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How
the Aether Was Repeatedly Abandoned
by Sid Deutsch It is
appropriate for the purpose of this Essay to repeat the following: A
ray of light is a beam of photons, an electromagnetic wave. It can
propagate for billions of years through the vastness of the Universe,
at a velocity of 3 X 108 m/s, independent of photon
frequency, and without an iota of attenuation, until it is absorbed by
a material object. There is no way this is possible without an
all-pervading aether carrier. The aether is most peculiar and special
in that it can carry a photon wave motion, which includes an amount of
energy equal to E = hf, without the frictional loss
that characterizes a sound wave.
(Spelling note: Throughout this essay, aether is used rather than ether.) From my perspective, here is what the Universe looks like: It is occupied by relatively stationary aether particles, which define the Universe. Here and there in this huge ocean of particles, like droplets in a fog, are minuscule atomic nuclei, mostly protons. At relatively large distances, like planets around the sun, we have electrons orbiting the nuclei. So the Universe consists of “aether” space with small interlopers, material objects such as electrons, atoms, planets, and stars. These move about at a relatively slow pace compared to the speed of light. For example: the movement of the earth around the sun is at a speed 0.01% that of the speed of light. As it moves, each material object causes slight turbulence in the ocean of aether particles. Some of the above is depicted in Fig. 1, which shows the earth (US) and a second planet that is moving to the right (THEM). In accordance with Einstein’s special relativity, the velocity of light on each planet is 3 X 108 m/s; this is accomplished by having an aether “atmosphere” surround each planet, held in place by gravity exactly as our air atmosphere (and"Dark Matter"?) has been captured. Between the planets is the aether “background,” shown slowly drifting to the north in Fig. 1.  In Fig. 1(a), a ray of light is shown traveling from earth to the second planet. The conventional view is that, if there is an aether, the ray has to bend, as shown, when it crosses an aether motion discontinuity. Because this bending is not observed, the model is revised, in Fig. 1(b), to portray the ray as following a straight-line locus. The rationale behind the non-bending model is that aether particles are “out of this world”: They are frictionless, too small for us to be able to measure (thus far), and they propagate transverse electromagnetic waves at lightning speed. There is every reason for them to act differently from the carriers of longitudinal sound waves. (Electromagnetic rays do bend when undergoing a change in velocity, such as from air to glass.) So the aether particles don’t bend light because light doesn’t change its speed in going from the earth’s aether “atmosphere” to the interplanetary aether “background.” Because the aether is a necessity and not a conjecture, heroic efforts were required, starting in 1905, to justify the abandonment of the aether. It is especially interesting to see how the textbooks, charged with conveying the truth to their inquisitive and sometimes skeptical audiences, weighed “the facts in the case.” Not a single one of them suggested that, in the strange and elusive world of the aether particle, it was possible for an electromagnetic field to propagate across an aether motion discontinuity in a straight line, without bending, as in Fig. 1(b), and that this is why it is so difficult to detect the aether. What was it like to be alive in 1905? Peter Galison’s entire book, “Einstein’s Clocks, Poincaré’s Maps,” (Norton, 2003) describes this fascinating period. Albert Einstein (1879-1955) was 26. Henri Poincaré (1854-1912) was 51. Hendrik A. Lorentz (1853-1928) was 52. In Galison’s index there are 26 page references to “Aether--Einstein’s rejection of.” The same thought repeated 26 times can get very boring, but Galison is too skilled a writer to let that happen. In the caption that describes the Michelson-Morley (M-M) apparatus, Galison neatly sums it up with (p. 204): - - - - - - - - - -
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Next,
jump ahead 50 years, to 1955, when Wolfgang K.H. Panofsky and Melba
Phillips very thoroughly examined aether theories in their book,
“Classical Electricity and Magnetism” (Addison-Wesley). (A
human-interest note-- Melba Phillips died on 8 November 2004 at the age
of 97.) On p. 240 is a Table that compares three aether theories and
special relativity (without an aether) versus 13 experimental outcomes
(including M-M experiments). One of the aether theories is called
“aether attached to ponderable bodies,” which is the theory promoted in
the present essay. On pp. 236-7 we have
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“Aether drag.” A further
alternative in which the concept of the aether could be reconciled with
the Michelson-Morley result was to consider the aether frame attached
to ponderable bodies. This would automatically give a null result for
terrestrial interferometer experiments. The assumption of a local
aether, however, is in direct contradiction to two well-established
phenomena.
