The History of Light Speed Research
The minimum value of the speed of light
Why is c not measured as changing now? addition September 5, 2003
On the Measurement of Time, and the Velocity of Light
Responses to critical webpages
Supportive and Explanatory Essays by others
Lambert Dolphin's page of collected relevant links and abstracts
For a basic history of the light speed work and measurements through time, first please read A Brief History of c (Barry Setterfield, 1987) and Helen Setterfield’s article as originally published in Chuck Missler's "Update".The work with the data was originally published by Trevor Norman and Barry Setterfield in their 1987 Report, "Atomic Constants, Light and Time," requested by Lambert Dolphin, a senior physicist at Stanford Research Institute International, as an internal document, or white paper, for their discussion. The paper was reviewed by professors in related fields at Flinders University in South Australia, where the two men were working, and Flinders itself published the paper in 1987.
Question: Was this material about the speed of light changing talked about before?
Setterfield: Between 1880 and 1941 there were over 50 articles in the journal Nature alone addressing the topic of the decline in the actual measured values of lightspeed ( c). For example in 1931, after listing the four most recent determinations of c, De Bray commented in Nature "If the velocity of light is constant, how is it that, invariably, new determinations give values which are lower than the last one obtained ...? There are twenty-two coincidences in favour of a decrease of the velocity of light, while there is not a single one against it" (his emphasis). The interest was world-wide, and included the French, English, American, German and Russians. In addition, these discussions included some consideration of the fate of the newly developing concept of relativity if c were not a constant.
The whole discussion was brought to a close in August of 1941 by Professor R. T. Birge in an article dealing with the changing values of the atomic constants "With special reference to the speed of light" as the title stated. Birge's first paragraph raised many questions. In part it read: "This article is being written upon request, and at this time upon request.... Any belief in a change in the physical constants of nature is contrary to the spirit of science" (his emphasis) [Reports on Progress in Physics (Vol. 8, pp.90-100, 1941)]. Although this article effectively closed the whole discussion, the data trend continued. This was documented in our 1987 Report.
Please see Table A in the 1987 Report. These statistics were illustrating the fact that, in a situation where c was measured as changing, it was nonetheless true that at a given date (1882), three different methods of measuring c obtained the same result to within 5 km/s. In other words, these methods were giving consistent results. This is an important point. It was picked up by Newcomb in 1886 when he stated in Nature that the results obtained around 1740 by the two methods employed then gave consistent results, but those results gave a value for c that was about 1% higher than in his own day. Later, in 1941, history repeated itself. In that year Birge commented on the results that were obtained in the mid-1800’s by the variety of methods employed then. He acknowledged that "these older results are entirely consistent among themselves, but their average is nearly 100 km/s greater than that given by the eight more recent results." What cannot be denied is that there was a systematic drop in the values of c obtained by all methods. Even Dorsey, who was totally opposed to any variation in c was forced to concede this point. He stated "As is well known to those acquainted with the several determinations of the velocity of light, the definitive values successively reported…have, in general, decreased monotonously from Cornu’s 300.4 megametres per second in 1874 to Anderson’s 299.776 in 1940…"
Comment: Perhaps he [Birge] had in mind the idea that c was varying, just by itself, without being given a dynamics from its own term in the physical action S. That idea would violate the time-translation invariance, and likely the space translation invariance also, of physical law. In addition to blaspheming the uniformity of natural (which could evoke the "contrary to the spirit of science" remark), it would destroy the conservation of energy and momentum. That is one reason why I so strongly urge that any such theory be presented formally as a relativistic classical field theory, in which Noether's theorem(s) ensure energy and momentum and angular momentum conservation.
Setterfield: First of all, you will note in the 1987 Report that there is a consistent trend in seven atomic quantities on the basis of conservation of energy, as shown in Table 24.
The issue of relativity is discussed in the report in the section entitled The Speed of Light and Relativity.
Here is the point. All methods of measuring c have given consistent results at any given time, but the values of c have dropped with time. This can be illustrated by the results from Pulkova Observatory alone where the value of c was obtained from the aberration method first used by Bradley. The Pulkova Observatory results were obtained using the same equipment on the same location by experienced observers over a long period of time. The observational errors remained unchanged, as did the inherent accuracy of the equipment. Nevertheless, from 1750 to 1935 the value of c obtained from this observatory dropped by more than 750 km/s. When all the results are in, each method individually revealed the drop in c, as did all methods lumped together. These results are backed up by changes in other atomic constants that are associated with c through the conservation of energy. One reviewer of the 1987 Report, who had a preference for the constancy of atomic quantities, noted that instrumental resolution "may in part explain the trend in the figures, but I admit that such an explanation does not appear to be quantitatively adequate." The Pulkova results prove that this is not the cause of the trend. Indeed, when the professor of statistics at Flinders University examined the data in the Report, he felt that a prima facie case existed for c decay and asked us to prepare a seminar for the Maths Department. In all the subsequent discussion and turmoil that the 1987 Report engendered, he stood by this assessment.
Question: How small are the differences in the speed of light that we are talking about, since instrumentation became accurate?
Setterfield: The differences in the speed of light that we are talking about since instrumentation became accurate (about 1700) is about 3000 + kilometers per second. That is, about 1% higher compared to today's value. Some comments from the journals may help here:
From 1882 to 1883, Professor Simon Newcomb measured the speed of light in a series of definitive experiments. At this same time Albert Michelson had independently performed a series of experiments to determine the speed of light as well. In that same year, Nyren had determined the speed of light by the aberration method. The value obtained by these three experiments was 299854 +/-5 kilometers per second. In other words, they were in agreement to within 5 km/s. In 1886, Professor Simon Newcomb admitted that the definitive values accepted in the early 1700's were 1% higher than in his own day. [Nature, 13 May, 1886, pp 29-32]
Interestingly, history repeated itself. In 1941, Professor R.T. Birge, in looking over the most recently obtained values for the speed of light, commented that the measured values of c from the 1880's "are entirely consistent among themselves, but their average is nearly 100 km/s greater than the eight most recent values." [Report on Progress in Physics, vol. 8. pp 90-101, 1941] So the difference was noticeable.
However, you raise the validity of the early measured values of lightspeed by Roemer and Bradley. Let us take Bradley's abberation measurements first. The same method using the same equipment was being employed at Pulkova observatory from about 1780 until about 1940. The data collected by this abberation method from Pulkova using the same equipment showed a consistent decline which amounted to 890 km/s over a period of 160 years. This is far larger than the error in measurement at Pulkova which averaged around 150 km/s. As far as Bradley's measurements themselves were concerned, I have listed the measurements he made on 24 stars over a period of 28 years, along with the reworkings of 5 different authorities. These are discussed in detail in the 1987 Report "The Atomic Constants, Light and Time" and the associated Tables 2 and 3. The result was 300,650 km/s, just 858 km/s above the present value. This final result omitted the re-workings of Busch which would have increased the mean value to 1632 km/s above the present value, but all that detail is documented in the Report. Before the critics say that the figures are hopelessly wrong, it is respectfully suggested that they check the original data for themselves and point out where the experts that re-worked the data have gone wrong.
