KARL JASPERS FORUM
Response 9 (to Raman, C17, Beamish, C18, and Boyd, C19)
THE SPEED OF
LIGHT AND PEOPLE :
FINDING VERSUS STANDARD
by Herbert FJ Müller
16 April 2008, posted 26 April 2008
I am much obliged for the commentaries by VV Raman (C17), P Beamish (C18), and RN Boyd (C19), concerning my question (in R6) about the speed of light. I am aware that my interests may appear naive to those whose work is or has been in theoretical physics, since my knowledge of this field is rudimentary; but since I am now retired from work, I will take that risk.
Raman is certainly right in saying that problems in physics cannot be solved by discussion alone (C17<10>); but one might add that neither can they be addressed by experimentation alone without clarification of concepts. The history of theoretical physics since 1900 has been characterized by conceptual problems, discussions have been intense, and some of the most prominent physicists have felt a need to write extensively about ‘reality’ – something which concerns everybody. Should the rest of us be confined to be passive bystanders and let the authorities tell us what to think ? The differences of opinion in the commentaries have helped me to improve (I hope) my questions on the topic of the speed of light.
Let me start by saying what I am not, and what I am, after. I do not want to doubt the effectiveness of relativity theory (C17 <10>), which seems to be confirmed every time it is put to the test, compared to predictions based on the earlier naϊve-realistic space-time assumptions. I do want to address some conceptual aspects of this theory, specifically the role of the subject(s) in it, which, considering Einstein’s 1905 paper on (special) relativity, might profit from discussion; this prompts as well the incidental observation that physicists use the term ‘speed of light’ in two different though related meanings : as finding or as standard.
The reason for my question is my interest in epistemology, which in turn stems from the wish to deal with the - otherwise so far unsolved - conceptual problem of the mind-brain relationship (see my TA45 in KJF and related papers). It has led me to formulate a view which rejects the idea of MIR : that reality is mind-independently pre-structured, as proposed by traditional metaphysics, which is for instance implied in subject-exclusive objectivity. The reason for the rejection is that by definition MIR-belief eliminates the mind from reality (and in addition one could know nothing about MIR). The start-point of my ‘zero-derivation’ (0-D) view, which is needed to address this question, is that all mental structures (dealing with mind, world, and everything) are created as working-tools within ongoing experience which, as Jaspers emphasized, encompasses all mental structures. Mental structures always include the subject, both singular and plural, and are not derived from any pre-existing structures outside experience. Since it is not likely that there can be more than one viable epistemology, I am now in the process of testing this 0-D view in various areas other than the mind-brain question.
1905 AND PEOPLE
The difficulty, as I see it, is that Einstein described his ideas in subject-exclusive terms. Although he mentions the observer repeatedly in his 1905 paper on special relativity, he does it in the sense that the observer is ‘attached to’ or ‘equipped with’ pre-existing structures, like to the origin of a coordinate system, with a clock, or with a measuring-stick. These structures are commonly interpreted as being mind-independent (MIR) entities, and were apparently also seen in this way by Einstein.
In the introduction to his paper (see appendix below) Einstein postulated that the speed of light does not depend on the speed of the emitting body; this is in agreement with the finding that light from a star is perceived to have the same speed whether the earth approaches it or recedes from it. He did not raise the question whether or not the speed of light is constant with respect to the persons who measure it; actually in the introduction he did not mention observers at all. But later on in the paper the reason for this omission, and Einstein’s opinion about subjects, become clearer; he wanted to get rid of them (as it is a goal in all subject-exclusive objective science, corresponding to Thomas Nagel’s ‘view from nowhere’) :
In §1, Einstein defined ‘simultaneity’. Here is his first mention of the observer : he wrote ‘we could be satisfied with evaluating the events ... by having an observer ... coordinate a received light-signal with ... a clock position ...’ but adds that this has the ‘Übelstand’ that it [the coordination] is not independent of the point of view of the observer who is equipped with the clock. [‘Übelstand’ is an ‘unfortunate situation’; ‘übel’ is etymologically = the English word ‘evil’, though the meaning in German is usually less strong than ‘wicked’. The English translation of the paper puts it more mildly : ‘But this co-ordination has the disadvantage that it is not independent of the standpoint of the observer with the watch or clock ...’ ]
This and similar examples in the 1905 paper on relativity suggest that the subject’s role has been purposely eliminated from consideration. This interpretation is also in accordance with other manifestations of Einstein’s traditional metaphysical (i.e., mind-independent reality) view, for instance in his discussions with Niels Bohr.
A subject-inclusive view does not interfere with the definition of simultaneity as given in §1. This procedure is a tool within encompassing experience. The practical problem with the observer-mediated coordination is not the presence of the observer per se, but the human reaction time, which entirely prevents the ‘coordination’ procedure by an observer. Einstein did not mention this point; he was concerned not with the practical problem, but with the principle of subject-exclusion.