The first is the aberration of “fixed” stars. Due to the motion of the earth about the sun, distant stars appear to move in orbits approximately 41" in angular diameter. Consider a star at the zenith of the ecliptic. If this star is to be observed through a telescope the telescope tube must be tilted toward the direction of the earth’s motion by an angle α, as shown in … . It is seen from the figure that, classically, tan α = v/c, and with 30 km/sec for the velocity of the earth in its orbit, α =10-4 = 20.5", in agreement with observation. If the aether were dragged by the earth in its motion we should expect no aberration to occur. - - - - - - - - - -
The model
of Fig. 1(a) fails the stellar aberration test, which I claim is
explained by the straight-line photon locus of Fig. 1(b). The model of
Fig. 1(b) also explains the second phenomenon mentioned above, which is
too technical to repeat here. Panofsky and Phillips conclude that “The
existence of an aether, either stationary or carried convectively, is
undemonstrable.”
Consider next an entire book devoted to Einstein’s special relativity: “Space and Time in Special Relativity,” by N. David Mermin (McGraw-Hill, 1968). On page 13 we have - - - - - - - - - -
In
essence, the famous Michelson-Morley experiment was an attempt to
measure [the] directional dependence of the speed of light with respect
to the Earth and thus to determine the speed of the Earth with respect
to the aether. The result of their experiment was that the speed of
light with respect to the Earth has the same value c whatever the direction of motion
of the light.
One might try to explain this by saying that the speed of the Earth with respect to the aether must be zero. Aside from the fact that this would be a rather strange coincidence, this explanation will not do. The Earth moves in its orbit around the Sun at about 30 kilometers per second. If the velocity of the Earth with respect to the aether happened to be zero at one time of year, then 6 months later when the Earth was moving at the same speed but in the opposite direction, its speed with respect to the aether would have to be 60 kilometers per second. In general, because of the Earth’s motion around the Sun, whatever the speed of the Earth with respect to the aether might be, this speed should vary through a range of speeds differing by up to 60 kilometers per second, throughout the course of a year. However experiments have shown that the speed of light with respect to the Earth is independent of direction, whatever the time of year. Thus if the aether does exist, it must be managing in a most mysterious way to escape our efforts to detect it. As Einstein showed, the way out of this dilemma is to deny the existence of the aether and face courageously the fact that light moves with a speed c with respect to any inertial observer whatsoever, regardless of the velocity of that observer with respect to any other observer (and, as a special case of this, regardless of the velocity of the source emitting the light). - - - - - - - - - -
My
comment is that the aether moves with
the earth [and with every massive (ponderable) object], much as the
atmosphere of air moves with the earth. And it does not take any
courage to believe that the speed of light, on a planet (or any massive
object) moving away from (or towards) the earth, is 3 X 108
m/s relative to that planet,
such as the one in Fig. 1.
Closer to our own time, let’s look at the 1994 book, “Space, Time and Quanta,” by Robert Mills (Freeman). On p. 17 he has - - - - - - - - - -
The big issue at the time [1905]
was the motion of the earth relative to the aether, the supposed material
substance thought to fill all of space and to act as a medium for the
propagation of light, analogous to the role of air with sound waves.
Experiments such as Michelson and Morley’s were known as aether-drift
experiments and were interpreted, though with severe difficulties, as
indicating that the aether is dragged along with the earth. The concept
of an aether was buried by Einstein (it was already pretty sick by
then), and I shall not discuss its history any further here. As we now
understand, EM [electromagnetic] waves require no medium, and they
exist and propagate even in completely empty space.
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Finally,
we expect the “McGraw-Hill Encyclopedia of Physics” (second edition,
1993) to reveal the life, and perhaps death, struggle of the aether.
Alas, it is not a history book. On p. 392 we have three short
paragraphs, by William R. Smythe:
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Aether hypothesis
James Clerk Maxwell and his contemporaries in the nineteenth century found it inconceivable that a wave motion should propagate in empty space. They therefore postulated a medium, which they called the aether, that filled all space and transmitted electromagnetic vibrations. During the last half of the nineteenth century, dozens of models were tried, but all broke down at some point. Direct experimental attempts to establish the existence of an absolute aether frame of reference, in which Maxwell’s equations hold and light has the velocity c, have failed. The best known of these is the Michelson-Morley experiment, in which an attempt was made to measure the velocity of the Earth relative to the aether. Every hypothesis (aether drag, Lorentz contraction, and so on) invented to reconcile some experiment with the aether concept has been disproved by some other experiment. At present, there is no evidence whatever that the aether exists. - - - - - - - - - -
My
comment is that in Einstein’s special relativity, the physical evidence
that the planet carries an “atmosphere” of aether, as in Fig. 1, is
that the velocity of light on the planet is c regardless of the speed
with which the planet is flying away (or toward) the earth.
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