Is Einstein's theory of relativity able of solving the twin paradox?  When the traveling twin turns around to reach Earth, it observes a blueshift of the light emitted by Earth instantaneously, not after some time. This seems to suggest that the blueshift arises from the twin's own acceleration and therefore its own motion through ether, not from the apparent movement of Earth relative to it. The Earth, on the other hand, must wait for the blueshifted light from the traveling twin to reach it at