SOME QUESTIONS AND TENTATIVE ANSWERS, FOR DISCUSSION
Findings versus postulates
As mentioned above, in the 0-D view all mental structures arise within ongoing experience, and include the subject(s). The speed of light is measured by people, and therefore in relation to people, including for instance to their location and movement. And as Boyd points out (C19<1>ff), the absoluteness of the constancy of light (as advocated by Beamish, C18<7>) is a mathematical convenience (or postulate, in Einstein’s term) rather than being an empirically correct finding. (Boyd presents several additional points, for which it would be of interest to have a discussion by those who are well informed; they include, among others, the possibility of supra-luminal speeds, and a late self-critique by Einstein, concerning relativity theory.)
If indeed the constancy of light is a (deliberate) mathematical convenience, that fact underscores Einstein’s formulation in the introduction that he has ‘introduced’ the constancy of V (or of c in the English translation; ‘c’ is the symbol used since the 1920s) as a ‘postulate’. He did that, as he said, ‘in order to arrive at a simple theory for the electrodynamics of moving bodies’. If one keeps c constant, its constituent concepts ‘time’ and ‘space’ will under the new convention be deformed when the transmission of light is interfered with - for instance by gravitation.
But this does not imply a revised ‘ontology’, as it is implied for instance results in mysterious MIR-statements such as that ‘space IS deformed’. The only effect of such pronouncements is to boggle the naϊve-realist mind. In the 0-D view all mental structuring tools, specific as well as holistic, arise (and are corrected) as required. Both the notions of absolute time and space, and the one of absolute speed of light, can only be holistic working-tools within encompassing experience.
Two functions of c
My present understanding of Einstein’s proposition is that he used the constancy of (V or) c as a new fixed anchor point in his theory; it replaced the previously employed, but now discarded, naϊve-realist anchor point of absolute rest (implying absolute space and time), which had been entirely ad-hoc and fictitious, but nevertheless worked well enough as an imaginary fixed reference, e.g., for clocks and co-ordinate systems, until about 1900. In that respect relativity theory is also similar to other more general ad-hoc stabilizers, as used in religion and other fields (cf. TA106), that are used as a general background structure including for measuring, but which themselves cannot be measured.
The discussed points, together with differences of opinion such as those offered by Beamish and Boyd, suggest that physicists use the ‘speed of light’ concept in two different meanings. The stabilizing (anchor point) function of such working-postulates (working-beliefs) ought to be distinguished in principle from results of measurements, as they can be obtained in the case of the ‘speed of light’. In other words, c is :
(a) a measurable physical quantity with some variability; it has often been measured by physicists over the centuries (C17<5>),
(b) a postulated MIR-‘absolute’ anchor-point or theory-stabilizer, as the (standardized) average speed of light.
Einstein did not make this distinction; for instance in §1 he wrote that the magnitude of V (or c) is posited as a universal constant ‘der Erfahrung gemäß’, i.e., according to experience, which is not correct (see C19); there are no empirical absolutes. He could have added ‘approximately ’ or ‘more or less’; without that, his statement conflates (a) with (b), by neglecting (a). A probable reason for the conflation was that Einstein for one thing did not have the recent findings of type (a), mentioned in C19, at his disposal. But probably more important was that he wanted an MIR-based absolute anchor-point (b) for his theory, which cannot be done from (a). It appears that in this way, the absolute speed (b) has come to be seen as ‘the’ speed of light (C17, C18); the assertion of independence from subjects is apparently a default-consequence resulting from Einstein's elimination of the subject(s) (see ff above).
Does the (relatively small) variability of c interfere with the stabilizing function; for instance does it affect E = mc2 ? My present guess is that it does not : because the standardized absolute concept (b) is used, rather than the measurable quantity (a). (Are the obtained results in agreement with those expected when using the average of ‘c’ ?)
Although (a) and (b) are different functions, both refer to the same physical phenomenon, the speed of light. Thus one has to ask what the relation is between them. As a first approximation, one might compare them to two types of function of (b) the normative function of a politico-administrative law versus (a) the ‘observed’ behaviour of citizens with regard to the legislated norms.
In a tentative operational formulation :
(a) is an enquiry about properties of a specific conceptual working-tool (speed of propagation of light) while used, by people (‘observers’), via measurement and/or other feedback, resulting in a ‘finding’ within experience;
(b) is a normative decree or guideline for the standardization and stabilization of thinking; it is derived from (a), but posited, and qua decree or posited stabilizer it is not a result of measurement. It is instead considered to be a mind-independent absolutely valid ‘given’ as per dogma (cf.C19<1>). Using it as such requires an ontological leap of faith, like all MIR-beliefs. By using it the subject(s) exclude themselves from the imagined absolute reality. The absoluteness (stability) depends on absence of doubt.
