This thread is a continuation of a discussion that began here: http://www.bautforum.com/showpost.ph...3&postcount=33

I contend thatallone-way speed measurements, including measurements of the one-way speed of light, arealwayscoordinate-system dependent measurements. I do not believe that this is really an ATM concept at all, but recognize that (at first glance) it could have theappearanceof being an ATM concept.

There are two completely separate issues here: 1) that the various "test theories" of special relativity are typically applied to guide the design of experiments that probe for violations of Lorentz symmetry, and 2) that the interpretation of any one-way speed measurement is always coordinate-system dependent. Although I am personally interested in designing experiments that probe for unique violations of Lorentz symmetry, whether or not any such violation exists is not the primary issuehere. For the purposes ofthis thread, we are only concerned with understanding the coordinate-system dependent (or otherwise) nature of one-way speed of light measurements.

Here are some of the relevant statements that I have already made on this subject within the parent thread:

"Special Relativity is just acoordinate systemin which the one-way speed of light isdefinedto be isotropic. This coordinate system (inertial reference system) is convenient in that it can be realized today in any laboratory. An alternate coordinate system in which the one-way speed of light is defined to be anisotropic is just as valid as SR (when both systems are properly specified: see Y.Z. Zhang,Special relativity and its experimental foundations, (1997); http://www.worldscibooks.com/physics/3180.html)." -- http://www.bautforum.com/showpost.ph...3&postcount=33

The speed of lightisn't a measurable quantitywithin an inertial reference system, it isdefinedas a constantc. -- http://www.bautforum.com/showpost.ph...3&postcount=20

The one-way "speed of light" isn't measurable in any coordinate-independent way whatsoever. There is no experimental basisat allfor supposing that the speed of light is a constant; such a statement is coordinate-system dependent. -- http://www.bautforum.com/showpost.ph...3&postcount=29

I referenced a text book in my first post that fully supports what I have said. Here's another well-known reference where you will find this quote on page 499: "When clocks are synchronized according to the Einstein procedure the equality of the velocity of light in two opposite directions is trivial and cannot be the subject of an experiment." -- R. Mansouri & R.U. Sexl,A test theory of special relativity: I. Simultaneity and clock synchronization, General Relativity and Gravitation, Vol. 8, No. 7 (1977). -- http://www.bautforum.com/showpost.ph...3&postcount=31