As far as Roemer is concerned, some misleading statements by one recent authority have led to conflicting claims. Observations by Cassini gave the earth orbit radius delay for light travel as 7 minutes 5 seconds. Roemer gave it as 11 minutes from a selection of data. Halley noted that Roemer's figure for the delay was too large, while Cassini's was too small. Newton listed the delay as being between 7 and 8 minutes in 1704. Since then, observations using Roemer's method all gave results higher than today's value. Delambre, from 1000 observations around 1700 gave the delay as 493.2 seconds which gives a value of 303,320 km/s. Martin in 1759 gave the value as 493.0 seconds. Glasenapp in 1861 gave it as 498.57 seconds, Sampson in 1876.5 gave it as 498.64 seconds and Harvard gave it as 498.79 +/- 0.02 seconds which translates into 299,921 km/s +/- 13 km/s. Accordingly, while Roemer's exact value is debatable, the other documented values by this method all indicate that c was higher then. The details about all of this are available in the Report.
Setterfield was pressured into some early publication of some of his material in progress in the early 1980’s. Please disregard this material as everything there has been either finalized or updated in subsequent material. The first important paper was Atomic Constants, Light and Time, written in 1987 in response to a request from a senior physicist at Stanford Research Institute International.It was attacked on primarily statistical bases, and defended by Alan Montgomery, a professional statistician and Lambert Dolphin, the physicist who had originally requested the paper. A more complete and sophisticated analysis of the Setterfield work was done by Montgomery himself. Malcolm Bowden also took the time to deal with some of the challenges. Other challenges were responded to in published materials and private correspondence for five years following that work, at which time Setterfield resumed his research.
The 1990’s Tifft’s work on the redshift and the challenges and extra research concerning it were being debated. This material turned out to have strong implications for the Setterfield research. One of the results of putting all of this together was Atomic Quantum States, Light and the Redshift, a paper which was never published, but which is currently being divided into a series of other papers with fuller explanations. Two of them are Is the Universe Static or Expanding? And Exploring the Vacuum.
Gradually a model has been emerging from all of this: a model not expected, not originally looked for, and one that disagrees with both the evolutionary/long ages ideas and the standard creationist and young earth ideas. This model is roughly outlined in A Brief Earth History and A Brief Stellar History.
Upon request, two essays were also written to deal with the material in a general and basic way. The first was written by Barry with an anticipated audience of those having some small background in physics. It is The Vacuum, Lightspeed, and the Redshift. Then a second, much more basic paper aimed toward the general lay audience was written by Helen Fryman (Setterfield), entitled A Simplified Explanation of the Setterfield Hypothesis.
Currently, Setterfield is researching into a field which he has been repeatedly questioned about: mass. This has been a field of much speculation and study in physics especially recently in terms of what mass actually is. When one considers that Einstein’s famous equation, E = mc2, combines mass with energy and the speed of light, it is clear that there are properties of both mass and energy which must be both defined and understood in order to make sure this emerging model is cohesive.
Regarding a number of the papers listed above, many questions have come in through the years. Immediately following is discussion explicitly pertaining to the methodologies followed by Barry. Discussion and questions regarding the various areas of research will be on the associated pages and may be found by returning to the Discussion Index.
Other Physical Processes if the Velocity of Light is not Constant. (Barry Setterfield)
SEVEN RELEVANT BASIC FEATURES OF THE NEW THEORY:
1. Photon energies are proportional to [l / c2)].
2. Photon fluxes from emitters are directly proportional to c.
3. Photons travel at the speed of c.
4. From 1 to 3 this means that the total energy flux from any emitter is invariant with decreasing c, that is, [ 1 / c2 x c x c ]. This includes stars and the radioactive decay of elements etc.
5. Atomic particles will travel at a rate proportional to c.
6. There is an additional quantisation of atomic phenomena brought about by a full quantum ± of energy available to the atom. This occurs every time there is a change in light-speed by ± 60 times its present value.
7. A harmonisation of the situation with regards to both atomic and macroscopic masses results from the new theory, and a quantisation factor is involved.
RESULTS FROM THOSE SEVEN FEATURES:
A). From 2, as photosynthesis depends upon the number of photons received, it inevitably means that photosynthetic processes were more efficient with higher c values. This leads to the conclusions stated originally.
B). As radiation rates are proportional to c from 2, it inevitably follows that magma pools, e.g., on the moon, will cool more quickly. Note that A and B are built-in features of the theory that need no other maths or physics.
C). From 6 and 7, the coefficient of diffusion will vary up to 60 times its current value within a full quantum interval. In other words there is an upper maximum to diffusion efficiencies. Otherwise the original conclusions still stand.
D). In a similar way to C, and following on from 6 and 7, the coefficient of viscosity will vary down to 1/60 times it current value within the full quantum interval. This implies a lower minimum value for viscosities. Within that constraint, the original conclusions hold.
E). In a way similar to C and D, and again resulting from 6 and 7, critical velocities for laminar flow will vary up to 60 times that pertaining now, within the full quantum interval. The original conclusions then hold within that constraint.
F). As the cyclic time for each quantum interval was extremely short initially, it follows that it is appropriate to use an average value in C, D, and E, instead of the maximum: that is, about 30. As c tapered down to its present value, a long time has been spent on the lower portion of a quantum change with near-minimum values for C, and E, and near maximum values for D. These facts result in the effects originally elucidated.
Dear Mr. Setterfield,
Today I came across the variable speed of light on the internet. I decided to investigate it. In that investigation I found your original paper on the variable speed of light and read it. I realized from the assumptions that the paper was flawed so I am motivated to point out that mistake in the paper with this email.
In the assumptions you state that all methodologies of measurement were lumped together. This is a mistake to lump methodologies and the conclusions are to be discounted because of this mistake. I'll explain.
Measurement is fickle. No two methodologies can be averaged for a conclusion, methodologies can be compared for usefulness, but not lumped together. I developed aerospace materials for 18 years and learned this lesson the hard way. NASA uses the ASTM methodologies, rigorously defined for reproducibility anywhere. Different methods were not accepted, only the method NASA concluded would produce good enough results to get the job done so the spacecraft would behave as predicted. The reason for this heavy-handedness by NASA is that in general, once a spacecraft goes up, no one can repair it, and the spacecraft must be engineered to work right the first time, so measurement must be defined, reproduceable, and standardized in the ASTM when appropriate to the customer specifications and then entered into the contract as quality control methodologies. Indeed, contracts with NASA are a lot of paperwork.
Because all data was lumped together, the next step was to subject the data to a curve fit. After that step, you are indeed destined to be drawn to your paper's conclusions. The assumption to lump the data is a mistake, the next two steps, curve fitting and drawing conclusions, do not hold, but they do logically follow. Many people will accept the logic and thus accept the conclusion. In my experience, few people examine assumptions. Many papers which use data can be analized in this way and found to fall down. The subject is not wrong, the methodology is not wrong, only the assumptions, and when the assumptions are wrong, the methodology cannot justify the conclusion, so the conclusion is wrong. This is a brutal truth, but I can explain more.
If you examine each methodology by itself, for instance, the laser, you will see a sociological effect, the improvement of the methodology and the technology over time, reflected in the data. The data reported in your paper for the methodology of laser demonstrates that the methodology has settled down into reproducibility and is producing a constant value for 'c'. Several other methods show the measurement result 'settling down' as the method 'improves' over years or decades. Because of this settling effect the earlier data is discounted and the moste recent reproducable results are trusted. We used this technique to make aerospace materials and it works. What matters in engineering is not conclusions but only if you do what works. So, good engineers who understand measurement are then allowed to engineer again. The bad engineers look for another job to engineer again.
