lightspeed comm

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">[tvf]:The bottom line is that the propagation speed of gravitational force can be no less than 20 billion c.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote"><i>Originally posted by Guarionex</i><br />Let me just say, at least for now that the astonishing speed of gravity is questionable to me. It almost looks like: Limit as V(g) --&gt; infinity = action at a distance = curved space-time = field theory. Could everyone be saying the same thing, each in his own way?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">v_g = infinity is not logically possible precisely because it is action at a distance and violates the causality principle. See "Physics has its principles" at metaresearch.org/cosmology/PhysicsHasItsPrinciples.asp

v_g &gt; 20 billion c makes no sense in a Big Bang cosmology, but might make sense in an infinite universe unbounded in scale as well as time and space. See my book <i>Dark Matter, Missing Planets and New Comets</i> for a complete, assumption-free cosmology in which this speed makes perfect sense. See the book <i>Pushing gravity</i> for the complete gravity model that sets constraints on graviton size, mass, speed, flux desnity, etc. to see how this fits into the bigger picture in a realistic (non-Big-Bang) cosmology.

So no, everyone is not saying the same thing.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">This also clearly shows me why the Michelson-Morley experiment failed. Just imagine this experiment is done inside a glass container filled with water with the scientists doing the measurements also inside it. While they measure the velocity of light as .75c to and fro, we see the container go by us with velocity v and the light inside it going at .75c-v as it approaches the back mirror and .75c+v as it is reflected from it. In other words, light is being dragged by the medium. Forget about LR, SR... just simple NM (Newtonian mechanics).<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Reality is not that complicated. Moreover, all the world's physicists who have focussed their attention on the M-M experiment and the nature of light for the past few centuries have not overlooked the obvious.

As Richard Feynman taught us, light has a wave speed c "in vacuuo", which we can interpret to mean in its own native medium, the "light-carrying medium". This medium is now called "elysium" to remind us that it is entrained by matter and is synonymous with the gravitational potential field. Then when light passes through a secondary medium such as glass or water, its speed never changes from c. However, the molecules of that medium absorb and re-emit light at regular intervals that depend on their density. Each absorption-emission event causes a delay, typically 10 nanoseconds. But in between such delays, the speed is always c. So the rate of progress of the light through the medium depends simply on how often the light gets absorbed and re-emitted.

But the bottom line is that the speed c is unaltered by any secondary medium. So the meaning of the M-M experiment is either the SR meaning (light speed is independent of the speed of the observer) or the LR meaning (elysium is entrained by matter). With SR now falsified, we are left with the latter choice. The M-M experiment (confirmed by GPS to much higher precision) was null, and should have been because the Earth had no motion relative to the entrained local elysium. But the Sagnac and Michelson-Gale experiments (1913 & 1925, respectively), which were M-M experiments on a rotating platform, did show fringe shifts because the rotating platform was real motion with respect to the elysium.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">[tvf]: Your comparisons are not being made across space at a common time, but across space and time<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Not relevant! Respect to the spaceships or rockets Lets attach two equal rods between them, front and back before they even take off. This ensures they are parallel to each other.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">This is again a failure to understand SR. There is no such thing as a "rigid rod" in SR, as exemplified by the barn-and-pole experiment. In one frame, the pole is longer that the space between the barn doors and cannot be trapped inside. In the other frame, the barn doors are farther apart than the pole is long and trapping should be possible. However, in SR, time varies along the length of the pole as viewed from any other frame. So for the rest frame, the leading edge of the moving pole exists at one time, and the trailing end exists at a different time. [N.B. This has nothing to do with light propagation delay.] The same is true for your rod between the spacecraft. It does not do what you want because time is not the same at both ends of the rod as viewed by the other ship.

