Red Shift and lost energy.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by rousejohnny</i>
<br />So tommorrow at approx. 6am EDT the gravimeter will detect aphelion?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Yes.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Also, I have not been able to find an exact time for the phenomena, all the data I could find says 11GMT or UT, they always are rounded off.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">"Aphelion" is not a well-defined event. If you mean when will you be farthest from the Sun, that depends on where you are on the Earth as it rotates. If you mean when will the center of mass of the Earth be farthest, the date and hour of that will depend on the phase of the Moon. If you mean when will the Earth-Moon center of mass be farthest, that depends (slightly) on where the other planets are. And so on.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">What I am trying to say, is that if we know the exact time aphelion is to occur and we can measure when we start accelerating back towards the sun (the reason I said jolts is because the acceleration would only be for an instance),...<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Nothing about acceleration "starts" or changes at aphelion. The Earth is accelerating toward the Sun at essentially the same rate immediately before, during, and after aphelion, however it is defined. If that were not so, Earth could not stay in orbit. Stopping the Sun's acceleration would be the equivalent of "letting go" when you are on a rapidly spinning turntable. You would go flying off in the direction you were last traveling instead of continuing a roughly circular motion.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">...if the gravimeter shows it happens anywhere between the point of aphelion and approximately 8 minutes later, this would prove that gravity is faster than light, and may show how much faster.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Gravimeters verify the predicted behavior of Newtonian gravity in all instances. And Newtonian gravity has infinite gravity speed built in.

No gravimeter has enough time resolution to measure the actual speed of gravity. Binary pulsars set the tightest lower limit: greater than 20 billion times the speed of light. -|Tom|-

So in an eliptical orbit, when we are making our journey from aphelion to perihelion, the instance we begin the radial change in distance, oneway or the other does not represent a radial acceleration? If aphelion is 0 and perihelion is 1, does not the instance we move from 0 towards one represent an acceleration, radially.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by rousejohnny</i>
<br />So in an eliptical orbit, when we are making our journey from aphelion to perihelion, the instance we begin the radial change in distance, oneway or the other does not represent a radial acceleration?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">No, there is no change in the radial acceleration at those moments.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">If aphelion is 0 and perihelion is 1, does not the instance we move from 0 towards one represent an acceleration, radially.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">It is clear that you are confusing "radial acceleration", which occurs continually for an object moving in a circular orbit at a fixed distance, with radial speed changes. Acceleration is a vector (i.e., it has size and direction), while radial speed changes are simple scalars (represented by a single number or property).

Radial speed changes could be detected by doppler shift using a sensitive spectrometer. Lots of people study doppler shifts in celestial bodies. Some exoplanets have been discovered by seeing such shifts. But this tells us nothing about the speed of gravity because these changes are too small and too slow to tell if they occur on time or with a short delay. -|Tom|-

I see, so this morning the Sun was blue-shifted, and there was an effect on the gravimeter?

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by rousejohnny</i>
<br />I see, so this morning the Sun was blue-shifted, and there was an effect on the gravimeter?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">No, a gravimeter would not have noticed because there was little or no change in the acceleration or the distance of Earth or in the Sun-Earth gravitational force. But when the center of mass of the Earth-Moon system gradually changed from receding to approaching the Sun (a very smooth process with no "jolts"), the doppler shift (observable only with a spectrometer) gradually changed from positive to zero to negative. -|Tom|-

Thanks Tom!!! I kept looking at this online gravimeter and saw nothing (not that I would have known what to look for). For anyone interested, here is an online seismography data sight.

www.physics.hmc.edu/research/geo/seismo.html