Measurement is a very subtile and difficult part of scientific thinking. Indeed the data demontrates to me in an intuitive fashion the socialogical effect of history upon the resulting measurement. Scientific thinking is difficult, it is based upon assumptions, conventions, and agreement. It is never right, it only approximates. It is in constant upheaval. Science will never know the truth, it will only know what works in the world today. There is nothing wrong with science, its paradox is that it is not absolute yet it provides the base of knowledge for the engineers of technology to create the machines we employ today, such as the internet and this email. When science is political, such as the current philosophical conflict between science and creationists, well, it is only politics. The email still goes through because of the engineers. All that matters is what works, good science works, bad science does not work.
Science is not theology and cannot be such. Science will never tread the path of theology. I discounted the theological conclusions on creationist web sites once I saw the assumption in the paper of lumping the data together. That paper was flawed, as my experience in making spacecraft parts has demonstrated.
Assumptions are fundamental to success. If you want VSL badly enough you will change your assumptions. I assume the intent of the paper was honest, but methodology was flawed. If the intent of the paper was to push a theological agenda then the paper would be dishonest and you would have to face God about that at some point. I do not know your motivation.
It does not matter if the speed of light is variable or not. I am not against VSL therory, I am against poor methodologies. Indeed, Magueijo is attempting to exploit VSL, http://theory.ic.ac.uk/~magueijo/. Perhaps VSL will be proven, much the same way that Einstein upset the world with the notion of variable time and how it eventually was proven. My 'scientific' guess from the data you presented is that if variability exists, the actual variability would be a very very small number. VSL would then be true, but, an unusable concept to the creationist web sites which exploit it to prove the date of creation at about 10,000 years ago. The whole notion of proving this date seems to me no different than counting the angels on the head of a pin, more politics than truth searching.
Good science is like good theology, it is what lasts over time, it is what people find usable, it is what gets written into history. Indeed, we no longer hold all of the ancient beliefs, times change, some beliefs change, and indeed, our beliefs of today will not all be present in the future, only those beliefs which are usable will endure in those of the future. I hope my voice provides illumination, I do not intend consternation. God has created a world which is here for us to discover. Let's keep at it.
Setterfield: Thank you for your important letter. Your time and effort are appreciated.
However, I think that if you had read my 1987 Report in more detail, it might have become apparent that I had indeed treated each measurement method individually and had drawn the correct conclusions as a result. The Report was built up one Table at a time where all the measured values by a particular method were listed. In that process, it was shown statistically that each measurement method registered a decline in the value of c over time. For example, Table 3 (scroll down a bit) lists only the aberration method results. In fact, I go further. The first Figure in the Report is a graph of the aberration measurements exclusively from the Pulkova Observatory where the same equipment had been used for over a century. The result was a clear decline in the value of c so obtained.
I could go further still. For example, I point out in the Report, that on a number of occasions, apart from Pulkova, the same equipment was used by experimenters at a later date. In each case a lower value for c was recorded on the second occasion. Finally, when all methods are put together, there is still a resultant decline in c.
In this matter, I am intrigued by the fanfare with which it was announced recently that astronomical observations might have indicated a change by one part in 100,000 in the fine-structure constant. However, the more obvious measured changes in c seem to be treated rather dismissively by comparison. I might be rather perverse, but the situation does appeal to my sense of humour!
Under these circumstances, I suggest that a closer reading of the Report would nullify much of your well-intentioned criticism. I trust this answers your concerns.
Questions: What does this mean in plain English? "Time after creation, in orbital years is approximately, D = 1499 t2". You state later that the age of the cosmos is approximately 8000 years (6000 BC + 2000 AD). How is this derived from the formula?
Setterfield: This formula only applies on a small part of the curve as it drops towards its minimum. Note that "D" is atomic time. Furthermore, 't' or orbital time, must be added to 2800 BC to give the actual BC date. The reason for this is that 2800 BC is approximately the time of the light speed minimum.
The more general formula, but still very approximate, is D = 1905t2 + 63,000,000. In this formula, "D" is atomic time. And once the value for "t" has been found it is added to 3005 BC to give the actual BC date. This is done because the main part of the curve starts about 3005 BC when the atomic clock is already registering 63 million years. Working in the reverse, therefore, if we take a date of 5790 BC, we must first subtract 3005. This gives a value for "t" of 2785 orbital years. When 2785 is squared, this gives 7.756 million. This is then multiplied by 1905 to obtain 14.775 billion. From this figure is then subtracted 63 million to give a final figure of 14.71 billion. This is the age in years that would have been registered on the atomic clock of an object formed in 5790 BC.
The minimum value of the speed of light
Two questions were originally posed to Malcolm Bowden in the U.K.
Dear Professor Bowden,
I am presently writing a book entitled, Origin of the Human Species. In one of the later chapters, I am dealing with dating problems, comparing the apparent biblical time frame to that of the standard theory of evolution. I have been aware of Norman and Setterfield's work for some time now and have included a section on c decay and its implications. I just came across your article supporting c decay on the web.
Personally, I am sympathetic to c decay as a solution to my own predilections supporting Adam and Eve! But good science must stand on its own feet. I had included a line citing M.E.J. Gheury de Bray's 1934 findings: I cite particularly his reference to two bits of data: c in 1926 was 299,796 k/s plus or minus 4 k/s and in 1933 was 299,774 k/s plus or minus 1 or 2 k/s. I have deleted the above line because I discovered the present established speed of light to be 299,792.458 k/s.
How can de Bray get a reading in 1933 some 18 k/s below TODAY's reading? Can you help me with this?
Dennis Bonnette, Ph.D.
Chairman,
Philosophy Department
Niagara University, NY 14109
Dear Professor Bowden,
I just came across the following website which I bring to your attention: (URL was garbled) What I found disturbing was a claimed refutation of c decay very near the bottom of this extensive document. It was based on the effect of elevated light speeds in distant celestial objects with respect to our observation here on Earth. The author claims that we would see the objects in "slow motion" because of the c decay as the light rays approached Earth. He claims this is refuted by the consistency of motion of pulsars and other regular objects at great distances. (I hope I have described the issue well enough for you to know what I am talking about or for you to be able to find the text in question on the website.) How would you respond to this claim against c decay? I was most impressed in your own website by the "common sense" argument about the expected distribution of errors as science refines the constant value of a true constant. But I grasp just enough of the abovementioned author's argument to be concerned about it. Your comment would be much appreciated.
Sincerely,
Dennis Bonnette
Response from Malcolm Bowden:
Dear Dr. Bonnette,
Thank you for your email with CDK queries. May I say that I am not a professor! I am a qualified Engineer - Civil and Structural. I regret that I am not a physicist and therefore can have great difficulty in answering technical questions such as you have posed. I have, however, forwarded your queries on to Lambert Dolphin and Barry Setterfield for their far better input. I have given your email address to them so they might reply direct. Lambert Dolphin has a huge website whch has much on CDK on it. You will find it at http://ldolphin.org or via my website. You may find your answer there anyway, but it might take some finding in this large site.
