Feedback archiveFeedback 2012

Anisotropy Synchrony Convention

Different one-way speeds of lights

12 May 2012, Updated 16 Jun 2021

This week’s feedback addresses the solution to the distant starlight problem by astrophysicist Dr Jason Lisle, founder of Biblical Science Institute (of AiG at when first published, then of ICR—Ed.), the Anisotropy Synchrony Convention (ASC). CMI’s Dr Jonathan Sarfati, responds.

ESA/Herschel/PACS/SPIRE/J.Fritz, U.Gent/XMM-Newton/EPIC/W. Pietsch, MPE

Dale H. from the United States writes:

In an online discussion, I’ve found myself debating the use of ASC with regard to the Bible. It nearly always ends up arguing about if the one way speed of light has been measured, then I get bombarded by dozens of so called experiments that supposedly have proven it, but i then point out all of these experiments have been conducted within the same reference frame as Earth, I won’t list the list I was given. When you apply ISC toward frames with different velocities, paradoxes like Relativity of Simultaneity occur, right? So to blanket the entire universe with one synchrony convention, for all velocities, and all locations, is not possible is it? To argue that ISC is better than ASC, is like arguing the metric system against the English system, they aren’t competing models per se. It’s also begging the question, since they are assuming ISC is correct to argue against ASC, when that may not be the case, it also denies the Simultaneity Thesis, which they continue to ignore. I pointed this out, and this was the response I got. This is a physicist quoting another person in the discussion that responded to me directly.

“Hmm—I think you may be right! I will have to ask if there are any physicists lurking here that can give a definitive answer.
But, if light speed is very high only towards the earth, how is it we observe a younger universe the farther away we look? The farthest galaxies should look the same in age as the nearest … and they don’t.”


“Exactly. The universe looks ‘younger’ the farther out we look. The galaxies are smaller, younger (in terms of star metallicity), there are more collisions per unit area and so forth.”

Another aspect/observation (though I don’t know how this would necessarily work out in an anisotropic scenario), we can see light propagating across the interstellar medium, and in all cases light (or the timing of light reflections anyway) behaves as though light propagates at essentially uniform speed in all directions.


I wonder how one could resolve Monoceros 828, or even the reflections of SN 1987a in an anisotropic SOL scenario. Knowing that all points distant from the SN should ‘see’ the supernova at the same time, meaning that the reflected light from each point in the nebula should begin its journey to Earth at the same time. Further, for us to see those reflections in a timely fashion relative to the SN event itself, they must travel at essentially the same speed to us as the original light of the SN.”

Now … I’m no physicist, just using what I’ve picked up by reading, so I’m not the best person to be arguing at all with a physicist. But i do feel i can distinguish between real observable facts, and assumptions based on uniformitarianism. But am I correct to say that the light of 1987 supernova using ASC, would essentially reach earth near instantaneously, but the reflection of its shockwave within its own nebula may be slower (slower toward earth) because it’s no longer a one way line of sight, if its reflected its bouncing off gases or whatever, then heading toward earth …

I also cannot convince these guys that age is not observable, that a truck load of assumptions must first be used to reach an age of a thing. I gave the “candle in a room” analogy, but then they insist that the analogy is more accurate if you view the room next to another room full of identical type candles, all of different lengths … I contend that this is the same dilemma, that you don’t know the starting points, the rate of burn, along with more assumptions, etc. … before you can assign an age to the single candle. But they do not for one moment see that what they are assuming about the room full of candles, is being transferred to the single candle in question … so we have to see saw back and forth about “age” of stars, galaxies, etc. … what they call a “young universe” the further out we look, fits their ISC because they think the light has taken longer to reach earth …

What is the underlying assumption is this sort of argument that cuts to the real issue at hand? Would it be our starting points? Although I’ve already pointed this out to them, they still insist that age of stars, the one way speed of light, etc., are all observable aspects of nature.


CMI’s Dr Jonathan Sarfati replies:

We have known about Dr Lisle’s Anisotropic Synchrony Convention (ASC) idea for some time now. In fact, we published his initial paper in what is now our Journal of Creation in 2001, when he was writing under a pseudonym while completing his doctorate. See Distant starlight and Genesis: conventions of time measurement.

Our journal is partly a forum for discussion of new creationist ideas. But CMI tends not to agree with Dr Lisle’s ASC idea (although we do like his tu quoque counter Light-travel time: a problem for the big bang, which shows that this is not an anti-Lisle or anti-AiG [or anti-ICR for that matter] thing), regarding it as somewhat ad hoc. Not that multiple models are a bad thing by any means.

