REVISED: Light's speed is relative to its medium's

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Allen W. McCready</i>
<br />(Go easy on me, please.

Allen W. McCready
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McCready,

I think you are on the right track. But consider that the vehicle (spacecraft, earth) is not the “medium”. It is the “inertial frame”. The light speed regulating medium would surround the vehicle and probably be inside it too, but such a medium has not yet been identified, although there is plenty of evidence that it exists.

Think of what I just said in these terms: A train carrying a whistle is not the “medium”, it is the “inertial frame” which the whistle is stationary with. But the speed of sound is NOT determined by the speed of the inertial system but by the medium (the air) through which sound travels. Inside a closed train car or airplane, the “local medium” (the local air inside the vehicle) is carried along with the car or airplane as they travel through space, so here we have a small “local medium” (the air inside the vehicle) traveling through a larger greater “medium” (the air outside the vehicle).

Some theoretical physicists have speculated that maybe the electric and magnetic fields of space constitute a “medium” that regulates the speed of the photons that travel through them. Keep in mind that the fields can travel through space in groups, such as in areas of moving plasma.

A physics professor in Taiwan has developed a “local ether” theory based on the local gravity fields of astronomical bodies acting as a “local ether”. This would account for the result of the Michelson-Morley experiment.

Here is one of his basic papers:

“A local-ether model of propagation of electromagnetic wave”

qem.ee.nthu.edu.tw/f1a.pdf

There is often a lot of confusion about the difference between a “medium” and an “inertial frame.” A medium can stand still while a small object (like a spacecraft) moves through it. A larger medium, like the strongest part of the earth’s gravity field, can travel through space with the earth, near its surface.

A moving “inertial frame” can carry things along with it, such as a gun with bullets. If you fire the gun into space from your spacecraft, the bullets will have the speed of your spacecraft plus the speed of their normal projection from the gun. This is like the old “projectile” hypothesis of light.

However, light is generally not looked upon as a “projectile” with mass, like a gun bullet. It is looked upon more as an electro-magnetic “wave” group. In this case, if your spacecraft is moving through a greater medium (such as the sun’s gravity field) then the light photons should go out behind your moving spacecraft at the speed of “c” relative to the medium, but at a speed of “c + v”, relative to your spacecraft, with “v” being the speed of your spacecraft through the medium. In front of your spacecraft, the light should go out at the speed of “c – v”, relative to your spacecraft, but at "c" relative to the medium.

This concept is based on Dr. Su’s “local ether” theory (and mine too).

Of course, other people might disagree with me and Dr. Su.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by DAVID</i>
I think you are on the right track. But consider that the vehicle (spacecraft, earth) is not the “medium”. It is the “inertial frame”. The light speed regulating medium would surround the vehicle and probably be inside it too, but such a medium has not yet been identified, although there is plenty of evidence that it exists.
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Excellent and thanks.

Yes, my terminology/phraseology was imprecise and I will revise it accordingly. As you said, the spacecraft is not the medium for light travel. Something else is. A question at the core of my hypothesis is whether that medium moves with the spaceship or the spaceship moves within the medium. As you stated later, the air within an airplane is the medium for sound. In fact, one of my supporting analogies with lots of empirical evidence that I used to conceptualize with was sound speed within an aircraft traveling faster than the speed of sound.

Since a gravitational field, as you stated, may possibly be a medium for light travel, and since the earth's gravitational field appears to rotate with the earth, then there is more reason to believe that the experiment I mentioned showing light speed to be independent of direction within that rotating gravitational field supports the hypothesis. One of the relevance quandaries my spacecraft scenario faces is whether there is a medium within the spacecraft that moves with the spacecraft and is therefore inertially separate from the medium surrounding the spacecraft. Of course the spacecraft is matter and should have a gravitational field of its own that is inertially separate, though relatively weak.

If it is a point you were making, I also understand that the speed of light travel may be controlled by things other than the medium or controlled by things that are only part of or one of many attributes of the medium.