Regarding the de Bray quote, one of the difficulties is what the shape of the curve is. Barry often refers to the Bible verse of "the heavens being stretched out" and one curve is a close fit to a damped oscisllation curve as it decreased. This means is may have overshot the present speed, rose above it and then decreased to the present level. Looking at the graph in my book "True Science Agrees with the Bible" which should be the same as the website one, I see that there are a cluster of readings that are lower than the present speed between 1930 and 1940 and all have very short error bars. None, however, are as much as 18 k/s lower. I am wondering what this reading might be. It is probably one on my graph that has been corrected in some way. This suggests to me that there was another "overshoot" at that time before it settled down to the presen speed. I am forwarding this to Barry and Lambert to see if they have a better explanation than this.
Regarding the pulses from quasars, this is techinical but I agree that there seems to be a problem here. If c is fast, then pulses sent out at 1 sec intervals would travel through space and their speed would gradually slow down. This means that they would arrive at the earth at very long intervals between them. I do not know if there is any easy answer to this so am appealing to the others experts again. On aspect is that on looking into the ways of measuring distance in astronomy, I am very surprised at how much assumptions play a part. It is far from being an exact science! The question is can we be sure that they at vast distances? If they are closer than we think, the light would reach us quite quickly and the problem would be solved because there would not have been vast time periods for the light to slow down.
Certainly, it is the fall in the general readings that is very convincing to me, but there are many ramifications. I may say, that whenever I have a technical query like these two, Barry has always answerd it to my satisfaction - so I have great confidence in his reply to this also. Sorry that I cannot be of greater help but I am awaiting the replies of the greater experts!
Yours in anticipation,
Malcolm Bowden.PS. I think you will be very inrterested in my latest book "True Science agrees with the Bible". Berean Call in USA hold ALL my four books. Tel: 541 382 6210. There is more information about them on my website. In "True" I have set out my own version of the dating periods since creation about 4178 BC.
Response from Barry Setterfield:
Dear Dr. Bonnette,
Yes! There is a "low point" in the measured values of the speed of light, c, in the period 1928-1940. This comprised five different determinations of c by four different experimenters. By 1947 the "low point" was over. The standard establishment view on the problem was that there was a systematic error in the apparatus used. In view of the fact that 4 out of the five values were obtained by Kerr Cells, that explanation MAY have some validity as it involved light going through a polarising liquid. However, the later versions of Kerr Cells were called Geodimeters, and when they were introduced the "low point" was no longer in evidence. But there is another possible explanation.
Malcolm Bowden is absolutely correct when he says that an oscillation is involved in the cDK curve. Take the illustration of a child on a swing. When the swing is pushed, it is responding to a forcing function which may have any period. When the pushes cease, the swing settles down and finally oscillates at its own natural frequency. The complete behaviour of the swing is described mathematically by the two functions, namely the forcing function and the natural oscillation. The same thing is happening with the speed of light. Recent work undergoing peer review at the moment indicates that the general overall function is an exponential decay with a natural period of oscillation imposed upon it. The oscillation has in fact bottomed out in the recent past because evidence from associated constants suggests that c is on the increase again. The oscillation reached its peak around 700 AD.
As for the pulsar problem, most pulsars that have been found are in our own galaxy or within our Local Group of galaxies where the change in c is small. The resultant slow motion effect is therefore going to be minimal, particularly as there is such a wide range in pulsar spin rates. What you described as the potential problem was the expected CHANGE in pulsar spin rates due to dropping values of c in transit. When the calculations are done, the effect is certainly minuscule for Local Group objects.
If I can be of further assistance do not hesitate to let me know. (May 15, 1999).
Comment: It has been suggested that what may have been discovered is not a change in the value of c over the past 100 years, but rather "a secular change in the index of refraction of the atmosphere" due to the industrial revolution.
Setterfield: This issue was discussed in the literature when c was actually measured as varying. In Nature, page 892 for June 13, 1931, V. S. Vrkljan answered this question in some detail. The kernel of what he had to say is this: "...a simple calculation shows that within the last fifty years the index of refraction [of the atmosphere] should have increased by some [6.7 x10-4] in order to produce the observed decrease [in c] of 200 km/sec. According to Landolt-Bornstein (Physikalisch-chemische Tabellen, vol.ii, 1923, p.959, I Erganzungsband, "Tracking or intellectual phase locking and cDK." In another newsgroup postings on this topic, was suggested that the decay in c might be due merely to "tracking" or intellectual phase locking. This process is described as one in which the values of a physical constant become locked around a canonical value obtained by some expert in the field. Because of the high regard for the expert, other lesser experimenters will tailor their results to be in agreement with the value obtained by the expert. As a result, other experiments to determine the value of the constant will only slowly converge to the correct value.
Although this charge may be levelled at some high school and first year university students, it is an accusation of intellectual dishonesty when brought into the arena of the cDK measurements. First, there was a continuing discussion in the scientific literature as to why the measured values of c were decreasing with time. It was a recognised phenomena. In October of 1944, N. E. Dorsey summarised the situation. He admitted that the idea of c decay had "called forth many papers." He went on to state that "As is well-known to those acquainted with the several determinations of the velocity of light, the definitive values successively reported ... have, in general, decreased monotonously from Cornu's 300.4 megametres per second in 1874 to Anderson's 299.776 in 1940 ..." Dorsey strenuously searched for an explanation from the journals that the various experimenters had kept of their determinations. All he could do was to extend the error limits and hope that this covered the problem. In Nature for April 4, 1931, Gheury de Bray commented: "If the velocity of light is constant, how is it that, INVARIABLY, new determinations give values which are lower than the last one obtained. ... There are twenty-two coincidences in favour of a decrease of the velocity of light, while there is not a single one against it." (his emphasis).
In order to show the true situation, one only has to look at the three different experiments that were running concurrently in 1882. There was no collusion between the experimenters either during the experiments or prior to publication of their results. What happened? In 1882.7 Newcomb produced a value of 299,860 km/s. In 1882.8 Michelson produced a value of 299,853 km/s. Finally in 1883, Nyren obtained a value of 299,850 km/s. These three independent authorities produced results that were consistent to within 10 km/sec. This is not intellectual phase locking or tracking; these are consistent yet independent results from three different recognised authorities. Nor is this a unique phenomenon. Newcomb himself noted that those working independently around 1740 obtained results that were broadly in agreement, but reluctantly concluded that they indicated c was about 1% higher than in his own time. In 1941 history repeated itself when Birge made a parallel statement while writing about the c values obtained by Newcomb, Michelson and others around 1880. Birge was forced to concede that "...these older results are entirely consistent among themselves, but their average is nearly 100 km/s greater than that given by the eight more recent results."
In view of the fact that these experimenters were not lesser scientists, but were themselves the big names in the field, they had no canonical value to uphold. They were themselves the authorities trying to determine what was happening to a capricious "constant". The figures from Michelson tell the story here. His first determination in 1879 gave a value of 299,910 km/s. His second in 1883 gave a result of 299,853 km/s. In 1924 he obtained a value of 299,802 km/s while in 1927 it was 299,798 km/s. This is not intellectual phase locking. Nor is it typical of a normal distribution about a fixed value. What usually happens when a fixed constant is measured is that the variety of experiments give results that are scattered about a fixed point. Instead, when all the c results are in, there is indeed a scatter; yet that scatter is not about a fixed point, but about a declining curve. It is a phenomenon that intellectual phase locking cannot adequately explain. If Dorsey, Birge or Newcomb could have explained it that way, we would certainly have heard about it in the scientific literature of the time. (May 20, 1999)
Why is c not measured as changing now?