In particular, James Clerk Maxwell predicted electromagnetic radiation on theoretical grounds. He argued that an oscillating electrical field would generate an oscillating magnetic field, which in turn would generate an oscillating electrical field, and so on. Thus it would be related to the core electromagnetic constants: the permittivity (ε0) and permeability (µ0) of free space, which relate the strengths of electric and magnetic attractions. E.g. Coulomb’s Law is F = –q1q2 / 4πε0r2. Maxwell showed that this radiation would propagate at a speed c2 = 1 / ε0µ0. When the speed of light was found to match this, Maxwell deduced that light must be an electromagnetic wave. Einstein said that Maxwell’s equations were foundational for his theory of relativity: he reasoned that since they are constant for every observer, the speed of light must also be invariant, and instead time and length vary.

The symmetrical propagation of light makes good sense of the physics, and enabled the development of relativity. The two constants are scalars, at least in a vacuum, thus independent of direction.

In my own specialist field of spectroscopy, I certainly performed experiments as if c was symmetrical. That is, I used a diffraction grating that separates different wavelengths of light, and the relationship between separation and wavelength λ is well attested physics. From this, I measured absorption at different wavelengths. But here the key is the photon energy, which Einstein discovered is proportional to frequency ν, i.e. E = hν. The product of frequency and wavelength is c, i.e. c = λν. In one step, E = hc / λ. For this analysis, it worked to assume that c was invariant in all directions.

Now this doesn’t disprove Dr Lisle’s claim—attempts to do so have failed—but makes it superfluous at least in this case. Dr Lisle’s solution lacks any physical foundation for a speed of infinity towards the observer and c/2 away from him. Thus it is not a dynamical model (invoking causes of the motion), and seems as ad hoc as theories like cosmic inflation that Dr Lisle rightly decries in the other paper.

ASC is really a kinematic model (considering only motion without discussing causes), rather akin to Ptolemy’s epicycles in a geocentric cosmology. By contrast, a symmetric model is analogous to Kepler’s model of elliptical planetary orbits in an approximately heliocentric solar system, which enabled Newton to construct a dynamic model with his laws of motion and gravity. All the same, neither epicycles nor ASC can be disproved by any experiment.

Dr Lisle is right that it’s impossible to measure the one-way trip of light, as you note in your first paragraph. Even the pro-evolution Wikipedia notes in its one-way speed of light article (as of the date of publishing), “The ‘one-way’ speed of light from a source to a detector cannot be measured independently of a convention as to how to synchronize the clocks at the source and the detector.” [See also Update, below.]

Claiming that his idea is taught in the Bible reminds me of the church in Galileo’s time declaring that the Ptolemaic system was the absolute biblical reference frame (see also Galileo Quadricentennial: Myth vs fact).

We prefer the time dilation explanations by physicists Dr Russell Humphreys and formerly held by Dr John Hartnett (see their instructive forum Distant Starlight—A Forum DVD).

Update: In 2020, the science communicator Dr Derek Alexander Muller, not a creationist as far as we know, produced a lucid video on his YouTube channel Veritasium explaining the impossibility of measuring one-way speed of light.1 There have been a number of vain attempts. The Veritasium video even explicitly says that Dr Lisle’s idea of c/2 away from an observer and infinite speed towards him is a possible assumption that could not be disproved by any experiment, albeit without mentioning Dr Lisle.

Two cosmogonists in Australia, Dr Geraint Lewis and Dr Luke Barnes, also wrote a paper The One-Way Speed of Light and the Milne Universe, arxiv.org/abs/2012.12037. CMI friend Dave Coppedge explains the issues lucidly.2 Lewis and Barnes are also the co-authors of The Fortunate Universe (2016), which we reviewed in 2018. This shows that Dr Lisle was not making things up, but knows what he’s talking about, and what other experts in relativity are very familiar with.3

Dr Jonathan Sarfati

First published: 12 May 2012
Re-featured on homepage: 2 March 2024


  1. Muller, D.A. (Veritasium), Why the speed of light can’t be measured, youtube.com, 31 Oct 2020. Return to text.
  2. Coppedge, D., Nobody Can Measure the Age of the Universe, crev.info, 11 Jan 2021. Return to text
  3. Dr Lisle explains relativity and ASC in his book The Physics of Einstein: Black holes, time travel, distant starlight, E=mc², Biblical Science Institute, 18 Jan 2018. Return to text