File:Stellar aberration versus the dragged aether.gif

English: Complete aether dragging can explain the negative outcome of all aether drift experiments such as the Michelson-Morley experiment). However, this theory is considered to be wrong for many reasons. One reason, is that complete aether dragging is inconsistent with the phenomenon of stellar aberration. Aberration occurs when the observer's velocity has a component that is perpendicular to the line traveled by the light incoming from the star. In this animation, imagine the stars to be infinitely far away. As seen in the animation on the left, the telescope must be tilted before the star will appear in the center of the eyepiece. If the aether drag hypothesis were true, then stellar aberration would not occur because the light would be travelling in the aether which would be moving along with the telescope. As seen in the animation on the right, if the aether is dragged in the vicinity of the earth, then the telescope must be pointed directly at the star for the star to appear in the center of the eyepiece.