Physical Axioms and Attractive Forces

[tvf] “ ... I'm not sure I hit the point that was causing you to glitch.”

I’m finally sure I know what the issue is. You mention it in the following analogy..

[tvf] “Here's another analogy. If elysium were an ocean flowing over a mountain, and the mountain jiggled (perhaps from an earthquake), it would send out a pressure wave through the water that would ignore the flow of the water yet have its propagation speed determined by water pressure/density everywhere it traveled.”

I guess it’s true that great minds think alike. I was going to use this very analogy next, because sound waves in liquids (which are mostly non-compressible) propagate as pressure waves rather than as density waves.

You made a statement earlier in this discussion that should have alerted me to this issue, but I missed it. At the time I thought your reference to “pressure wave” meant the static pressure gradient in the elysium caused by a mass’s graviton shadow. Under that assumption I saw no problem, but I also didn’t get your point.

[tvf (from Feb 18, 03:24:30, near the top of this page) ] “Disturbing a medium can set off a density wave in that medium. A density wave must logically travel with the medium because it has no other reference frame. A pressure wave requires an external force to create the pressure, and acts by transmitting momentum through contact but without displacement of the molecules or other medium constituents. The force determines the frame of reference for these pressure waves, which are oblivious to medium motion.”

You suggest here that gravitons can redefine the frame of reference for light waves because they propagate as pressure variations rather than as density variations.

I see no possibility that pressure waves can behave differently than density waves in this regard. Both modes of wave propagation depend on particle-to-particle properties rather than on particle-to-remote-force properties. <u>Once the wave front is no longer in direct contact with the vibrating mountain</u>, particle-to-particle properties govern the movement of that wave front. If the particles (water molecules in this case) which support propagation all share a common velocity relative to the mountain, any wave propagating within them will share that velocity as well.

I don’t suppose you have some evidence that suggests otherwise? I know you and your think tank must have spent some time on this. And someone there must have raised this objection.

The fact that this idea survived that process is intriguing. I’m really sure I’m right about this, but ... what if I missed something?

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Larry Burford</i>
<br />If the particles (water molecules in this case) which support propagation all share a common velocity relative to the mountain, any wave propagating within them will share that velocity as well.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">I was sure we had been over this ground before, so I checked back and found it in the Members Forum from a year ago in the topic "Entrainment of Elysium". I repeat the key message here.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Larry Burford</i>
<br />this alternative seems to have the defect of predicting an ether wind, contrary to experimental observations. So - I must be missing an important piece of the puzzle.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">You ask a very good question here. I am in fact now in discussions with a referee over this very matter.

Suppose we have an undisturbed flow of a stream of water, such that its surface is flat and smooth. It would have to flow through a smooth, horizontal tube open on top because the roughness of a river bed would churn up the surface.

Now drop a rock into the flowing stream. Would the ripples spread from a center fixed where the rock dropped, or from a center flowing downstream with the water?

In general, ripples are formed from up-and-down motion of water molecules in place. That is why a floating object does not advance with a passing wave, but tends to stay in place.

In our example, the rock creates wave momentum equal in all directions around the fixed rock. Nothing is available to add momentum to the ripples to take on the stream motion. Instead, if the wave speed is x and the stream speed is y, where x &gt; y, then the ripple wave will simply develop a reduced wavelength (downstream side) or increased wavelength (upstream side). By the principle of relativity, the ripples cannot tell that the stream is moving. They simply make water molecules bob up-and-down as their momentum passes.

From the perspective of a water molecule moving downstream, the ripple simply overtakes it at a smaller relative speed, but that molecule is not given any additional lasting downstream momentum and does not attempt to follow the passing ripple.

So from both perspectives, the ripples (analog of lightwaves) should be oblivious to the stream motion (analog of aether wind).

I am still thinking about other consequences of this. Is there any chance of some experimentalist out there doing the experiment and photographing it? -|Tom|-

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I do acknowledge that this hypothesis needs further elaboration and testing. Without waiting for your next objection, I can think of one of my own. The wake of a speedboat is clearly carried downstream as the ocean flows past the boat (taking a boat-fixed perspective). But the flow speed (or speedboat speed) is greater than the speed of water waves, so the conditions I described above do not apply. (However, the speedboat analogy would be good for visualizing what happens if we try to travel through elysium at FTL speeds.)

An important property of waves relevant here is that the wave speed depends only on medium properties and not on driving force properties. When a wave passes, the medium molecules bob up and down, back and forth, but with no net displacement. The medium is undisturbed after the wave passes. So if the wave speed cannot induce net motion in the medium, how can we expect medium motion to change the wave speed?

Said another way, gravitons produce a pressure gradient in elysium near a mass that ignores elysium flow. If we create tiny ripples in that pressure gradient, they must also ignore the elysium flow.

And no, I'm not satisfied with this either. But I think we need to look closely at the wave propagation mechanism to understand better why things behave as they do. Specifically, the key probably lies in a more detailed understanding of why motion of a body through elysium and increased gravitational potential produce essentially identical effects on the electromagnetic waves in the body (e.g., its clock oscillations). -|Tom|-

I will do the experiment within the next week or two. (Film at 11:00.)

Tom, several years ago we had a phone conversation where we spoke of the analogy of faster than sound travel and the fact that an observer inside a jet engine would not feel like the sound barrier had been broken. This whole line of thought in this thread joins with the reality of breaking the sound barrier and its implications (ideologically) upon FTL travel. Like the speedboat, the wake cannot catch the FTL object in a pond of elysium. For a craft to travel beyond light speed, I have always asserted that the mechanism propelling the craft would not break the understood rules of light in doing so, an observer inside the propulsion system would not observe light speed to be broken.

Mark Vitrone

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by MarkVitrone</i>
<br />an observer inside the propulsion system would not observe light speed to be broken.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">If such an observer could peer out a window, as he approached the speed of light, he would see more stars in front of him and fewer behind because the spacecraft would run into more light beams, and fewer would catch up to him from behind. The light would also be blueshifted.

As the speed of light is exceeded, all light beams would appear to come from the forward half of the sky. At even faster speeds, even light beams from directly behind the spacecraft would appear to come from in front as the spacecraft caught up to portions of the beam that had already passed by. Eventually as the speed of the craft rose further, the whole universe would appear to emit light only from a small spot directly ahead. And the light itself would change appearance from x-rays to gamma rays to cosmic rays, and end up in the form of Cherenkov radiation.

So no laws of physics are broken, but the view would be ... unusual. -|Tom|-

TVF said: Now drop a rock into the flowing stream. Would the ripples spread from a center fixed where the rock dropped, or from a center flowing downstream with the water?

LB said: I will do the experiment within the next week or two.

I think you've already performed this experiment, haven't you? A pool of water on the Earth is moving at about 65000 miles per hour relative to the Sun's rest frame, but if you drop a pebble into the pool, the ripples are concentric relative to the water's rest frame, not relative to the Sun's rest frame (let along the galactic center).

In general, waves in a material medium propagate at "the speed of sound" relative to the medium. Such waves consist of coupled fluctuations in pressure and density. The equation of state of the medium links pressure and density (and temperature), so any fluctuation in one is accompanied by a fluctuation in the other.

You could look up Schlieren photography, which is used to film (for example) gas flows. Also, check out the Navier-Stokes equations of fluid dynamics, and the stress and strain equations of state for elastic solids.