This line of discussion threatens to generate even another split thread. A hazard of attempting to use controversial positions in argument for an only tangentially associated discussion. Here Tach is technically correct in direct reference to the question he was answering. Both time dilation and length contraction are experimentally "observable". They are not both experimentally measureable or proven, in any direct sense. While clocks preserve the affects of time dilation, as they move between frames, the same is not true of rulers. In addition length contraction, within the context of high energy particle physics, is only observable as an interpretation of downstream data, and then.., only as that data is interpreted based on the underlying theory. But, again.., and as Pete has mentioned earlier, if this subject is to be pursued, it should be in a thread of its own.