Transverse Gravitational Redshift: a previously-unmodeled relativistic gravitational phenomenon having a subtle measurable effect on time metrology and spacecraft telemetry Alexander F. Mayer • [email protected]
ABSTRACT The following formula rests on the Einstein equivalence principle; it is derived simply, in a few logical steps, guided exclusively by first principles. It predicts the existence of a symmetric redshift zδ between two points at identical coordinate radius r separated by a constant distance [δ ≪ r] in a static, spherically-symmetric gravitational field; the field absorbs a minute portion of a photon’s energy when the photon is transmitted transverse to the local gravitational gradient. Circa Q4 2015, textbook general relativity (GR), overlooks this clearly-implied relativistic phenomenon (see Fig. 1). The accuracy of the following formula is dependent on the accuracy of the approximation sin(δ/r) ≈ δ/r, which imposes the ‘small-distance’ restriction [δ ≪ r] on measurement.
2 g 2 δ µ δ µ zδ ≈ 3 2 = 2 [δ << r] • µ ≡ GM • g = 2 r c rc r This reveals an oversight in canonical GR: time is endowed with geometric properties that were not incorporated in the original presentation of the theory. When this omission is remediated, a symmetric time dilation is modeled between points at the same Newtonian potential. The following formula, which is derived from pure geometry arising from the principles of relativity, calculates an accurate value for the relativistic “transverse gravitational redshift” (TGR) effect between any two points in the weak field, which field assumes an idealized static point source. The symbol b is a conventional impact parameter. E(ϕ|m) represents an elliptic integral of the second kind; additional details are contained in this report. When evaluated between antipodes (i.e., b = 0), zt = 0.
⎡ ϕ2 ⎤ ⎧ ⎫ RS ⎛ ϕ ⎞ ⎤ ⎪ ⎡ π π ⎤ ⎪ 2µ zt = sec ⎢2 E ⎜ 2⎟ ⎥ ⎥ −1 ⎨ [b > 0] & − ≤ ϕ ≤ ⎬ • RS ≡ 2 ⎢ b ⎝ 2 ⎠ ⎥ ⎣⎢ 2 2 ⎦⎥ c ⎣ ⎦ϕ1 ⎦ ⎩⎪ ⎭⎪ Plugging in values for the realistic test case of a 1-km horizontal separation distance on the geoid (p. 21), these two radically different formulas agree to one part per billion (10−9):
Approximation: zδ(1 km) = 1.71503723208E−17 ……………… zδ(10 km) = 1.715037232E−15 Authoritative: zt(1 km) = 1.71503723031E−17 ……………… zt(10 km) = 1.715037056E−15 This feature of the mathematical physics provides a theoretical ‘proof’ that the predicted phenomenon is real. A quantitative survey of the literature reveals that it is routinely observed astrophysically; these observations were either unexplained or misidentified. Numerous university physics laboratories have the necessary off-the-shelf equipment and technical expertise required to run various possible experiments to empirically verify the predicted phenomenon conclusively at nominal cost. Unexplained anomalies in GPS can be attributed to the unmodeled TGR effect, which may be partially absorbed in estimated user equivalent range errors (UERE).