Difficulties in using (b) as absolute stabilizer may therefore arise when it is acknowledged that it is humanly constructed and posited rather than a (‘given external’) MIR-absolute, because doubt is no longer excluded; this kind of difficulty can occur with all anchor-structures. However, conversion to working (as-if) MIR is possible, which re-introduces its ad-hoc-ness and temporary quality, and in effect reduces (b) to (a). But even as-if-MIR can provide a working-stability, but it remains in principle ad-hoc and temporary.
This last aspect is a probable reason for defending the MIR-absoluteness of ‘c’ (as in C17 and C18). But in this connection one has to ask : what can ‘absolute speed of light’ (b) possibly mean, other than a proposal for an absolute standard, if it is not relative to somebody ? One would not be able measure it, and therefore it cannot be a type (a) working tool. - By the way, the attempt by Richard Dawkins to convert the (b)-type question of the existence of God into an (a)-type study, and into an MIR-objective study to boot, illustrates a similar difficulty, or perhaps one should rather say misunderstanding (cf. TA106  to ).
In the introduction, Einstein wrote that the concept of ‘absolute rest’ does not correspond to any (observable) phenomena; by implication he seems to have assumed that the ‘absolute speed of light’ does correspond to phenomena. This is only approximately correct for observations (a); that fact interferes with assumption (b) in principle, but not in practice, since the decree or guideline (b) has ‘autonomy’ assigned to it, so to speak.
The change in anchor point seems to be a crucial factor for the advances made possible by relativity theory : the new anchor was less obstructive than the old one, because its guidelines were closer to what could be measured. In general, anchor-structures can be useful as working- and exploratory tools so long as their directives for thinking do not grossly contradict what is found in type (a) investigations (as for instance in Bible-based creationism (b) versus findings in studies of evolution (a)). This factor is active in addition to the mentioned more general problem  resulting from the insight that the alleged MIR-absolute norms are really human postulates.
Subject-exclusion versus subject-inclusion
One also has to ask whether it causes any difficulties, for the effectiveness of the theory, to accept that speeds are always measured by people, and that therefore speeds are subject-inclusive, per operational definition, and that ‘absolutes’ as well are human tools : of normative type. The answer is probably ‘no’. But the subject’s inclusion implies among other things that the speed is not independent of the movement of the observer, even though it is independent of the speed of the emitting source.
This result might affect the overall interpretation of the theory, because the observer is now at its center; in other words, relativity changes from Einstein’s subject-exclusive theory to a subject-inclusive, and actually (individual-and-collective) subject-centered, though not solipsistic, theory; that is a characteristic of all constructivist views. Characteristics of light are of great interest, because the human world-constructions are of predominantly visual-gestalt type.
A related question is whether the effectiveness of the theory is impaired in case it is accepted that all concepts are created within (individual and/or collective) ongoing awareness or consciousness or experience. So far I can see no reason why it should be, since the central concept, c, is of the normative type (b).
But as Raman points out (C17<10>), all theories may eventually be replaced by better ones.
And as I mentioned above, the presented tentative proposals are meant to stimulate discussion. I would also like to know more about Boyd’s ideas about the ‘relations to consciousness’ (C19<13>); perhaps in form of a Target Article ?
The following is a copy, of the introduction only, to A Einstein’s paper on special relativity, 1905, in German, and in an English translation. The complete German paper, and the complete English translation plus some explanatory notes, are available from the mentioned Internet-sources.
[ From Annalen der Physik 17, p. 891 f., 1905. Also available from the following Internet source :
3. Zur Elektrodynamik bewegter Körper;
von A. Einstein.
Daß die Elektrodynamik Maxwells — wie dieselbe gegenwärtig aufgefaßt zu werden pflegt — in ihrer Anwendung auf bewegte Körper zu Asymmetrien führt, welche den Phänomenen nicht anzuhaften scheinen, ist bekannt. Man denke z. B. an die elektrodynamiscbe Wechselwirkung zwischen einem Magneten und einem Leiter. Das beobachtbare Phänomen hängt hier nur ab von der Relativbewegung von Leiter und Magnet, während nach der üblichen Auffassung die beiden Fälle, daß der eine oder der andere dieser Körper der bewegte sei, streng voneinander zu trennen sind. Bewegt sicb nämlich der Magnet und ruht der Leiter, so entsteht in der Umgebung des Magneten ein elektriscbes Feld von gewissem Energiewerte, welches an den Orten, wo sich Teile des Leiters befinden, einen Strom erzeugt. Ruht aber der Magnet und bewegt sich der Leiter, so entsteht in der Umgebung des Magneten kein elektrisches Feld, dagegen im Leiter eine elektromotorische Kraft, welcher an sich keine Energie entspricht, die aber — Gleichheit der Relativbewegung bei den beiden ins Auge gefaßten Fällen vorausgesetzt — zu elektrischen Strömen von derselben Größe und demselben Verlaufe Veranlassung gibt, wie im ersten Falle die elektrischen Kräfte.
