The question, “WHAT LIMITS LIGHT SPEED TO 300,000,000 m/s — NOT MORE OR LESS?“, posted on an internet discussion site, has led to, at last count, over 400 comments from a wide variety of responders. Many of these claim Ph.D degrees in modern physics. Most are apparently knowledgeable in the sometimes clear, sometimes very confusing, and sometimes downright incomprehensible accumulation of formulae, acronyms and references of relativity and quantum theory. No simple answer has arisen. No clear answer has been posted. This is too bad, because the question gets to the very foundation of modern physics.
It is a good question for the reason that, as modern physics sees it, the velocity of light, c (and all other forms of electromagnetic radiation) is one of the most tested, most measured, confirmed, and relied upon constants in nature . It is not only generally agreed upon and accepted, it has become the basis for other constants and standards, such as the definition of the meter (the distance light travels in 1/299,792,458 of a second); Planck’s Constant h (6.626068 × 10-34 m2 kg /s); and astronomical distances (light-years), for example. The velocity of light, then is not a hypothetical number, not like Einstein’s cosmological constant, which was a “take it or leave it number” depending on whether you thought the universe was expanding or not. “c” is an empirically derived and confirmed constant.
So, the question is really asking “What is it in the nature or structure of the universe that establishes and maintains that invariant limit?” Contributors to the discussion have submitted everything from mathematically derived theories to some that seem more mystical than real. But to get at it within the realm of reality requires looking at it on the basis of what else we know and what we believe is real and true.
Over the last hundred years or so physicists, cosmologists, even philosophers have identified many facts about the nature of the universe and the workings of its many parts. Light has been intensively studied for over 400 years, so it is one of the most known of the basic elements of that universe. Newton with his prisms was able to identify its constituents as many colors blending as a whole into the clear white element we perceive with our organs of sight. But Newton saw light as being divided into tiny particles, not as a continuous fluid-like element. Later, in the early 1800’s Thomas Young, after watching the behavior of water through and around barriers to its flow set up an experiment with light (Young’s Double-slit experiment) that appeared to prove that light must be made up of waves, since it appeared to behave just as water. This interpretation held until the early 1900’s when Einstein and others brought us back to a particle theory of light, that it was made up of tiny “quanta” of energy which came to be known as photons. Now, of course, photons are considered to have no mass, hence no energy, in accordance with another of Einstein’s laws. But light still behaved as it did in Young’s experiment, and this quandary contributed to one of the major paradoxes and elements of true belief and argument of modern physics, which has come to be known as “wave-particle duality.”
The main thing that modern physicists do agree on, however, since long before our time, is that all of the universe we see, feel, touch, taste and smell, and even those things that we perceive only with sense-enhancing or prosthetic devices like telescopes, particle detectors and the like, is made up of tiny, microscopic, even sub-microscopic elements that have been known as “atoms” since the early Greeks, as “first-beginnings” by writers like Lucretius in the first century BC, to electrons, protons, neutrons, hadrons, bosons quarks (of multiple varieties), most of which we know only by our perceptions of their effects and some only by predictions that they must exist. And in the latest models, from the 1920’s to the present day, these elementals are assumed to share the same characteristic, that they sometimes behave as particles, that is, as tiny impenetrable singularities that carry electrical charges and other qualities denoted as spins, polarities, and behaviors with names such as entanglement (the ability to control other, similar elements at a distance), superposition (two or more occupying the same space at the same time), and the like. And most of these new elements that make up our universe seem to share this same characteristic, of behaving sometimes as waves and sometimes as particles.
While to the ordinary reader, some of these ideas may seem paradoxical, even contradictory to ordinary experience here in the macroscopic world, most have become totally acceptable beliefs, particularly among the those engaged in the large field of quantum physics. And, to be fair, the mathematics and other principles of this discipline have proven remarkably successful predictors in modern technology, particularly in computer science, electronics, and communication; and this success has led to the belief that this model must be the true. “If the math works, the theory must be correct” in spite of the as yet uncorrected and unexplained paradoxes and contradictions.