Question: Since about 1960 the speed of light has been measured with tremendous precision with no observed change. Proponents of cDK usually reply that we have redefined units of measurement in such a way that when the modern methods of measurement are used the change in c disappears because of cancellation. Has anyone attempted to remeasure c by "old fashioned" methods? It would seem to me that redoing the classic measurements could settle this issue, at least to my satisfaction. This would provide a new baseline of at least four decades, and probably much more.
Setterfield: The problem with current methods of light-speed measurements (mainly laser) is that both wavelengths [W] and frequency [F] are measured to give c as the equation reads [c = FW]. If you have followed the discussion well, you will be aware that, within a quantum interval, wavelengths are invariant with any change in c. This means that it is the frequency of light that varies lock-step with c. Unfortunately, atomic frequencies also vary lock-step with c, so that when laser frequencies are measured with atomic clocks no difference will be found.
The way out of this is to use some experimental method where this problem is avoided. It has been suggested that the Roemer method may be used. This method uses eclipse times of Jupiter's inner satellite Io. Indeed it has been investigated by Eugene Chaffin. Although many things can be said about his investigation (and they may be appropriate at a later date), there are a couple of outstanding problems which confronts all investigators using that method. Chaffin pointed out that perturbations by Saturn, and resonance between Io, Europa, and Ganymede are definitely affecting the result, and a large number of parameters therefore need investigation. Even after that has been done, there remains inherent within the observations themselves a standard deviation ranging from about 30 to 40 seconds. This means the results will have an intrinsic error of up to 24,000 km/s. Upon reflection, all that can be said is that this method is too inaccurate to give anything more than a ball-park figure for c, which Roemer to his credit did, despite the opposition. It therefore seems unwise to dismiss the cDK proposition on the basis of one of the least precise methods of c measurement as the notice proposes that was brought to our attention. This leaves a variety of other methods to investigate.
However, that is not the only way of determining what is happening to c. There are a number of other physical constants which are c-dependent that overcome the problem with the use of atomic clocks. One of these is quantised Hall Resistance now called the von Klitzing constant. Another might be the gyromagnetic ratio. A further method is to compare dynamical intervals (for example, using Lunar radar or laser ranging) with atomic intervals. These and other similar quantities give an indication that c may have bottomed out around 1980 and is slowly increasing again. Indeed, atomic clock comparisons with historical data can be used to determine the behaviour of c way back beyond 1675 AD when Roemer made the first determination. These data seem to indicate that c reached a maximum around 700 AD (very approximately). The data from the redshift paper implies that this oscillation is superimposed on an exponential decline in the value of c from the early days of the cosmos. A more complete discussion appears in the Redshift paper. In other words, whole new sets of data are becoming available from additional sources that allow the original proposition to be refined. I trust that you find this helpful. (May 20, 1999).
Comment: I was thinking more in terms of a Fizzeau device, which is what I assumed was used by Newcomb and the others mentioned in your earlier comments.
Setterfield: Your suggestion is a good one. Either the toothed wheel or the rotating mirror experiments should give a value for c that is free from the problems associated with the atomic clock/frequency blockage of modern methods, and the shortcomings of the Roemer method. The toothed wheel requires a rather long base-line to get accurate results as shown by the experiments themselves. However, given that limitation, an interesting feature may be commented upon. Cornu in 1874.8 and Perrotin in 1901.4 essentially used the same equipment. The Cornu mean is 299,945 km/s while the Perrotin mean is 299,887 km/s. This is a drop of 58 km/s in 26.6 years measured by the same equipment.
The rotating mirror experiments also required a long base-line, but the light path could be folded in various ways. Michelson in 1924 chose a method that combined the best features of both the rotating mirror and toothed wheel: it was the polygonal mirror. In the 1924 series, Michelson used an octagonal mirror. Just over two years later, in 1926.5 he decided to use a variety of polygons in a second series of experiments. The glass octagon gave 299,799 km/s; the steel octagon 299,797 km/s; a 12 faced prism had 299,798 km/s; a 12 faced steel prism gave 299,798 km/s; and a 16 faced glass prism resulted in a value of 299,798 km/s. In other words all the polygons were in agreement to within +/-- 1 km/s and about 1,600 individual experiments had been performed. That is a rather impressive result. However, despite the internal accuracy to within 1 km/s, these results are still nearly 6.5 km/s above the currently accepted value.
To my way of thinking, this polygonal mirror method would probably be the best option for a new determination of c. On the other hand, perhaps Newcomb's or Michelson's apparatus from earlier determinations may still be held in a museum display somewhere. Modern results from such apparatus would certainly arouse interest. Thanks for the helpful suggestion.
Questions: Are you saying that 'c' is no longer decaying? (assuming the velocity of light has decreased exponentially to nearly zero at the present time.) Do you mean "nearly zero" compared to what it may have been at the time of creation?
Setterfield: The exponential decay has an oscillation superimposed upon it. The oscillation only became prominent as the exponential declined. The oscillation appears to have bottomed out about 1980 or thereabouts. If that is the case (and we need more data to determine this exactly) then light-speed should be starting to increase again. The minimum value for light-speed was about 0.6 times its present value. This is as close to 'zero' as it came.
addition September 5, 2003:
Question: I have been thinking about the speed of light's exponential decrease, and it seems to me that soon there will be a point in time when the speed of light will stop decreasing altogether, and either become a constant or maybe it will bounce back a little bit, like the recoil of a rubber band as it's let go.
What do you think of this idea? And can you work out what year the speed of light would reach a zero point of deceleration, based on your deceleration curve?
Setterfield: First of all, the decrease in the speed of light is not strictly exponential, although it does follow a well-defined mathematical curve. There is an extremely fast drop at first, which then tapers off similar to a Lorentzian curve. Will it ever cease decreasing? Yes, possibly. But, as you mention, there is a recoil effect which we have picked up in the redshift measurements and which has also been picked up in recent light speed measurements. The minimum light speed appeared to be reached, actually, around 1980, and there is evidence of a slight increase since then. You can see evidence of this in the last two graphs here.
When you check the dates for both Planck’s Constant and the mass graph, you will see a slight change about 1980. Although the speed of light graph does not go this far in time, as I was just showing Birge’s accepted values, it would show the same slight change in direction at this time as well. The change you do see in the light speed graph around 1940 appears to be somewhat anomalous, as this same ‘burp’ can be seen during the same years in the lower two graphs as well.
On the Measurement of Time, and the Velocity of Light
Setterfield: Several questions have been raised which deserve a reply.
First, the matter of timing and clocks. In 1820 a committee of French scientists recommended that day-lengths throughout the year be averaged, to what is called the mean solar day. The second was then defined as 1/86,400 of this mean solar day. This definition was accepted by most countries and supplied science with an internationally accepted standard of time. This definition was used right up until 1956. In that year it was decided that the dynamical definition of a second be changed to become 1/31,556,925.97474 of the earth's orbital period that began at noon on the 1st January 1900. Note that this definition of the second ensured that the second remained the same length of time as it had always been right from its earlier definition in 1820. This definition continued until 1967 when atomic time became standard. The point to note is that in 1967 one second on the atomic clock was DEFINED as being equal to the length of the dynamical second, even though the atomic clock is based on electron transitions. Interestingly, the vast majority of c measurements were made in the period 1820 to 1967 when the actual length of the second had not changed. Therefore, the decline in c during that period cannot be attributed to changes in the definition of a second.
