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Does The Speed of Light Disprove The God of Scripture?

Summary: Experiment and observation has seemed to demonstrate that the God of scripture does not exist. Numerous problems, such as the constant speed of light, seem to show that the universe must be much older than scripture predicts. But are such arguments valid? In this article, apologist, Ben Fischer, shows that the one-way speed of light is not ultimately a science question, and that therefore, the argument cannot be reasonably foisted against the scriptures. To sign up for future emails, click here.


The Decaying Speed of Light?

On April the 4th of 1931, the prestigious journal, Nature, cited the following question: “If the velocity of light is constant, how is it that invariably, new determinations give values which are lower than the last one obtained?” (Nature, 522, 1931)

The somewhat troubling statement was drawn from the work of noted French astronomer, M. E. J. Gheury de Bray. He was said to have based his conclusions on nearly 75 years of observational research into the speed of light. (cf. Science, Vol 66, 1927) Several years after de Bray published his results, astronomer, Frank Edmunson, of the University of Indiana, suggested that de Bray’s observations could perhaps be best explained by adopting certain assumptions regarding the expansion of our universe.

“M. E. J. Gheury de Bray has directed attention to an apparent decrease in the velocity of light,” he wrote. “I have recently tried to explain this on the basis of the theory of the expanding universe.” Edmunson then went on to comment on de Bary’s work, admitting to the startling clarity of his research, conceding, “I determined … de Bray's data … represented the observations in a satisfactory manner.” (Nature, 759, 1934)

De Bray’s work was initially professionally tolerated. The idea that the speed of light was gradually slowing was “big news.” He therefore published his findings for a total of three times, with two of his reports featured in the most respected journal of his day. Later reviews of his work gradually changed as the astrophysical community came to repudiate the concept. At present, no discussion is being entertained on the subject of the gradual slowing of light’s speed.

The topic of light’s speed is, of course, important for many Christians. Some have considered it as an obstacle to faith. Through examining the book of Genesis, these believers have insisted that the current rates threaten the Bible’s "recent-universe claims." Others have concluded that such concerns are unfounded, since Genesis may be reread to accommodate for a greater age—a solution many skeptics have treated with contempt as a shameful ploy to rescue the Bible’s case.

The question is: Do the current measures threaten the scriptures? Must Christians resort to rehashing de Bray’s claims? Or, should believers rather search the book of Genesis in order to harmonize the speed of light with faith? Some gospel defenders, such as Barry Setterfield, have contended that de Bray’s work is the key to settling the case. (Setterfield, 1987) But need we suppose that current speed of light theory has anything to say about matters of science and faith?

The Bible's Alleged Science Problem

Recently, I confronted this question while delivering a lecture. I was speaking on the subject of our current theories of cosmic beginnings. Our class had been discussing numerous proofs for God’s existence and had now begun to explore the most common scientific counter-claims. Among the various options, we had examined the belief that the Big Bang has somehow replaced the God of faith. (See lecture) It was then that a student responded with a vitally important question which challenged the deeper purpose behind our broader gospel-case.

“The problem you have presented appears daunting,” he admitted. “A supernatural cosmic origin must replace the Big Bang. But how does this prove the God of the Bible?” he continued. “Perhaps the God of creation is more generic than you have presented. In that case,” he queried, “why continue pressing the issue? Why bother insisting that the Big Bang never happened? Doesn’t science, for other reasons, still disprove the God of scripture? Maybe we ought therefore to abandon these sorts of discussions.”

There was no denying the point: The objection was compelling. The Big Bang argument only poses a limited threat. Conversely, the causes for denying scripture are reportedly legion. Science offers us seemingly endless reasons for rejecting the Christian faith. Evidences from the field of astrophysics, for example, have convinced numerous Christians that old assumptions must now be replaced. All of this has increasingly persuaded modern believers that there is simply no longer any reason for science and faith debate.

As I paused to consider the proposition, the facts were hard to resist: Science indeed seems to challenge a number of scripture’s claims. The book of Genesis, for instance, has been the cause of much discussion, with the time-scale of creation forming the heart of the debate. Yet in the months prior to my current presentation, I had slowly begun to wonder why these issues continue to rage. In fact, given my recent reading, it appeared that modern science lacked an objective grounding for establishing its critical case.

I therefore began to recount my latest research—namely; my study into the rapid speed of light. Here, modern science has long contended that light years are shorter than the scriptures would have us predict. Thus even the smallest distances are simply too vast for the speed of light to somehow travel or shortly traverse. Accordingly, modern skeptics argue that Moses was mistaken about the timing of creation as well as the God he claimed existed.

The speed of light certainly evokes perplexing questions. Christians often view it as one of the most difficult doubts to resist. But the challenge of distant-starlight surprisingly arouses more questions about the limits of science than about the God of holy scripture. Fundamental problems about the speed of light in fact continue to energize science circles today. Remarkably, none of the most puzzling questions have anything to do with de Bray’s radical claims.

The One-Way Transit Problem

I therefore sought to discuss the biggest problem: The age-old challenge of measuring the one-way speed of light. Essentially, the issue stretches back to the days of Aristotle who attempted to settle the question through crude lamp and shutter experiments. Later investigation revived in the nineteenth century, just a few scant years prior to Einstein’s seminal work. The world of modern physics has ever since remained gridlocked on the question of how to measure the speed of light in one-way transit.

