A History of the Aether in Physical Theory: Part IV
Summary of this page:

  • The Lorentz-Fitzgerald equations seeks to explain the null result of Michelson-Morley experiment
  • The Lorentz-Fitzgerald length-contraction.
  • Lorentz Electron Theory (Aether and Matter as Separate)
  • Einstein: His Special Theory of Relativity, Explanation of the photoelectric effect and General Theory of Relativity.
Lorentz-Fitzgerald
Length Contraction: Distortion of Objects Moving Through the Aether
Lorentz and Fitzgerald hypothesized that the motion of the aether was undetectable because, as an
object moves through it, the object contracts or changes shape. All matter would be affected as it
traveled through the aether. They argued that the M-M experiment produced a null result because the
measuring apparatus contracted in length in the direction of travel. The light emitted from the source of
the apparatus was affected by its travel through the aether as predicted (higher speed for light the earth
is moving towards), but so was the apparatus itself, cancelling out any difference when the speed of light
was measured by the detector.
Einstein
Animation of "length contraction" or more correctly, shape distortion
If the length contraction of matter moving through space is verified to be true, this
would seem to necessitate the existence of an aether, for its length contraction would
otherwise be inexplicably caused.

However, as I will explain next, Einstein assumed that the length contraction of an
object in motion is actually a relativistic phenomenon. This means that there is no
physical contracting occurring, but rather that, the
appearance of contraction is relative
to the observer, and how fast or slow he or she is moving while observing the moving
object.

The last page of the
Atoms section describes how, using the revised aether theory, the
Lorentz length contraction is a real, not just relativistic phenomenon.
Einstein, in his Special Theory of Relativity, was able to derive the same length-contraction equations as
Lorentz-Fitzgerald, without the need to hypothesize the existence of an ether at all. In opposition to
Lorentz' conception, which understood the length contraction of objects to be a material and actual
phenomenon, length contraction, according to STR, it is an entirely relative, not real, phenomenon. STR
states that it depends entirely on the discrepancy of speed between inertial frames—that is, the
discrepancy between the inertial frame, or uniform and linear speeds, of the moving apparently length-
contracted objects, and the observer of that object.


       Furthermore, STR rejected the need for a single universal frame of reference, the movement or non-
movement of the ether, since all frames of reference were deemed relative to the frame of reference of
the observer. He justified this claim based on the assumption that the speed of light is constant in all
inertial frames of reference, not just the stationary one from Maxwell derived it. Based on this assumption
of “c”, and the relativity of all inertial frames, Einstein concluded that the concept of a position in space or
time was not absolute—could be given by a set of exact coordinates—but could differ depending on the
observer's location and velocity. For Einstein, while everything else in the universe is relative, without
absolute positions in space or time, somehow light is not relative, and always retains its invariant speed,
c. The fundamental and fatal flaw of STR, however, has to do with this latter assumption—that the speed
of light is constant in all inertial frames. Without empirical proof that the speed of light is in fact constant,
STR, and his General Theory of Relativity fall, which allows the tentative reinstatement of the ether as
viable physical theory (for example, to explain Lorentz' length contraction).
To explain the photoelectric effect, Einstein hypothesized that light must be a particle (photon) to transfer
energy to electrons discontinuously. From the time of Newton, the ether had only been hypothesized to
exist as a medium for the transmission of light waves; however, with Einstein's seemingly successful
photon-theory of light such a medium no longer seemed needful. Furthermore, Compton later provided
experimental proof that photons have particle-like properties because of the way they collide with
electrons.


       Nonetheless, light undeniably exhibits many wave-like properties, as clearly shown in the double-slit
experiment. It seemed inescapable, then, that light be considered to be have dualistic nature—that it be
considered to be both a transverse wave (of emptiness) and particle at the same time. Aside from
violating the principle of excluded middle, which states that a thing must be predicated of one or another
of two mutually exclusive predicates (in this case a wave or a particle)—predicates whose combination in
a single object would result in an inadmissible logical contradiction—aside from this transgression of logic,
the transverse wave half of the wave/particle duality of light presented problems of itself. Without an
ether, it was inconceivable to imagine of what exactly the wave-half of the wave/particle duality was a
wave. If a wave is, by its very definition, a disturbance of a materiate medium, what kind of medium can
an empty etherless space be? Furthermore, how could the wave be transverse if by its very definition, it
is propagated by the motion of particles perpendicular to the direction of movement of the wave? Einstein
said we have to take it for granted that space has this physical property to transmit light waves. But it is
even more inexplicable to claim that the “fabric” of space consists of “electromagnetic fields” somehow
“activated” by a light particle-wave than it is to claim that light propagates through an ether more dense
than steel, and with “restoring forces”. An EM wave cannot propagate in a matterless vacuum.
       The current concept of light, then, with the total rejection of the ether, is a photon-wave duality
whereby the transverse wave-half of the duality is somehow transmitted via the “vacuum materiate.”
Einstein's Explanation of Photoelectric Effect
The General Theory of Relativity
Ironically, Einstein revised his position on the existence of the aether.
This is quoted from thelast paragraph of Einstein's "Ether and the Theory of Relativity"
Recapitulating, we may say that according to the general theory of relativity space is endowed with physical qualities; in this
sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in
such space there not only wonld be no propagation of light, but also no possibility of existence for standards of space and
time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this ether may not be
thought of as endowed with the quality characteristic of ponderable media, as consisting of parts which may be tracked
through time. The idea of motion may not be applied to it.
It is unnecessary to go into any detail of the General Theory of Relativity. It was proposed by Einstein to explain the
phenomenon of gravity. Einstein postulated that space is actually a pure gravitational field activated by matter. This
means space is affected by, and in turn affects, the motion of matter. This affect is geometrical in nature: bodies and
their velocities warp or curve space. Massive bodies curve space so much that, with no expenditure of energy, and with
the presence of no force, bodies in their orbits follow the path of curvature; that is, move curvilinearly. Even light-rays
that pass by a massive bodies do not travel in straight lines; the gravitational field—the curved space—bends them. In
addition to curving space, the matter-activated gravitational field of massive body is equivalent to an accelerated inertial
frame. This means that, when a smaller body is close enough to the massive body's surface, it accelerates towards it. In
short, it is described thus “Matter tells space how to curve, and space tells matter how to move” (J. Wheeler).
The blue lines drawn here are used to help
one imagine "bending" space. The bending
occurs in the "4th dimension" of space-time.
This bending is postulated to cause the
bending of a light-ray (in this case a signal
from a satellite near Saturn) as it passes the
sun  and makes its way towards earth.
Very Brief Summary of Aether Theory
State of Modern Physics
Against the General Theory of Relativity
(and dimensions beyond 3)
  • Matter does not "bend" space. It is not
    this "bending" that causes orbital
    motion. Einstein misused the
    mathematics of dimensions when he
    supposed there are four dimensions.
  • Click Here for a video that debunks
    Einstein's space-time (four dimensions)
Click Here for a description of Einstein's explanation of the photoelectric effect.

Click
Here for a description of the two-slit experiment which proves light is "also" a wave.
The Immobile Aether Distinct From Matter
Lorentz' electron theory, however, developed in the 1890s, is based on the hypothesis of a totally
immobile ether. Lorentz built his theory upon a strict separation between ether and matter. In his view,
the only way in which the two can interact is through tiny charged particles—first called ‘ions’ and later
‘electrons’ and assumed to be present in large quantities in all matter—which generate electric and
magnetic fields in the ether. These fields in turn exert forces on the charged particles.