In this light, we should also remember how much of the success and progress of the industrial revolution was the result of earlier scientific developments such as those of Newton, based on theories we now know were incomplete and in some cases inaccurate, particularly when applied to studies beyond the familiar scale of ordinary objects. )I have called this place where Newton’s laws are still applicable the “zone of middle dimensions” after a note by Elizabeth Rosner, author of “The Speed of Light,” a novel.)
So, in light of the question posed at the beginning of this discussion, let’s look at some slightly different ways in which one might look at this as yet unexplained concept we mentioned earlier, that of “wave-particle duality.” It seems that there may be three ways to consider the observations we have made as to the nature of the tiniest elements we see as making up the contents of our universe.
One, that the universe is made up of “things”, for want of a better word, that sometimes appear to us and behave as if they are particles, and sometimes as if they are waves; and that because of a law we have come to know as Heisenberg’s Uncertainty Principle, we cannot generally predict how and where they will appear in one form or the other. As we have seen, this is the currently accepted concept with all of its apparent paradoxes and contradictions but accepted as truth because the whole system seems to work.
Two, the entire universe is made up of “particles” but for some as yet unexplained reason, they sometimes behave as if they are waves. This idea goes back many centuries because our everyday experience shows us small elements making up larger ones (our everyday world model is “matter-centric,” and “particles” fit that model). And, except for a few things in our experience like electricity and magnetism for which there are a whole other set of laws and rules, this seems to work.
Three, The entire universe is made up of waves, but these can sometimes appear to us as if they are particles. At first glance this may seem counterintuitive, but a serious case can be made for it and the mechanisms by which it can occur can be demonstrated without invoking any contradictory or paradoxical elements. And at the scale we are talking about, mass, a distinguishing characteristic of “particles”, is already shown in electromagnetic values, in electron volts.
Of these three alternative views of the submicroscopic world, only the third alternative model, that of a universe made up entirely of waves, can be shown to be consistent from the smallest scale of existence on up through the largest, cosmological scale of the universe and beyond. To accomplish this feat, one must simply assume, first, the existence of a medium, once called the ether, in this case an electromagnetic ether, filling all of the conceivable bounds of what we call space.
Where did this electromagnetic ether come from? How can we assume such a thing exists? Well, consider the alternative models that have been put forth. Most cosmologists and most astronomical physicists believe that it all began with a big bang somewhere in what some call the void and some call the vacuum. When you ask how, the answer seems to be that the void or vacuum is not really an empty place as one might assume, but is filled with what are called by some as quantum probabilities, or singularities from which it all sprung. And when you press them, the most common answer today is, “Well, of course, it started from nothing.” If you believe in any concept of reality (and quantum physics today is not the place to easily find that belief) and its corollary, that something cannot come from nothing, then one must assume that something fills that void. Based on all we know about what we call matter and energy and their interchangeability, via the relationship postulated in Einstein’s equation, E = mc2, a reasonable choice is that what fills the void is an electromagnetic field, what we’ve been calling the ether. The possibility of its existence can be derived directly from a set of historically proven laws, Maxwell’s Equations, particularly the third and fourth of these tried and true, universally accepted principles. These equations state, in english translation from the math, that, “3. An electric field is created by a changing magnetic field, and, “4. A magnetic field is created by a changing electric field.” The key concept here is that “a changing electric field produces a changing magnetic field even when no charges are present and no physical current flows. Through this mechanism electromagnetic waves may propagate through even a perfect vacuum, as changing magnetic fields produce electric fields and changing electric fields induce magnetic fields.”(1) One could almost say that if these laws are true, that the existence of such an ether is highly probable.
Now, if we accept the truth of premise 3, above, “The entire universe is made up of waves, but these can sometimes appear to us as if they are particles.” Then light, too, is a wave-like electromagnetic phenomenon, not particulate, and that the medium on which it is carried is an electromagnetic field, then its velocity must, of necessity, be determined by the underlying structure of that medium . Note, that I did not say “—through which it passes.” Hence there is no resistive medium through which it must force its way, which “massless” photons might find impossible. What we call “light” is an electromagnetic wave phenomenon of a particular range of frequencies, visible to our sense organs and their prosthetic enhancers, which is carried on an underlying wave structure just as our wireless telephone signals and data, our radio communications and the like are carried, at a constant, invariant velocity, unimpeded by molecules of the atmosphere and most other supposedly resistive elements.
