In 2001 Jason Lisle (under the pen name Robert Newton) introduced the idea of Anisotropic Synchrony Convention (ASC) into the discussion amongst biblical creationists to solve the starlight travel time problem. For full understanding of those issues read here, here and/or watch this. With that came the notion of the one-way speed of light. Many people, creationists included, have since expressed disbelief, concern, and other emotions over the concept, but what is important to say at this point is that it is based on real physics. The point is that the one-way speed of light cannot be measured and as a result it really has no physical meaning in the universe. And this might sound crazy, but as a result, we are free to choose its value. In the ASC model, proposed by Lisle, and supported by myself, the incoming speed of light is chosen as infinite and the outgoing speed as ½ c (where c ≡ 299 792 458 m/s is the canonical speed of light that we are nowadays familiar with).
I note that at the 2018 International Conference on Creationism (ICC) two papers were presented that largely boil down to the same model that Lisle originally presented. Those papers are
- T.G. Tenev, J. Baumgardner, M.F. Horstemeyer, A solution for the distant starlight problem using Creation Time Coordinates. (PDF available here)
- P.W. Dennis, Consistent young earth relativistic cosmology (PDF available here)
This is all quite significant because, since 2001, I have largely supported the ideas that Dr Lisle has presented. Others within the creationist community have ridiculed them. Personally I now take the position that a biblical creationist model based on the ASC or at least the concept of defining an initial creation scenario which involves the ASC or a variant of that, such as Tenev et al have suggested in their paper, is the best solution to the creationist starlight travel time problem. In such a case, there is no problem.
Many months ago I received a paper wherein the authors attempted to show that the one-way speed of light could be measured by an experiment sending a light signal around a ring bouncing it off a few mirrors. (See the figure to the right) But any such experimenter who thinks it does that assumes the conclusion (begs the question) by not properly understanding the physics and the underlying assumptions of such an experiment. There are components (relative to the Source measured at the Timer) of outbound and inbound light vectors that must be considered. So no such experiment is ever only one way, it is always two-way, and as such it can never measure the one-way speed of light. (Besides the ASC is a convention, it is not something that can be refuted. We use a convention to define the basis under which we make a measurement, not the reverse.)
The authors of the same paper(s) also must have sent it to Dr Lisle for a review. He sent me his response to their paper(s) and I publish it below with his permission.