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 />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
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In their 1887 paper, here:

www.aip.org/history/gap/Michelson/Michelson.html#michelson1

Michelson and Morley said that they might need to conduct their experiment up on a high mountain to get up above and away from the earth’s local ether, which Stokes proposed the earth might carry with it as it moves through space.

<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>
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.
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Yes. And thanks for your response.

If superman punched a hole through the airplane from front to rear, the outside sound medium (air), traveling at a different velocity, mixes with the inside sound medium (air), distorting the transmission of sound within the aircraft, accordingly. So, it would help to know for sure exactly what light's range of medium(s) and method(s) is (are) and how they worked. However, that is pulling the horse with the cart.

I understand from Michael Fowler's lectures that light is generally regarded as something that can travel as waves through electromagnetic fields. Therefore those fields constitute at least one light-speed-regulating medium for light. Furthermore, I do understand that electric and magnetic fields are related. For example, I presume an electric generator uses magnetic fields to convert physical movement into electricity and an electric motor does the opposite.

I do not know whether gravitational fields are somehow similarly related to electromagnetic fields, or whether light can travel as waves (or photons) through gravitational fields or through other light-speed-regulating mediums.

I have not learned yet whether light can travel as other than waves, so perhaps photons are somehow part of or cause the light waves that travel through electromagnetic fields. Perhaps light can also travel as just photons through empty space/time. However, that would seem to make the seemingly empty fabric of space/time a light-speed-regulating medium. Light can obviously move through objects, e.g., air, glass, water, etc. However, in addition to light-speed-regulating mediums that allow light to move or make it move at the constant speed c, there may also be mediums that simply impede light. For example, perhaps gasoline may be considered a medium that enables a car’s driver to get a speeding ticket, but, sugar or water may then be considered mediums that simply interfere with the driver’s pursuit of a speeding ticket. As you can see, I can only wildly speculate.

<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>
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.
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It is certainly true that compared to a thought experiment involving a spaceship, the planet earth would be a spaceship with its occupants and structures on its hull. A railroad flatcar would be similar in that respect to spaceship earth, and, spaceship earth is moving through the contents of space/time by rotating, orbiting the sun, etc.

That analogy makes me entertain the possibility that light-speed-regulating mediums, should they really exist, have some RULES OF PRECEDENCE, as well as some RULES OF ENCAPSULATION, and perhaps some RULES OF APPLICABILITY.

By RULES OF APPLICABILITY, I mean that some mediums may enable light to travel, some may regulate light speed, and some may simply interfere with or impede light travel. (See my sick speeding ticket analogy, above.) There may be other categories, as well. I believe Michal Fowler’s lectures say that the Michelson-Morley experiments around 1930 at the Irvine ranch in California were intended to prove that an “aether” existed, which would slow light down, depending on light’s direction relative to any directional movement of that aether. That is, light would have to “plow” through that aether, so that aether would not be an enabler or regulator, but rather an impeder. However, the experimental results show that since the speed of light was constant in two directions that were 90 degrees apart, there must not be an "aether", or if there is, then it did not affect the speed of light.

By RULES OF PRECEDENCE, I mean the "strength" or "density" of one medium versus another. Does light simply travel through the strongest medium, the one with the greatest velocity, some combination, or none of the above?

By RULES OF ENCAPSULATION, I mean whether or not a particular light-speed-regulating medium for a particular moving inertial frame can be separated from the medium in a surrounding inertial frame. The hull of an aircraft is an effective encapsulator for sound's medium (air). The hull of a spacecraft blocks light (unless it is transparent), but does it block light's speed-regulating-medium? Even if we knew with certainty that the speed of light (generated and received anywhere within and only within a spacecraft traveling at light significant speeds) was the constant "c", that doesn't necessarily mean that the hull directly encapsulated the medium and separated it from the surrounding inertial frame, so that within the capsule, the medium assumed the inertia of the spacecraft’s inertial frame. Instead, the inertia of the hull, rather than the hull, may somehow more directly delimit or impart matching inertia to the electromagnetic, gravitational, or whatever field(s) that comprise the light-speed-regulating-enabling medium within the hull. This reminds me of debates as to whether cold moves into a house, or heat leaves it, or whether the vacuum created above an airplane’s wings lifts the wing or the air striking the front and bottom of the wing pushes the wing upward.

Considering my pompous rules, and your great spaceship earth analogy it seems logical and likely to me too that the medium between light clock mirrors in the FLATCAR thought experiment would be external, that is, the earth's surrounding medium, as opposed to an internal "inertial medium" moving with the FLATCAR. Light's behavior with respect to pions (as I understand it) supports that scenario, because as soon as the pion emits light, that light travels only at speed "c", not "c" plus the velocity of the emitting pion. However, if I understand it correctly, the theory of relativity would say that time slows enough on the FLATCAR, because of its relative inertia/velocity to make the speed of light generated on the FLATCAR equal to "c", regardless of the light's direction. If the speed were indeed empirically proven to be "c", then in terms of "inertial" mediums, the medium would somehow necessarily have inertia matching the FLATCAR's, not that of the earth's, regardless of whether relativity or medium theory or both were correct.

However, spaceship earth as a thought experiment has some things going for it that the FLATCAR doesn't, e.g., its relative mass, size, etc.

<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>
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.
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I am not sure what you mean by the laser beam being aimed to the right if the flatcar is moving to the right. Do you mean perpendicular to the length of the FLATCAR and horizontal?