However, changes in atomic clock rates affecting the measured value for c will certainly occur post 1967. In actual fact, the phasing-in period for this new system was not complete until January 1, 1972. It is important to note that dynamical or orbital time is still used by astronomers. However, the atomic clock which astronomers now use to measure this has leap-seconds added periodically to synchronise the two clocks. The International Earth Rotation Service (IERS) regulates this procedure. Since January 1st, 1972, until January 1st, 1999 exactly 32 leap seconds have been added to keep the two clocks synchronised. There are a number of explanations as to why this one-sided procedure has been necessary. Most have to do with changes in the earth's rotational period. However, a contributory cause MAY be the change in light-speed, and the consequent change in run-rate of the atomic clock. If it is accepted that it is the run-rate of the atomic clock which has changed by these 32 seconds in 27 years, then this corresponds to a change in light-speed of exactly [32/(8.52032 x 108) c = (3.7557 x 10-8 c ] or close to 11.26 metres/second.
The question then becomes, "Is this a likely possibility?" Many scientists would probably say no. However, Lunar and planetary orbital periods which comprise the dynamical clock, have been compared with atomic clocks from 1955 to 1981 by Van Flandern and others. Assessing the evidence in 1981 Van Flandern noted that "the number of atomic seconds in a dynamical interval is becoming fewer. Presumably, if the result has any generality to it, this means that atomic phenomena are slowing down with respect to dynamical phenomena." (Precision Measurements and Fundamental Constants II, pp. 625-627, National Bureau of Standards (US) Special Publication 617, 1984. Even if these results are controversial, Van Flandern's research at least establishes the principle on which the former comments were made.
Note here that, given the relationship between c and the atomic clock, it can be said that the atomic clock is extraordinarily PRECISE as it can measure down to less than one part in 10 billion. However, even if it is precise, it may not be ACCURATE as its run-rate will vary with c. Thus a distinction has to be made between precision and accuracy when talking about atomic clocks.
Finally, there were some concerns about timing devices used on any future experiments to determine c by the older methods. Basically, all that is needed is an accurate counter that can measure the number of revolutions of a toothed wheel or a polygonal prism precisely enough in a one second period while light travels over a measured distance. Obviously the higher the number of teeth or mirror faces the more accurate the result. Fizeau in 1849 had a wheel with 720 teeth that rotated at 25.2 turns per second. In 1924, Michelson rotated an octagonal mirror at 528 turns per second. We should be able to do better than both of those now and minimise any errors. The measurement of the second could be done with accurate clocks from the mid-50's or early 60's. This procedure would probably overcome most of the problems that John foresees in such an experiment. If John has continuing problems, please let us know.
Further Comments on Time Measurements and c: In 1820 a committee of French scientists recommended that day lengths throughout the year be averaged, to what is called the Mean Solar Day. The second was then defined as 1/86,400 of this mean solar day. This supplied science with an internationally accepted standard of time. This definition was used right up to 1956. In that year it was decided that the definition of the second be changed to become 1/31,556,925.97474 of the earth's orbital period that began at noon on 1st January 1900. This definition continued until 1967 when atomic time became standard. In 1883 clocks in each town and city were set to their local mean solar noon, so every individual city had its own local time. It was the vast American railroad system that caused a change in that. On 11th October 1883, a General Time Convention of the railways divided the United States into four time zones, each of which would observe uniform time, with a difference of precisely one hour from one zone to another. Later in 1883, an international conference in Washington extended this system to cover the whole earth.
The key point to note here is that the vast majority of c measurements were made during the period 1820 to 1956. During that period there was a measured change in the value of c from about 299,990 km/s down to 299,792 km/s, a drop of the order of 200 km/s in 136 years. The question is what component of that may be attributable to changes in the length of the second since the rate of rotation of the earth is involved in the existing definition. It is here that the International Earth Rotation Service (IERS) comes into the picture. Since 1st January 1972 until 1st January 1999, exactly 32 leap seconds have been added to keep Co-ordinated Universal Time (UTC) synchronised with International Atomic Time (TAI) as a result of changes in the earth's rotation rate. Let us assume that these 32 leap seconds in 27 years represent a good average rate for the changes over the whole period of 136 years from 1820 to 1956. This rate corresponds to an average change in measured light-speed of [32/(8.52023 x 108) c = (3.7557 x 10-8) c] or close to 11.26 metres per second in one year. As 136 years are involved at this rate we find that [11.26 x 136 = 1531] metres per second or 1.53 km/s over the full 136 years. This is less than 1/100th of the observed change in that period. As a result it can be stated (as I think Froome and Essen did in their book "The Velocity of Light and Radio Waves") that limitations on the definition of the second did not impair the measurement of c during that period ending in 1956.
Therefore, if measurements of c were done with modern equivalents of rotating mirrors, toothed wheels or polygonal prisms, and the measurements of seconds were done with accurate equipment from the 1950's, a good comparison of c values should be obtained. Note, however, that the distance that the light beam travels over should be measured by equipment made prior to October 1983. At that time c was declared a universal constant (299,792.458 km/s) and, as such, was used to re-define the metre in those terms.
As a result of the new definitions from 1983, a change in c would also mean a change in the length of the new metre compared with the old. However, this process will only give the variation in c from the change-over date of 1983. By contrast, use of some of the old experimental techniques measuring c will allow direct comparisons back to at least the early 1900's and perhaps earlier. In a similar way, comparisons between orbital and atomic clocks should pick up variations in c. As pointed out before, this latter technique has in fact been demonstrated to register changes in the run-rate of the atomic clock compared with the orbital clock by Van Flandern in the period 1955 to 1981.
By way of further information, the metre was originally introduced into France on the 22nd of June, 1799, and enforced by law on the 22nd of December 1799. This "Metre of the Archives" was the distance between the end faces of a platinum bar. In September 1889 up till 1960 the metre was defined as the distance between two engraved lines on a platinum-iridium bar held at the International Bureau of Weights and Measures in Sevres, France. This more recent platinum-iridium standard of 1889 is specifically stated to have reproduced the old metre within the accuracy then possible, namely about one part in a million. Then in 1960, the metre was re-defined in terms of the wavelength of a krypton 86 transition. The accuracy of lasers had rendered a new definition necessary in 1983. It can therefore be stated that from about 1800 up to 1960 there was no essential change in the length of the metre. It was during that time that c was measured as varying. As a consequence, the observed variation in c can have nothing to do with variations in the standard metre. (May 29, 1999)
Question: Barry points out that for obvious reasons no change in the speed of light has been noticed since the redefinition of time in terms of the speed of light a few decades ago. However, the new definition of time should cause a noticeable drift from ephermis time due to the alleged changing speed of light. I'm not aware of any such drift. Ephemeris time should be independent of the speed of light. Before atomic standards were adopted, crystal clocks had documented the irregular difference between ephemeris time and time defined by the rotation of the earth. Has Barry investigated this?
