Abstract
      Physical causes for the observed constant speed of light, inertia, and other perplexing phenomena are shown to be consequences of a quantum medium or ether through which photons are propagated at the speed of light. As a consequence of this medium, the speeds of light and the rates of energy exchange within an inertial reference frame depend on the velocity of the reference frame through the medium. Further, the standards of time, distance, and mass within the reference frame are affected by its velocity through the medium, a fact that has not previously been apparent. The medium exactly accounts for observed "relativistic" phenomena and the inability of many experiments to detect the medium. Evidence of this quantum medium is provided, and means for measuring the velocity of a reference frame or solar system through the medium are discussed. The effects of motion through the medium explain why observers in different inertial reference frames disagree on the rates of clocks, the lengths of bodies, and the times and locations of events. This disagreement is inherent in relativity theory, and it is unnecessary. When the physical effects of a system's motion through the medium are taken into consideration, observers in all inertial reference frames are in complete agreement on which clocks are running slower, which measuring rods are shorter, and which bodies are more massive. The observers agree on absolute standards of distance, time and mass, and nature appears the same to all observers, regardless of the velocities of their reference frames.

Consequences of the quantum medium which help understand this document.
(Note: If figures A and B do not have moving dots, try enabling your browser's "animations" option or try disabling your browser's "accelerator" which may show only one frame of animations. If you cannot get figures A and B animated, skip this web page because the moving dots are needed for understanding the text.)

      Let 5 spaceships be located in a region of the universe far from any concentration of matter. Exhibit A shows the 5 ships (black rectangles) in a "diamond formation" at rest relative to the quantum medium (represented by gray + marks). Light signals (gray dots), which are sent and received by the ships, are propagated at a constant speed through the medium.
     The light signals are used to maintain 1 light-second separations between the center ship and the other ships. The center ship sends a light signal to each of the other 4 ships every second, and the return signals from the 4 ships are received by the center ship 2 seconds later. If any of the round-trip signals takes more or less than 2 seconds, the ships adjust their spacing so that the round-trip signal time is 2 seconds.

      Now let the spaceship diamond formation change its velocity. Exhibit B shows it moving through the medium with a velocity of .8 times the speed of light. The diamond formation is foreshortened to .6 times its length in A to maintain the observed 2 seconds per round trip rate of photon exchange between the ships. Observers aboard the spaceships cannot detect the foreshortening or other changes from A to B.

     Photons moving between the center ship and the forward ship are moving at only .2 times the speed of light relative to the ships and take 3 seconds to traverse the .6 light-second distance between the ships. These photons (blue dots) are Doppler blueshifted. The photons comprising the return signal (red dots) are redshifted. These photons are moving at 1.8 times the speed of light relative to the ships and they take only .333 seconds to traverse the distance between the ships. Therefore, the round-trip signal time is 3.333 seconds. The round-trip signals to the other ships also take 3.333 seconds. (Signals in the transverse direction are moving at .6 times the speed of light relative to the ships because the photons must also have a component of their velocity through the medium be in the direction of the ships' motion through the medium, and this component must be .8 times the photons' speed through the medium.) The 3.333 second time duration for the round-trip light signals appears to observers in the diamond formation to be 2 seconds.

     The standards of time, distance, and mass in the diamond formation have changed in B, but observers aboard the ships are not aware of the changes. The observers and their instruments for measuring time, distance, and mass are affected by their motion through the medium, just as the diamond formation is affected by the motion and resulting decrease in rate of round-trip energy exchange. In B the pattern of the energy moving between the ships (and within the ships) is unbalanced. More energy is moving in the direction of the diamond formation's motion through the medium than in the opposite direction. Although observers in the diamond formation cannot directly measure the energy imbalance and the blue and red shifts of the photons, they are aware of their change in velocity and the work done by the spaceships' engines. This work was needed to change the balance of the energy moving within the diamond formation (most of which is within the atoms of the spaceships).
     The consequences of the medium will become clearer as the reader progresses through the following pages which discuss phenomena previewed in exhibits A and B.