gravity also only travels at light speed. it seems counter intuitive that you could remove the sun and we would continue to rotate round a none existing object for 8 minutes Secondly all mater produces gravity waves but the instruments such as LIGO cannot detect them because the lower the frequency the higher the background noise so LIGO is useless below 10 Hz and does not come into its usfull range until 100 Hz at best. The frequency of the moon is the reciprocal of one month and that of the earth even longer at 365 days which can easily be detected with the simplest gravity meter but not by any instrument looking for distant gravity waves. The gravity wave experiments are more than everything else just confirming the correctness of the speed of gravity and the existence over extended distances of the low attenuation of gravity with time And distance in free space. My own opinion and field of study is the possible half distance in lead of gravity rather than the more usual half life . The neutrino is an example of this with a half distance in lead of 1 light year
This is a very fascinating field of research and could bottom the problem of the graviton and remove the requirement for an infinite anything
In my opinion only theory of quantum gravity will provide the answer to everything.
" In my opinion only theory of quantum gravity will provide the answer to everything." Hardeep Thakur is almost certainly right, We know that the gravition looses no energy or mass or velocity while travailing through free space and does not we think suffer from Doppler shift We need to know the half distance in lead of the graviton like we do for the neutrino (1 light Year). This information would almost certainly unify cosmology and Quantum Mechanics
Start with the information that the Earth-Sun system and the Earth-Sun-Moon system are both dynamic. They are not static. They both accelerate. Both systems will therefore generate gravitational waves that are too small to measure with current equipment . The Solar System radiates about 5000 Watts in gravitational waves. This is miniscule. Then remember that gravitational waves and a gravity field are not the same thing. The general relativistic effects of the Solar System gravity field are well established.
The Sun, Earth and Moon system does generate static gravitational waves...please take a look at my paper (and experiment now with lots of data) https://www.researchgate.net/publication/342851935_A_Model_of_Gravitational_Waves_Based_on_a_Modified_Yukawa_Potential
Why did we miss this? Because General Relativity does have some flaws, including the singularity which even Einstein felt was a mistake. The gravity waves generated from the merger of two large objects is just the result of modulation of the static gravitational waves from those objects. Think of the static gravitational waves as a local oscillator, when they start moving there is a Doppler shift and the Doppler shift of the two gravitational sources produce an intermodulation frequency between 20 and 500 Hz, typically. We predicted those because regardless of whether we understand gravitational waves, we know that moving objects will make a change in their frequency (it's called perturbation theory). But we missed the fundamentals of general relativity and only got a few working pieces of it, so we only expect gravitational waves from accelerating objects. Anyway, if you build the same apparatus that me and my colleagues did, you can provide additional data and we can bring physics into the 21st century
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