The theory of relativity (RT) is inconsistent: two twins, re-meeting after separation, will each be younger than the other. Nevertheless, the RT is widely accepted, mainly because of the experimental evidence. An analysis of the evidence, however, reveals that the experimental evidence is for E = mc2, but not for the notion of relativity. The Sagnac effect is even contrary to the RT. In this case RT can only be saved by the use of a Galilean transformation instead of a Lorentz transformation, and this is impermissible in a four-dimensional space-time. As it is the notion of relativity itself that causes the problem, there is no reason to stick to four-dimensional space-time. Instead, the freedom to choose space and time, which Einstein propagated, will be used to choose the old system: three-dimensional space and one-dimensional time, without the conceptions of absolute space and absolute time. A new theory can probably be developed, using Stokes?s idea of a compressible, irrotational ether, without his idea of a mechanical ether, but with an ether without mass.