You will be trapped in paradoxes forever until you "get" this basic concept in SR, or switch over to LR.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Since the antenna idea wasn't welcome, we will install two lasers (with zero divergence beams) and a pair of sensors in each rocket to detect each laser beam. Again, the lasers and sensors will be orthogonal to the axis of either rocket. At T0 they will be orthogonal to the direction of travel.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">That condition is contradictory to the requirements of SR, which insists that orthogonal to the direction of travel in one frame is non-orthogonal in the other frame. We observe that effect every day. Light from the Sun is emitted orthogonal to Earth's orbital velocity vector in the Sun's frame, but arrives at Earth from the Sun's retarded (non-orthogonal) direction.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">lets synchronize the clocks as we usually do here on earth. Then lets wait a long time to ensure sync. Then we can sloowly start moving be applying a small constant force.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">In SR, a large force applied for a small time or a small force applied for a long time yield the same degree of clock desynchronization with position. That had better be true, or SR would be a self-contradictory theory, which it is not.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">I read your [GPS & twins] article. You state in it, not to quote you exactly, that the ship in orbit will see the Earth go back and forth in time as the spaceship was coming and going around its orbit. Whether perceived or real, this is forbidden in SR. Hence it leads me to conclude that you made a horrible computational error. Einstein himself would have had for sure made certain that his equations didn't lead to such an event.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">I'm sorry to shatter your illusions, but I am quoting standard SR. Lots of similar examples exist. Relativity's answer is simply that these "time reversal" events always take place outside the observer's light cone, so they can never be seen or produce any real causality violations. But

Tom, you say:

"v_g = infinity is not logically possible precisely because it is action at a distance and violates the causality principle."

Taking a page from quantum mechanics, what if we were to say that it is only *measured* to be infinite due to some principle of the universe limiting the information we extract from measurements of bodies moving faster than c? This should not be unexpected, I think, because measurements require interaction and we commonly require electromagnetic interaction, which occurs at c.

What do you make of this suggestion?

mhelland@techmocracy.net

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Some time back I read in a science magazine... <hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
The only thing that makes sense is predetermined orbital paths (with predetermined variation). This in turn implies action at a distance or curved space-time theory. At least those two can keep the planets in their orbits, even if we don't like them. The speed of gravity theory would send the planets flying off the same way the speed of light would, but just a little later in time.


guarionex

The questions are never going to be answered this way. You keep going in circles over and over and learn a little if that. The answers are out there so they say.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by mhelland</i>
<br />Taking a page from quantum mechanics, what if we were to say that it is only *measured* to be infinite due to some principle of the universe limiting the information we extract from measurements of bodies moving faster than c?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">That argument was tried by relativist Steve Carlip to save the idea that gravity might propagate at the speed of light. He actually proposed exactly what is required to cancel the 20" angular difference between the direction of the Sun's light and its gravity: an observer-velocity-dependent force of just the right size to hide the propagation delay of gravity.

However, we were able to prove that even this "save-the-theory" concoction was not possible. The argument below is lifted from one of my published technical papers, but perhaps you can catch the general drift of it anyway.

"If gravitational aberration were non-zero, the angular momentum of an orbit would progressively increase with time, an effect that is not observed. Real orbits conserve orbital angular momentum to the accuracy of all observations, except when tidal or non-gravitational forces operate. Carlip claims that the conservation of angular momentum needed by GR justifies the cancellation of transverse aberration. He claims this cancellation is not magical, but arises naturally in the mathematics when one imposes angular momentum conservation.

"It is true that imposing angular momentum conservation cancels aberration, but that begs the question. What physical justification exists for simply imposing orbital angular momentum conservation into equations when orbital angular momentum is not conserved by nature for other types of force? McCarthy [23] has pointed out that, to the Moon, the offset of the direction of Earth’s gravitational force due to tidal friction is indistinguishable from the offset of the direction of Earth’s gravitational force due to aberration. So if gravitational aberration exists after all because gravity propagates at lightspeed, but is cancelled by a velocity-dependent force provided by nature to conserve angular momentum (as Carlip claims), then nature must also cancel tidal friction because it has no means of distinguishing one type of non-central force from the other. However, that is contrary to observations. But how could the Moon possibly know when to cancel a non-central force component, and when to respond to it?

"The only logical answer to this dilemma is that no such mysterious, deus ex machina force exists because gravity has no aberration in need of canceling. In that case, we may be certain that gravity propagates much faster than lightspeed."

-|Tom|-

I think you misunderstood my proposal, Tom, but I may be mistaken as well.

Here is what you say about the speed of gravity:

1. We may be certain that gravity propagates much faster than lightspeed.

2. v_g = infinity is not logically possible precisely because it is action at a distance and violates the causality principle.

I am suggesting that the speed of gravity is finite and greater than c but due to some unavoidable consequences of measurement using light we measure the speed of gravity to be infinity. These circumstances appear consistent with your requirements, do they not?

mhelland@techmocracy.net