What, then, is then, is the likely nature of this medium, and how does it connect to the constant value of the speed of light? The answer seems to lie in that other constant we mentioned earlier, the one called called Planck’s Constant. It is, in fact, a precise number, 6.626068 × 10-34 m2 kg /s. It ties c, the velocity of light, to the total energy of an event or entity. From this relationship Planck developed a set of “Planck values” the most significant of which for us in this discussion is the Planck length, l, a unit of length equal to 1.616199(97)×10−35 meters, which, in most circles of modern physics, considered to be the shortest measurable length. Originally derived from the relationship between Planck’s Constant, the velocity of light, c, and the gravitational constant, G, this value turns out to be remarkably close to the value of 1/h, the reciprocal of Planck’s Constant itself. The formula which ties observed values to the underlying structure of the universe is E = hv. In the minimal case the E involved is meant to be the energy of a photon, v the frequency, and h, the constant derived from observation. This implies that a photon is a quantum, but the mathematics serves the same purpose if E refers to simply a unit of energy carried by a unit value of a wave.
Planck intuited that physical action could not take on any indiscriminate value. Instead, the action must be some multiple of a very small quantity (later to be named the “quantum of action” and now called Planck’s constant). What this tells us is not that everything must be organized as individual “quanta” of energy, but that the underlying structure of the electromagnetic field may be continuous and smooth, but has a lowest limit of measurement, that is, the smallest unit of measure available to us equal to 1 Planck Length.
Trying to measure anything using a smaller scale than this would then be impossible. For example, if one draws a line on a sheet of paper and places on the line tick marks one “Planck length” apart, each segment of the line does not become automatically independent of each of the other units on the line but remains part of its continuous structure, just as a frequency value is not a separate unit of a wave but only a unit of measurement. Taken to the next step, this relation suggests a value for the frequency of vibration of the underlying electromagnetic ether is likely to be 1/h. That frequency would then have a value of about 1.612 × 1035 Hz. The invariant velocity of light that we have observed and measured is a direct clue to this conclusion.
There is a famous comment by the best known proponent of fractal geometry, Benoit Mandelbrot, in his paper “How long is the coast of Britain?”. The response to the question is “how short is your ruler?” The smaller the ruler, the more detailed and the longer, the measure will be. What Planck’s Constant gives us is the length of the shortest unit of measure we can use to measure the size of the universe.
So, the answer to the question “What limits light speed to 300,000,000 m/s, not more nor less?” is simply that its velocity is inextricably tied to the frequency of the finest level of the “fabric of the cosmos” as some have called it, on which light is carried. and which permeates all of the real fields and objects, those visible and otherwise detectable, coherent, stable distortions of the electromagnetic field that make up the elements of our universe, perceivable to human senses or not, in its vast but definable bounds.
How fortunate we are to have been able to piece out the workings of this mechanism on which so much of our modern world depends. In other places and other writings, I have attempted to show how this premise, which does away with “wave-particle duality” and most of the other paradoxes of relativity and quantum theory can be shown to apply at cosmological scales as well as at those of the tiniest elements of our universe and beyond. Some of these can be found on my site at enquiriesnw.com and in my book “the picnic at the edge of the universe”, which is only a draft, a preliminary sketch of a more complete model. It is my intent to continue these efforts to build a comprehensive, consistent model, one more firmly based in reality and less dependent on only mathematics. We should always be cognizant that mathematics is a language, albeit a beautiful and useful one, for the purpose of describing and communicating concepts difficult and sometimes impossible to make clear in words and sentences. But, like our other languages, English, French, Farsi, even Latin and Sanskrit, it can be used to write documentary narratives, nonfiction, scientific papers, but also myths and fictions, even poetry on occasion. Much of modern physics is based purely on mathematics with the result that we are asked to believe that, for example, “reality exists only when we observe it” and “observing a phenomenon automatically changes its characteristics and nature,” assertions that challenge thousands of years of science and philosophy. Einstein, a fierce believer in reality (except, perhaps in his own equations about relativity), challenged the correctness and completeness of quantum theory for the last thirty years of his life on just this principle. If we are careless about the distinction between reality and its opposites, we can sometimes base conclusions about reality on fantasy. We must be constantly on the alert that we do not mistake one for another.