Beispiele ähnlicher Art, sowie die mißlungenen Versuche, eine Bewegung der Erde relativ zum „Lichtmedium" zu konstatieren, führen zu der Vermutung, daß dem Begriffe der absoluten Ruhe nicht nur in der Mechanik, sondern auch in der Elektrodynamik keine Eigenschaften der Erscheinungen entsprecben, sondern daß vielmehr für alle Koordinatensysteme, für welche die mechanischen Gleichungen gelten, auch die gleichen elektrodynamischen und optischen Gesetze gelten, wie dies für die Größen erster Ordnung bereits erwiesen ist. Wir wollen diese Vermutung (deren Inhalt im folgenden „Prinzip der Relativität" genannt werden wird) zur Voraussetzung erheben und außerdem die mit ihm nur scheinbar unverträgliche Voraussetzung einführen, daß sich das Licht im leeren Raume stets mit einer bestimmten, vom Bewegungszustande des emittierenden Körpers unabhängigen Geschwindigkeit V fortpflanze. Diese beiden Voraussetzungen genügen, um zu einer einfachen und widerspruchsfreien Elektrodynamik bewegter Körper zu gelangen unter Zugrundelegung der Maxwellschen Theorie fur ruhende Körper. Die Einführung eines „Lichtäthers" wird sich insofern als überflüssig erweisen, als nach der zu entwickelnden Auffassung weder ein mit besonderen Eigenschaften ausgestatteter „absolut ruhender Raum" eingeführt, noch einem Punkte des leeren Raumes, in welchem elektromagnetische Prozesse stattfinden, ein Geschwindigkeitsvektor zugeordnet wird.
Die zu entwickelnde Theorie stützt sich — wie jede andere Elektrodynamik — auf die Kinematik des starren Körpers, da die Aussagen einer jeden Theorie Beziehungen zwischen starren Körpern (Koordinatensystemen), Uhren und elektromagnetischen Prozessen betreffen. Die nicht genügende Berücksichtigung dieses Umstandes ist die Wurzel der Schwierigkeiten, mit denen die Elektrodynamik bewegter Körper gegenwärtig zu kämpfen hat.
[ The following English translation is from : https://www.fourmilab.ch/etexts/einstein/specrel/www/ ]
ON THE ELECTRODYNAMICS OF MOVING BODIES
June 30, 1905
It is known that Maxwell's electrodynamics--as usually understood at the present time--when applied to moving bodies, leads to asymmetries which do not appear to be inherent in the phenomena. Take, for example, the reciprocal electrodynamic action of a magnet and a conductor. The observable phenomenon here depends only on the relative motion of the conductor and the magnet, whereas the customary view draws a sharp distinction between the two cases in which either the one or the other of these bodies is in motion. For if the magnet is in motion and the conductor at rest, there arises in the neighbourhood of the magnet an electric field with a certain definite energy, producing a current at the places where parts of the conductor are situated. But if the magnet is stationary and the conductor in motion, no electric field arises in the neighbourhood of the magnet. In the conductor, however, we find an electromotive force, to which in itself there is no corresponding energy, but which gives rise--assuming equality of relative motion in the two cases discussed--to electric currents of the same path and intensity as those produced by the electric forces in the former case.
Examples of this sort, together with the unsuccessful attempts to discover any motion of the earth relatively to the “light medium,” suggest that the phenomena of electrodynamics as well as of mechanics possess no properties corresponding to the idea of absolute rest. They suggest rather that, as has already been shown to the first order of small quantities, the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good.1 We will raise this conjecture (the purport of which will hereafter be called the “Principle of Relativity'') to the status of a postulate, and also introduce another postulate, which is only apparently irreconcilable with the former, namely, that light is always propagated in empty space with a definite velocity c which is independent of the state of motion of the emitting body. These two postulates suffice for the attainment of a simple and consistent theory of the electrodynamics of moving bodies based on Maxwell's theory for stationary bodies. The introduction of a “luminiferous ether'' will prove to be superfluous inasmuch as the view here to be developed will not require an “absolutely stationary space'' provided with special properties, nor assign a velocity-vector to a point of the empty space in which electromagnetic processes take place.
The theory to be developed is based--like all electrodynamics--on the kinematics of the rigid body, since the assertions of any such theory have to do with the relationships between rigid bodies (systems of co-ordinates), clocks, and electromagnetic processes. Insufficient consideration of this circumstance lies at the root of the difficulties which the electrodynamics of moving bodies at present encounters.
Herbert FJ Müller
e-mail <herbert.muller (at) mcgill.ca>