For more than a hundred years measurements of the
speed of light have been consistent... the speed
of light is c for all observers. Motion of matter
is always less than c.

What is the experimental basis of Special Relativity?
http://math.ucr.edu/home/baez/physic...periments.html

Physics is an experimental science, and as such the experimental basis for
any physical theory is extremely important. The relationship between
theory and experiments in modern science is a multi-edged sword:

1.It is required that the theory not be refuted by any experiment within
the theory's domain of applicability.
2.It is expected that the theory be confirmed by a number of
experiments which cover a significant fraction of the theory's
domain of applicability.
3.It is expected that the theory be confirmed by a number of
experiments which examine a significant fraction of the theory's
predictions.

Special Relativity (SR) meets all of these requirements and expectations.
There are literally hundreds of experiments which have tested SR, with
an enormous range and diversity, and the agreement between theory and
experiment is excellent. There is a lot of redundancy in these experimental
tests. There are also a lot of indirect tests of SR which are not included
here. This list of experiments is by no means complete!

Other than their sheer numbers, the most striking thing about these
experimental tests of SR is their remarkable breadth and diversity. An
important aspect of SR is its universality - it applies to all known physical
phenomena and not just to the electromagnetic phenomena it was
originally invented to explain. In these experiments you will find tests
using electromagnetic and nuclear measurements (including both strong
and weak interactions); gravitational tests are the province of General
Relativity, and are not considered here, see Experimental Tests of GR.

There are several useful surveys of the experimental basis of SR:

Y.Z.Zhang, Special Relativity and its Experimental Foundations,
World Scientific (1997).
G.Holton, "Resource Letter SRT-1 on Special Relativity Theory",
Am. J. Phys., 30 (1962), p462.
D.I.Blotkhintsev, "Basis for Special Relativity Theory Provided by
Experiments in High Energy Physics", Sov. Phys. Uspekhi, 9 (1966),
p405.
Newman et al. Phys. Rev. Lett. 40 no. 21 (1978), p1355.

Zhang's book is especially comprehensive.

Textbooks which have good summaries of the experimental basis of
relativity a

M.Born, Einstein's theory of Relativity.
Bergmann, Introduction to the Theory of Relativity.
Moller, The Theory of Relativity.
M. von Laue, Die relativitätstheorie (in German).

Crank Information
http://www.google.com/search?q=%22Ch...ww.cran k.net
http://groups.google.com/groups?q=gr...hor%3ASansbury