Unfortunately, typical laymen often seem to miss the point here. Many fail to see that this is different from what de Bray was claiming. In fact, conflicting opinions about the one-way speed of light have nothing to do with the idea that the speed of light is therefore changing. The situation is rather that the entire phenomenon lies beyond the purview of science, with no hope of remediation. In simple terms, the one-way speed of light cannot be observed. This leaves us with no ability to test the matter in question.

To illustrate the problem, just consider the following example. (Many of my students seem to appreciate this experiment.) Imagine that you are standing on a basketball court located somewhere in lower east Manhattan. As you busily dribble, your mind is aware of the length of time it takes for the ball to hit the pavement. Using both your senses of sight and sound, you clock your dribble internally creating an ease of play and motion.

Now imagine that your powers of seeing and hearing are suddenly removed. How in such a case, could you measure the ball’s motion? With no ability to properly use your senses, you would quickly become unable to track the ball’s rebounding movements. This would make it impossible to measure the time it takes for the ball to leave your hand and hit the floor beneath you. In fact, the only way to know the ball has hit the pavement is if it returned to the hand you used to set it in motion.

Now this is precisely the problem with measuring one-way light. Human beings can only see light in two-way transit. Hence we only know a beam of light has hit a reflective object if the light has returned to the observer using the lamp that sourced its motion. Astrophysicists therefore cannot measure one-way light speed any more than Helen Keller could play defense for the New York Knicks. The question simply lies beyond our empirical borders. In other words, properly speaking—this is not a science question.

For this reason, I began to challenge my students accordingly. I spoke to them of the problem so often found in these sorts of protestings. For skeptics who claim that science disproves the God of scripture often don’t pause to examine the basis for their own objections. Speed of light theory in fact has proven fairly convincingly that light in one-way motion may be clocked to suite our preferences! The point is, astrophysics will never settle this question. The speed of light cannot therefore be used against the scriptures.

Examining my students faces, however, I could see that some they weren’t convinced. A few seemed to be fooled by their own counter-intuitions. For if we know the two-way speed of light, then what is to prevent us from taking our measured values and simply dividing the speed in half? But such solutions are frankly viewed by modern scientists as ignorant of the challenges which the problem here presents. In fact, this sort of answer has failed to sway the current guild of scientists that the issue has now been finally settled.

About this, Albert Einstein conceded defeat. Following his years of study, he eventually capitulated to the point completely. Through pondering the implications of his ground-breaking research, he admitted that one-way light speed is not subject to human observation. “[The amount of time] light requires … to travel from A [to] [B] … is in reality [not] … a hypothesis about the physical nature of light, but a stipulation which I … make of my own free will in order to arrive at a definition of simultaneity.” (Einstein, 1954, 23)

Albert Einstein’s words deliver a powerful point: There is no physical consequence to adjusting light in one-way transit. So long as the speed of the two-way trip remains essentially unaffected, the observer may choose from an infinite number of conventional speeds and measurements. Thus the speed of the basketball’s vertical drop is entirely irrelevant if the pitch and bound of the ball remains consistent to the player. There is therefore no physical basis for saying that light takes all of billions of years to reach our planet’s surface.

Of course, this is not to say that Einstein’s work is fully accepted. At times, scientists will claim to have cracked the hundred-year mystery. Thus Alan Janis comments: “[E]ditors of respected journals continue to accept, from time to time, papers purporting to measure one-way light speeds.” He then went on to dryly state: “[An] [a]pplication of the procedure [I] described shows where their errors lie.” (Janis, 2018) Incidentally, the examples featured in this article are wholly parallel to Alan Janis’s basic contentions.


I therefore closed my argument by summarizing the point: Changing one-way light speeds yields no physical consequences. But this also means that evenly dividing the two-way trip ultimately produces no physical consequences either. Skeptics therefore cannot use two-way light speeds to demonstrate that Genesis was wrong or that the God of scripture does not exist. In fact, this claim is a profound abuse of science on a subject where, properly speaking, human imaginations should refrain from interfering.

May you therefore by blessed as you contemplate deeply the faith that you have come to joyfully profess. And may you be inspired to gaze in awe and wonder at the infinite wisdom of our Creator God who is forever blessed. Amen.

Postscript: The above article only deals with one argument from astrophysics against scriptural inspiration. To see positive evidence for the existence of God, please visit us online at


  • M. E. J. Gheury de Bray, “The Velocity of Light,” Science, Vol. 66, 30 September 1927, Supplement, p. x.

  • M. E. J. Gheury de Bray, “The Velocity of Light,” Nature, 24 March 1934.

  • M. E. J. Gheury de Bray, “The Velocity of Light,” Nature, 4 April 1931.

  • Frank K. Edmunson, Velocity of Light, Nature 133, 19 May 1934.

  • Barry Setterfied and Trevor Norman, “The Atomic Constants, Light and Time” Stanford Research Institute International, Technical Report (August 1987) Posted online ( without SRI International’s permission.

  • A. Einstein, Relativity, The Special and General Theory, translated by R. W. Lawson 15th ed., enlarged (London: Methuen, 1954).

  • Alan Janis, Conventionality of Simultaneity, Stanford Encyclopedia of Philosophy. Last viewed July 1st, 2019:

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