Setterfield: On the thesis being presented here, the run-rate of atomic clocks is proportional to 'c'. In other words, when 'c' was higher, atomic clocks ticked more rapidly. By contrast, it can be shown that dynamical, orbital or ephemeris time is independent of 'c' and so is not affected by the 'c' decay process. Kovalevsky has pointed out that if the two clock rates were different, "then Planck's constant as well as atomic frequencies would drift" [J. Kovalevsky, Metrologia 1:4 (1965), 169].
Such changes have been noted. At the same time as 'c' was measured as decreasing, there was a steady increase in the measured value of Planck's constant, 'h', as outlined in the 1987 Report by Norman and Setterfield. However, the measured value of 'hc' has been shown to be constant throughout astronomical time. Therefore it must be concluded from these measurements that 'h' is proportional to 1/c precisely. As far as different clock rates is concerned, the data is also important. During the interval 1955 to 1981 Van Flandern examined data from lunar laser ranging using atomic clocks and compared them with dynamical data. He concluded that: "the number of atomic seconds in a dynamical interval is becoming fewer. Presumably, if the result has any generality to it, this means that atomic phenomena are slowing down with respect to dynamical phenomena" [T. C. Van Flandern, in 'Precision Measurements and Fundamental Constants II,' (B. N. Taylor and W. D. Phillips, Eds.), NBS (US), Special Publication 617 (1984), 625]. These results establish the general principle being outlined here. Van Flandern also made one further point as a consequence of these results. He stated that "Assumptions such as the constancy of the velocity of light · may be true only in one set of units (atomic or dynamical), but not the other" [op. cit.]. This is the kernel of what has already been said above. Since the run-rate of the atomic clock is proportional to 'c', it becomes apparent that 'c' will always be a constant in terms of atomic time. Van Flandern's measurements, coupled with the measured behaviour of 'c', and other associated 'constants', indicate that the decay rate of 'c' was flattening out to a minimum which seemed to be attained around 1980. Whether or not this is the final minimum is a matter for decision by future measurements. But let me explain the situation this way. The astronomical, geological, and archaeological data indicate that there is a ripple or oscillation associated with the main decay pattern for 'c'. In many physical systems, the complete response to the processes acting comprises two parts: the particular or forced response, and the complimentary, free, or natural response. The forced response gives the main decay pattern, while the free response often gives an oscillation or ripple superimposed on the main pattern. The decay in 'c' is behaving in a very similar way to these classical systems.
There are three scenarios currently undergoing analysis. One is similar to that depicted by E. A. Karlow in American Journal of Physics 62:7 (1994), 634, where there is a ripple on the decay pattern that results in "flat points", following which the drop is resumed. The second and third scenarios are both presented by J. J. D'Azzo and C. H. Houpis "Feedback Control System Analysis and Synthesis" International Student Edition, p.258, McGraw-Hill Kogakusha, 1966. In Fig. 8-5 one option is that the decay with its ripple may bottom out abruptly and stay constant thereafter. The other is that oscillation may continue with a slight rise in the value of the quantity after each of the minima. Note that for 'c' behaviour, the inverse of the curves in Fig. 8-5 is required. All three options describe the behaviour of 'c' rather well up to this juncture. However, further observations are needed to finally settle which sort of curve is being followed. (March 26, 2001).
Light Speed and the Early Cosmos (Barry Setterfield, January 24, 2002)
The issue of light-speed in the early cosmos is one which has received some attention recently in several peer-reviewed journals. Starting in December 1987, the Russian physicist V. S. Troitskii from the Radiophysical Research Institute in Gorky published a twenty-two page analysis in Astrophysics and Space Science regarding the problems cosmologists faced with the early universe. He looked at a possible solution if it was accepted that light-speed continuously decreased over the lifetime of the cosmos, and the associated atomic constants varied synchronously. He suggested that, at the origin of the cosmos, light may have traveled at 1010 times its current speed. He concluded that the cosmos was static and not expanding.
In 1993, J. W. Moffat of the University of Toronto, Canada, had two articles published in the International Journal of Modern Physics D. He suggested that there was a high value for 'c' during the earliest moments of the formation of the cosmos, following which it rapidly dropped to its present value. Then, in January 1999, a paper in Physical Review D by Andreas Albrecht and Joao Magueijo, entitled "A Time Varying Speed Of Light As A Solution To Cosmological Puzzles" received a great deal of attention. These authors demonstrated that a number of serious problems facing cosmologists could be solved by a very high initial speed of light.
Like Moffat before them, Albrecht and Magueijo isolated their high initial light-speed and its proposed dramatic drop to the current speed to a very limited time during the formation of the cosmos. However, in the same issue of Physical Review D there appeared a paper by John D. Barrow, Professor of Mathematical Sciences at the University of Cambridge. He took this concept one step further by proposing that the speed of light has dropped from the value proposed by Albrecht and Magueijo down to its current value over the lifetime of the universe.
An article in New Scientist for July 24, 1999, summarised these proposals in the first sentence. "Call it heresy, but all the big cosmological problems will simply melt away, if you break one rule, says John D. Barrow - the rule that says the speed of light never varies." Interestingly, the initial speed of light proposed by Albrecht, Magueijo and Barrow is 1060 times its current speed. In contrast, the redshift data give a far less dramatic result. The most distant object seen in the Hubble Space Telescope has a redshift, 'z', of 14 (see note). This indicates light-speed was about 9 x 108 greater than now. At the origin of the cosmos this rises to about 2.5 x 1010 times the current value of c, more in line with Troitskii's proposal, and considerably more conservative than the Barrow, Albrecht and Magueijo estimate. This lower, more conservative estimate is also in line with the 1987 Norman-Setterfield Report.
note: April 2, 2003. Shortly after these high redshifts were announced, further analysis was done and it was found that data had been misinterpreted: what had happened was that these objects being noted with this redshift were actually very red objects which were much closer to us than had been expected. The current most distant redshift is below z=7.
http://www.sciencedaily.com/releases/1999/10/991005114024.htm
Published: 10-6-1999 Author: Bruce Rolston
Speed Of Light May Not Be Constant, Physicist Suggests
A University of Toronto professor believes that one of the most sacrosanct rules of 20th-century science -- that the speed of light has always been the same - is wrong. Ever since Einstein proposed his special theory of relativity in 1905, physicists have accepted as fundamental principle that the speed of light -- 300 million metres per second -- is a constant and that nothing has, or can, travel faster. John Moffat of the physics department disagrees - light once travelled much faster than it does today, he believes.
Recent theory and observations about the origins of the universe would appear to back up his belief. For instance, theories of the origin of the universe -- the "Big Bang"- suggest that very early in the universe's development, its edges were farther apart than light, moving at a constant speed, could possibly have travelled in that time. To explain this, scientists have focused on strange, unknown and as-yet-undiscovered forms of matter that produce gravity that repulses objects.
Moffat's theory - that the speed of light at the beginning of time was much faster than it is now - provides an answer to some of these cosmology problems. "It is easier for me to question Einstein's theory than it is to assume there is some kind of strange, exotic matter around me in my kitchen." His theory could also help explain astronomers' discovery last year that the universe's expansion is accelerating. Moffat's paper, co-authored with former U of T researcher Michael Clayton, appeared in a recent edition of the journal Physics Letters.
