[wisp]

Einstein's relativity has become so established in modern science that it is being taught as if it were a religious belief.
Those who challenge his theories are written off as cranks. However, there is a distinct lack of evidence to prove that his relativity theories are wholly correct.
A simple way to test the "principle of relativity - the speed of light is constant ..." is to carry out "one-way" speed of light tests.

No one has done a simple one-way test using two clocks and a laser, to measure the speed of light.

Why?

[wisp]

However, not everyone believes in this religious instruction, see:
Einstein’s fallacies
"Einstein’s relativity theory is a central plank of 20th-century science and is commonly said to have passed every experimental test with flying colours. However, there are plausible alternative explanations for all the experimental data and astronomical observations currently cited in support of the special and general theories of relativity, and the internal inconsistencies and unwarranted assumptions of standard relativity theory have been pointed out by dozens of scientists".
http://ourworld.compuserve.com/homep...p5/relativ.htm