KARL JASPERS FORUM
TA106 (Müller)
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
[1]
INTRODUCTION
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.
[2]
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.
[3]
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.
[4]
BACKGROUND
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.
[5]
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.
[6]
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’) :
[7]
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 ...’ ]
[8]
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.
[9]
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.
[10]
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.)
[11]
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.
[12]
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.
[13]
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.
[14]
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.
[15]
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 [6]ff above).
[16]
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’
?)
[17]
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.
[18]
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.
[19]
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.
[20]
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 [3] to [6]).
[21]
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.
[22]
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 [19] resulting from the insight
that the alleged MIR-absolute norms are really human postulates.
[23]
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.
[24]
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.
[25]
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 ?
------------------------------------------------------
APPENDIX
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
by A.
Einstein
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>