Starlight aberration and Michelson-Morley's experiments (MMX) are considered to provide the most important information about the possible existence of an ether. However, logical weaknesses exist in both these methods. Fortunately, there exist alternative methods (based on one-way light propagation) that are useful. These methods indicate that the ether is entrained by the Earth's translation but not by its rotation. This ether can be united with starlight aberration.

This paper is aka "The Ether-Wind Problem and GPS"

The two main pillars in the foundation for the special relativity theory are given alternative interpretations. Starlight aberration, as well as Michelson-Morley-s experiments, is thereby demonstrated to be wrong and useless. A new interpretation is also given to the Sagnac effect, and this produces evidence for entrained ether. The existence of ether is found to be very helpful when we want to describe different phenomena in physics.

It is demonstrated that misinterpretations of stellar aberration and Sagnac effect has given false arguments against the entrained ether.

Special relativity (SRT) rests upon mainly two phenomena: stellar aberration and Michelson-Morley's experiment (MMX). Both phenomena appears to be interpreted mainly in the particle model for light. An alternative interpretation, based on the wave model including the property of transverse waves to conserve orientation in relation to changes in the ether-wind, is done. This renders both phenomena as silent in relation to the ether's state of motion. Since Sagnac effect is caused by translational motion, the effect on a rotating circle is the same as on a straight line in translational motion. This fact means that the effect is easily described, and that Sagnac effect in GPS (Global Positioning System) can give information about the ether's state of motion. A conflict between stellar aberration and entrained ether is here found to be wrong. An other conflict between entrained translation and not entrained rotation is given a possible explanation, which is of interest although not a proof.

By applying Stokes' rule the derivation of Sagnac effect can be changed from an integration over a surface to an integration along a line, which is correct in relation to where the light really is. This demonstrates that Sagnac effect is translational, and that an ether-wind has been detected by Sagnac and by the GPS system. Stellar aberration is demonstrated to be silent, since wave-fronts' orientations are conserved in changing ether-wind.