In an interior room in the bowels of a very fast cruise ship (instead of a FLATCAR), the trajectory of a ping pong ball (instead of a light pulse) in any direction should be unaffected by the ship’s velocity. That is because the ball shares the same forward momentum as the mirror and the ball is unobstructed by interfering winds, seagulls, or UFOs from the outside. Similarly, it would seem that a light pulse emitted toward an overhead mirror would still reach the mirror, even though the mirror was obviously moving forward while the light was traveling. If a light-speed-regulating medium existed in the room and had inertia equivalent to the inertial frame established by the room, the emitted light should assume the medium’s inertia (which matches the mirror’s inertia) and arrive safely at the moving overhead mirror. I believe the theory of relativity also dictates that the light reaches the overhead mirror, since the local observer’s perspective, e.g., the alignment between the light emitter and the mirror, necessarily remains intact, as though the room were not moving.

However, if the light-speed-regulating medium was instead that of the surrounding inertial frame (the ocean), then depending on the room’s velocity, the overhead mirror could move enough to miss the light pulse. Furthermore, due to the earth’s mass, size, etc., a precedence rule may apply. That is, instead of the inertia of the light-speed-regulating medium being that of the room’s inertial frame, the earth’s inertial frame may somehow dominate. I think this is what you are saying.

In contrast, on a FLATBED RAILROAD CAR, the ping pong ball’s trajectory would be substantially affected by the intrusion of outside air. However, a light beam should not be materially affected by that air intrusion. Since the distance from the light emitter to the mirror is not enclosed, then any light-speed-regulating inertial medium would appear to be that of the surrounding inertial frame, not that of the FLATCAR. As a result, an emitted light pulse may not reach an overhead moving mirror. Again, if I understood you correctly, I think this is what you are saying. However, my understanding is that the theory of relativity dictates that the emitted light reaches the moving mirror, even though the intervening distance is open.

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 DAVID</i>
<br /><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 />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
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In their 1887 paper, here:

www.aip.org/history/gap/Michelson/Michelson.html#michelson1

Michelson and Morley said that they might need to conduct their experiment up on a high mountain to get up above and away from the earth’s local ether, which Stokes proposed the earth might carry with it as it moves through space.

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Thanks for your response. I will check that paper out.

My currrent understanding from Michael Fowler's lectures is that the earlier experiments around that timeframe (1887) were to empirically determine the speed of light. Since the experimenters thought an aether would interfere with those measurements, they moved their experiment to some mountain tops. Although the Irvine ranch experiments around 1930 also produced a speed of light, that was a byproduct. Allegedly, the later experiments were intended to prove that an aether existed by hopefully showing that the two halves of a light beam split into two halves traveling at right angles to one another would arrive back at their origin, after being reflected by distant mirrors, at different times. Instead the two halves arrived back at the same time, allegedly proving that no light speed impeding aether existed or it didn't impede light speed. According to Fowler, some experts feel that the earlier mountain top experiments more accurately calculated the speed of light.

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 Allen W. McCready</i>
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I have not learned yet whether light can travel as other than waves, so perhaps photons are somehow part of or cause the light waves that travel through electromagnetic fields. Perhaps light can also travel as just photons through empty space/time<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Regarding a photon as a “particle”, my opinion is this:

As best as I can figure out, light is not “particles” at all, but only electric and magnetic “waves”. A single photon is some kind of “wave packet” consisting of one or more wave set or group, perhaps as few as just one complete wave cycle.

The wave “packet” of visible light seems to be a long little thing, longer than it is wide, maybe something like a wiggling electric and magnetic field (very small, tiny, short, and not very wide) pair, traveling through space very fast.

Neither Planck nor Einstein called it a “particle” in their original “quantum” articles. The referred to it as something like oscillating fields emitted from wiggling atoms they called “resonators”.

The idea that a photon was a “particle” came later when the quantum mechanics guys started trying to say that everything is made up of individual “particles”.

So, even though photons are (in my opinion) waves only, when the two fields hit something they have an impact on the fields of the objects that they hit, so this is how light “acts like a particle”.

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Regarding the light clock, here is a link to a crude drawing of a laser beam light clock.

users.powernet.co.uk/bearsoft/LtClk.html

Note that when the top mirror is moving, they show the light coming out of the laser at an angle, and going up toward the right. This is an incorrect illustration. On earth, a laser aimed straight up will not send light out to the right just to conform to a thought experiment. A real laser would have to be aimed toward the right to hit the moving mirror. The light travels farther to hit the moving mirror, but time has not slowed down for either the laser or the mirror.

Now, if we mount the mirror rigidly over the laser and consider that both the laser and the mirror are moving through space, but not relative to the earth’s surface, then we must realize that the earth is carrying some kind of “medium” along with it so the light can go straight up and not be “blown” off to the side by some kind of “ether wind”. So, where ever the earth moves in space, the light beam moves sideways with it so that it will always hit a mirror that is mounted rigidly over the laser. This indicates an “ether” or “medium” that is fixed with the earth and moving through space with it.

Here is a link to a report about a meeting on the Michelson-Morley experiment held in 1927:

adsbit.harvard.edu/cgi-bin/nph-iarticle_...?1928ApJ....68..341M

<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>
<br />Here is a link to a report about a meeting on the Michelson-Morley experiment held in 1927:

adsbit.harvard.edu/cgi-bin/nph-iarticle_...?1928ApJ....68..341M

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Thanks. I will check it out and compare it with Michael Fowler's lectures that I just recently read and from which I got most of my understanding.

Allen W. McCready