One of the many aspects to this topic I find intriguing is what the impact would be on space travel, when spacecraft speeds get to be of the magnitude where differences in light speed would be perceptually significant to occupants. Even at one quarter the speed of light, occupants could have tremendous difficulties coping if the hypothesis is false. Consequently, this issue has probably already been given lots of expert thought. I don't know what the earth's rotational speed is, but it was apparently not too slow for directional differences in the speed of light to be tested in the experiment I mentioned. Perhaps such an experiment in a space probe already is awaiting the right cost/benefit ratio.

I have to get ready to go on a business trip for several days. When I return I will digest the rest of your message and the references you provided, then possibly respond again.

Thanks again,

As I understand you, you are saying that you found an experiment that claims that the earth's rotation can not be detected. There are experiments which have detected the rotation of the earth. The Michelson-Gale being the most famous. This means the velocity of light is different going east from going west. The Haefle-Keating experiment found that the time dilation of clocks was different going east versus going west. So the earth's rotation can be detected and this implies that light velocity is not the same for every direction on the earth.

I found a useful series of hyperlinked lectures on the Internet at galileoandeinstein.physics.virginia.edu/...res/lecturelist.html . These lectures are by Michael Fowler at the University of Virginia. These lectures cover the topic of light, relativity, etc. from Galileo's time to the present in fairly straightforward fashion. Consequently, I am slowly digesting this material, using my possibly very naive hypothesis as a personal catalyst.

However, at this point, I must still be missing something simple, because I just came up with the following paradox concerning an example from the above lectures that is supposed to illustrate why time slows for one "inertial frame" that is moving at a constant velocity relative to another encapsulating "inertial frame". Hopefully, I will find the answers as I read more of Fowler's lectures.

THE PARADOX?

Using what appears to be a typical example, the theory of relativity, as it relates to a slowing of time, seems to hinge on a light pulse moving between two mirrors in a “light clock”. This light pulse moves at the same speed, “c” (186K miles/second), as perceived by both an observer on a moving railroad FLATCAR (representing an inertial frame) carrying the light clock and a separate observer standing on the railroad TRACKS (representing another inertial frame), who is watching the departing FLATCAR. The light clock’s two mirrors are aligned across the width of the FLATCAR, perpendicular to the length of the FLATCAR. To the observer on the TRACKS, the receiving mirror (not the light pulse) moved distance, “d2”, in time “t”, while the light pulse traveled from the other mirror. To the observer on the FLATCAR, the receiving mirror did not move relative to the other, so the distance the light pulse traveled was “d1”, which was the direct distance between the mirrors. “d2” is greater than “d1”. As I understand the relativity theory, the only way the speed of light can simultaneously appear to be “c” to both observers is if time for the light clock and its observer on the FLATCAR slows proportionately relative to time for the observer on the TRACKS.

However, if a second, but identical, light clock added to the FLATCAR were aligned pointing toward one corner of the rear of the FLATCAR, then “d1” would be greater than “d2” for that second clock. That is, the receiving mirror would have moved closer to the first mirror while the light pulse was traveling. Using the same logic used for the first light clock, that would mean that time for the rearward pointing light clock and its observer on the FLATCAR would have to speed up proportionately, relative to the observer on the TRACKS.

Consequently, to the observer on the FLATCAR, time would have to slow to account for the first light clock, yet simultaneously speed up for the second light clock…a paradox.

Another paradox is that since this first paradox appears to be so obvious, I can’t understand how I could be the first to see it, so I must be missing something. Perhaps a later lecture by Fowler explains this pair of paradoxes.

My hypothesis appears to provide a solution to this paradox. That is, the inertial frame (comprised by the FLATCAR, the two light clocks, and the observer) somehow contains a medium within which light travels and which necessarily moves in synchronization with the inertial frame. Within this moving medium, light travels in any direction at the constant speed, “c”. Consequently, time does not need to slow down or speed up in the FLATCAR observer’s inertial frame, relative to the TRACKS observer’s inertial frame to for that to happen.

