In this article, we continue to expose the errors in Phillip Dennis’s attempt to overthrow the conventionality thesis of the physics of Einstein. We have already refuted Dennis’s antibiblical philosophy of presentism and shown it to be incompatible with relativistic physics and the Bible. Here we refute several more of Dennis’s errors in physics, but we begin with something that Dennis actually got right.
In this article we expose and refute some of Phillip Dennis’s mistakes in physics in his latest attempt to overthrow the conventionality thesis of relativity. Recall that the conventionality thesis is the position that the one-way speed of light is not a property of nature, but a stipulated convention by which a given observer judges whether two clocks separated by some distance are synchronized. I showed in my first refutation of Dennis that he had arbitrarily assumed the ESC convention in his attempt to establish the ESC convention over ASC (Lisle 2024). But this is the fallacy of begging the question. I also showed in this same paper that the conventionality thesis follows logically from the relativity of simultaneity (Lisle 2024).
We have been analyzing the claims of Phillip Dennis and his criticism of the ASC model. In particular, Dennis claims to have refuted the conventionality thesis – Einstein’s claim that the one-way speed of light “is in reality neither a supposition nor a hypothesis about the physical nature of light, but a stipulation which I can make of my own freewill in order to arrive at a definition of simultaneity” [emphasis in original] (Einstein 1916). Conversely, Dennis claims that Einstein is wrong and that the one-way speed of light is necessarily the same as the round-trip speed of light: c = 186,282.397 miles per second in vacuum. However, we have already shown that Dennis’s previous attempts to prove this were fallacious because they begged the question. That is, Dennis had used equations that tacitly assume the one-way speed of light. In his latest article, Dennis claims that the one-way speed of light has been empirically measured in two independent experiments. We will examine the first of these here. We will again show that Dennis has once again begged the question. That is, he unwittingly assumed the one-way speed of light is isotropic in his argument.
In this article, we review – at a layman level – the original argument that Phil Dennis made against ASC and my refutation of his claims. This is important for two reasons. First, Dennis’s first article contained a great deal of mathematics, and this required me to reply in kind. Therefore, my goal here is to explain the disagreement between us without using any equations so that the layman may understand the essence of the dispute.
Did Phillip Dennis actually disprove the conventionality thesis (Dennis 2024)? Did he really prove at long last what physicists over the last century have been unable to do – to establish that the one-way speed of light in any given direction must be the same as the round-trip speed of light? Did he find any genuine inconsistency with the Anisotropic Synchrony Convention (ASC) and the young universe model upon which it is based? Well, no to all of the above…. We show below that when the full synchrony-independent equations are used, they do not support Dennis’s conclusion but rather the opposite. Furthermore, we will demonstrate several critical errors in Dennis’s analysis and show that several of his claims are incompatible with the physics of relativity.