Questions: I'm not a scientist, although I have some math and science background, and I am only just beginning to look into this discussion and may be asking a stupid question. Apology stated. I am a fellow believer and view Genesis as the ultimate "Theory" for which we need to find proof (not that we need to defend God, but it seems a reasonable part of our witness). That said, I want to review the emerging theories somewhat objectively. I noticed in Setterfield's paper there was reference to conservation of energy E=MC2. I found it interesting that VSL theory put forth by Magueijo doesn't require that, but seems to say energy will not be conserved with time. Have Setterfield (or yourself) reviewed the work of Magueijo? Perhaps he has discovered something important. Ultimately any theory has to make since on an earth populated by humans to be of any use to us. Does this consideration require conservation of energy in the Setterfield theory? Or, is it possible that energy may not be conserved over the history of the universe?
Setterfield: Yes, we certainly have considered Albrecht and Magueijo's paper and are aware of what he is proposing. His paper is basically theoretical and has very little observational backing for it. By contrast, my papers are strictly based on observational evidence. This requires that there is conservation of energy. The observational basis for these proposals also reveals that there is a series of energy jumps occurring at discrete intervals throughout time as more energy becomes available to the atom. Importantly, it should be noted that this energy was initially invested in the vacuum during its expansion, and has become progressively available as the tension in the fabric of space has relaxed over time thus converting potential energy into the kinetic energy utilised by the atom. The atom can only access this energy once a certain threshold has been reached, and hence it occurs in a series of jumps. This has given rise to the quantised redshift that occurs in space.
Thus observational evidence agrees with the conservation approach rather than Mageuijo's approach. (1/31/01)
see also Einstein's Biggest Blunder -- transcript of an interview with Albrecht and Magueijo
Setterfield: On Thursday 8th August 2002, a burst of Press publicity accompanied the publication of a paper in the prestigious scientific journal Nature. That article was authored by Professor Paul Davies, of Sydney's Macquarie University, and by two astrophysicists from the University of New South Wales, Dr. Charles Lineweaver, and graduate student Tamara Davis. The paper suggested that the speed of light was much higher in the past and had dropped over the lifetime of the universe. These conclusions were reached as a result of the observations of University of New South Wales astronomer Dr. John Webb made in 1999 and the more recent observations of one of his PhD students, Michael Murphy. These observations indicated a slight shift in the position of the dark lines that appear in the rainbow spectrum of metallic atoms deep in space when compared with their expected position. Because there are a number of factors to disentangle statistically, and because the effect is small (about 1 part in 100,000), there remains some doubt as to the validity of the primary conclusion, let alone the suspected causes of the effect.
The actual physical quantity that the observations are targeting is the fine structure constant. This constant links together four other atomic quantities, namely the speed of light, the electronic charge, Planck's constant and the electric property of free space called the permittivity. It is possible that any one of these quantities may be varying, or that there is synchronous variation between some or all of the components that make up the fine structure constant. Thus, one possible explanation for the observed effect is that the speed of light was higher the further back in time we look. But it is not the only explanation. Other possible explanations include a change in the value of the charge on the electron. However, the paper by Davies et al. rejects this possibility on the basis of what was expected to occur with black holes at the frontiers of the cosmos. Until I have seen a copy of the paper by Davies et al. I do not know if they have eliminated all other options.
However, since a major paper by Andreas Albrecht and Jao Magueijo in 1999, and another one by John Barrow in the same issue of Physical Review D, the speed of light has come under increasing scrutiny as a physical quantity that may be varying. These scientists are saying that if lightspeed was significantly higher at the inception of the cosmos (about 1060 higher) then a number of astronomical problems can be readily resolved. Paul Davies statements echo that and he, like Barrow, considers that lightspeed has declined over the history of the universe. By contrast, Albrecht and Magueijo contained the lightspeed change to the earliest moments of the Big Bang and had it drop to its present value immediately afterwards. In that sense, this recent work is consolidating the belief that the drop in lightspeed has extended over the whole history of the universe. This is the position that the variable lightspeed (Vc) research has advocated since the early 1980's.
The cause of the change in the speed of light has still to be determined, but according to Lineweaver, one of the prime suspects is that the structure of the vacuum has been changing uniformly across the cosmos. This is also the position that the Vc research has advocated since the early to mid- 1990's and was formalised in Atomic Quantum States, Light and the Redshift. It is also the key subject of "Exploring the Vacuum." Because there is an intrinsic energy in every cubic centimetre of the vacuum, this energy may manifest as virtual particle pairs like electron/positron pairs that flit in and out of existence. As a photon of light travels through the vacuum, it hits a virtual particle, is absorbed, and then shortly after is re-emitted. This process, while fast, still takes a finite time to occur. Thus, a photon of light is like a runner going over hurdles. The more hurdles over a set distance on the track the longer it takes for runners to reach their destination. Thus, if the energy content of space increased with time, more virtual particles would manifest per unit distance, and so the longer light would take to reach its destination.
Much was made of the potential problems that lightspeed changes would cause to Einstein's theory of Relativity. This matter has been discussed ever since Albrecht and Magueijo's paper in 1999. However, the Vc work examined this issue back in the 1980's and decided that Einstein's work will basically remain valid provided that energy is conserved in the process. This necessarily involves changes in a number of other constants as Trevor Norman and I outlined in the 1987 Report, The Atomic Constants, Light and Time, from SRI International and Flinders University. These matters are also discussed in further detail in the 2001 paper. I also had the opportunity to briefly pursue the issue of observed changes to other atomic constants with Prof. Albrecht in March 2002. He admitted that his proposal had problems with the observations of some constants. I mentioned that these problems could be overcome if energy was conserved in the process. He stated that they had looked at that but decided that they could not achieve all the effects they wanted to if energy was conserved, and so abandoned that position. Albrecht and Magueijo attempted to largely avoid these problems by isolating lightspeed changes to the earliest moments of the Big Bang. However, these more recent results are tending to confirm that the change has been occurring over the lifetime of the universe. Consequently, the issue of changing atomic constants must be opened again, and the validity of Einstein's equations linked in with it.
In summary, the scientific community is coming to believe that a drop in lightspeed has occurred over the lifetime of the cosmos from some initial value near 1060 times its current speed. The Vc research has indicated that lightspeed has been dropping over the life of the universe from a maximum value around 1011 times now. This is a more conservative estimate than others are proposing. The actual cause of the change in lightspeed is suspected by both secular scientists and those involved in the Vc research as being related to changes in the structure of the vacuum. Finally, Einstein's equations have been called into question. However, they can be shown to be basically correct provided that energy is conserved in the process of c variation, but some other atomic constants will vary synchronously in this case. Those other constants, which have been shown to be varying in this way from observational data, were examined in the 1987 Report and the 2001 paper and support the Vc position.
10th August 2002.
Related reference: Speed of Light Slowing Down After All? by Carl Wieland, 8/9/02.
There are a number of pages on the web critical of the Setterfield work. As time permits, responses to these will be posted below. See also General Objections
Response to Robert Day of Talk.origins
A Response to Joseph Meert (Helen Setterfield)
Supportive and Explanatory Essays by others
Speed of Light Slowing Down? by Chuck Missler
Expanded explanation and implications regarding a changing c by Lambert Dolphin
Reports of the Death of Speed of Light Decay are Premature, by Malcolm Bowden
The Decrease in the Speed of Light -- an Update on Developments, by Malcolm Bowden
The Decay of the Speed of Light, by James P. Dawson