Still, a real puzzler to me in applying my hypothesis to this paradox is how a medium moving with its inertial frame can exist around the light clock mirrors on the FLATCAR. That is, the space between the mirrors is open. The spaceship in the example I used to explore my hypothesis is closed.

MICHELSON-MORLEY EXPERIMENTS:

My understanding of the results of the Michelson-Morley experiments is that they split a light beam into two beams, one at a right angle to the other. After traveling a significant distance, both beams arrived back at the starting point at the same time. Consequently, the speeds of the light beams were unaffected by an "aether", the direction of the earth’s rotation, the earth’s orbit around the sun, the sun’s movement within the galaxy and the galaxy’s movement away from the hypothesized big bang center. If light traveled a different speed depending on its direction relative to the earth’s rotation, etc., the two halves of the light beam in the Michelson-Morley experiments should have returned at different times. This result appears to support my hypothesis. The medium to which I refer is quite different from an "aether".


Allen W. McCready

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by kc3mx</i>
<br />As I understand you, you are saying that you found an experiment that claims that the earth's rotation can not be detected. There are experiments which have detected the rotation of the earth. The Michelson-Gale being the most famous. This means the velocity of light is different going east from going west. The Haefle-Keating experiment found that the time dilation of clocks was different going east versus going west. So the earth's rotation can be detected and this implies that light velocity is not the same for every direction on the earth.
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I will see what I can find on the Michelson-Gale and Haefle-Keating experiments. They weren't mentioned in the material I have covered to date.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Allen W. McCready</i>
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However, if a second, but identical, light clock added to the FLATCAR were aligned pointing toward one corner of the rear of the FLATCAR, then “d1” would be greater than “d2” for that second clock. That is, the receiving mirror would have moved closer to the first mirror while the light pulse was traveling. Using the same logic used for the first light clock, that would mean that time for the rearward pointing light clock and its observer on the FLATCAR would have to speed up proportionately, relative to the observer on the TRACKS.

Consequently, to the observer on the FLATCAR, time would have to slow to account for the first light clock, yet simultaneously speed up for the second light clock…a paradox.

Another paradox is that since this first paradox appears to be so obvious, I can’t understand how I could be the first to see it, so I must be missing something. Perhaps a later lecture by Fowler explains this pair of paradoxes.

My hypothesis appears to provide a solution to this paradox. That is, the inertial frame (comprised by the FLATCAR, the two light clocks, and the observer) somehow contains a medium within which light travels and which necessarily moves in synchronization with the inertial frame. Within this moving medium, light travels in any direction at the constant speed, “c”. Consequently, time does not need to slow down or speed up in the FLATCAR observer’s inertial frame, relative to the TRACKS observer’s inertial frame to for that to happen.

Still, a real puzzler to me in applying my hypothesis to this paradox is how a medium moving with its inertial frame can exist around the light clock mirrors on the FLATCAR. That is, the space between the mirrors is open. The spaceship in the example I used to explore my hypothesis is closed.

Allen W. McCready
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That’s like the difference between a moving airplane (with the sound medium sealed inside) and an open flatcar on a train (with the sound emitter moving through the air). In the airplane there is no “medium wind” but on the flatcar there is.

Consider the “flatcar” to be a whole planet, with the light-speed-regulating medium traveling through space with it. I think a real “flatcar” on earth would travel through the earth’s light medium. Note that in some illustrations of this thought experiment, a laser is aimed straight up when the flatcar is stationary on earth, but it is aimed toward the right when the flatcar is moving toward the right. It must be aimed toward the right because if it was not, the laser beam going straight up would miss the top mirror on the moving flatcar. With the laser beam aimed toward the right, of course it will take longer for the light beam to hit the moving mirror, but that doesn’t slow down time on the flatcar.