© 2015 A. F. Mayer 1 ver. 15.11.05.Z17 Part I: Theory
“We are not to tell Nature what she’s gotta be.” – Richard P. Feynman (1979)
Introduction Reliable first principles in physics, (e.g., the Einstein equivalence principle), are proven direct predictors of empirical phenomena, (e.g., the Einstein redshift). This report presents the prediction of a testable, previously unrecognized relativistic gravitational phenomenon implied by the Einstein equivalence principle. Two independent predictive formulas for the same phenomenon are presented: an approximation valid for ≲100 km horizontal distances on Earth, which rests on the Einstein equivalence principle, and a general formula applicable between any two points in the weak external field, which is based on the revolutionary concept of relativistic temporal geometry, which itself arises from first principles. The respective mathematical forms of the two equations are radically different and it is impossible to derive one equation from the other, yet they agree quantitatively to one part per billion in a test case that can be verified by dozens of university laboratories. This feature of the mathematical physics, alone, provides strong assurance that the predicted phenomenon is real. A quantitative survey of the professional literature reveals that it has been previously observed numerous times and in numerous circumstances dating back to the early 1900s when the center-to-limb variation of the solar wavelength was first reported.1 However, since the Einstein field equations and their practical physical interpretation as expressed by the parametrized post-Newtonian (PPN) formalism have been assumed to be an accurate gravitational model, and they failed to predict such a phenomenon, anomalous measurements that could not be explained within the context of conventional relativity have been typically attributed and quantitatively modeled by some ad hoc phenomenon (e.g., a ‘gravitational anomaly’ or ‘atmospheric effect’) that could be invoked without challenging long-accepted and widely-respected conventional thinking. Alternatively, the subset of such anomalous measurements reported in the literature were either summarily removed from the raw data as an inexplicable apparent nuisance, or they were simply ignored or ridiculed. A “gravitational equipotential surface” is a physical concept arising from pre-relativistic classical mechanics. According to the germane principles and mathematics, all points at rest on a spherical surface centered on an idealized gravitational point source are at the same energy potential. Moreover, according to Newton’s theory of universal gravitation, the gravitational field is conservative; for any closed path through the field, the net work (integrating force times distance) is zero. Similarly, modeling an ideal radar round trip of a photon in vacuum, there is no change in photon wavelength (i.e., photon energy) induced by propagation through gravitational fields. Originating with Newton, these two notions became axioms (i.e., propositions regarded to be self-evidently true) that were unchallenged with the advent of modern physics, which holds Newtonian physics to be a low-error practical approximation to more generally applicable relativistic mechanics.
1 Paul Marmet, “Redshift of Spectral lines in the Sun’s Chromosphere,” IEEE Tran. Plasma Sci. 17 (2), 238 (April 1989); < online > < online2 >.
© 2015 A. F. Mayer 2 ver. 15.11.05.Z17 The question arises as to whether these notions are in fact low-error approximations in the context of relativistic physics. Might a requisite but overlooked empirical relativistic effect exist that is subtle enough in the weak field to have escaped ready detection and distinction from various possible constituents of experimental error budgets? Even for experts in relativity theory, interpreting the cryptic mathematics of general relativity is notoriously difficult; a subtle error in the assumptions underlying such interpretation or an oversight of the relevant principles will result in an erroneous model. A conviction in the infallibility of the conventional textbook treatment of general relativity produced by a century of academic work in relativistic gravitational physics is judiciously subject to skepticism and reexamination; science is about challenging the status quo. In theoretical physics, simple qualitative models that rest on established first principles provide a “reality check” on the interpretation of quantitative models in the form of complex mathematical symbology. More importantly, such intelligible qualitative models serve to guide the derivation and evolution of quantitative mathematical models that accurately predict empirical phenomena. Such a quantitative predictive model must be empirically measurable with available technology, allowing the underlying model to be tested and either falsified or verified within evolving boundaries of experimental error. The Fig. 1 schematic depicts four ideal clocks (A – D) at rest in an idealized static, spherically-symmetric gravitational field that is isolated from all external influence and a fifth inertial clock (I ) free of gravitational influence at arbitrarily-large coordinate radius.
Scalar approximation† source of ‘tick’ pulses A clock at rest for the speed of light faster* relative to μ (over chords AB & AC r B * B:C relative A.tick arrival I dt # " & I rate per dtI v ! c%1+ 2 ( 0 r → ∞ $ c ' slo θ we − r* C Φ → 0 " AC < " AB < 0
) vAC < vAB (per the clock-I inertial-observer increasing µ ! = " reference: v ≡ c) N I μ ≡ GM potential e r w (Φ < 0) t o n ia n ‘e q † u Accurate expression i p π requires a tensor feld. ot en tia l su The speed of light between clocks rface’ Ideal clocks A – D are at rest in A & C is less than between A & B, an idealized static, spherically- which has relativistic implications. D symmetric gravitational feld. Fig. 1
© 2015 A. F. Mayer 3 ver. 15.11.05.Z17 The Schwarzschild metric is conventionally applied external to the source mass, where dτ represents local proper time (e.g., the time recorded by clock A) and dt represents coordinate time recorded by an inertial clock, here represented by clock I :
−1 2 2 ⎛ RS ⎞ 2 2 ⎛ RS ⎞ 2 2 2 2 2 c dτ = 1− c dt − 1− dr − r dθ + sin θdφ (1) ⎝⎜ r ⎠⎟ ⎝⎜ r ⎠⎟ ( ) For a static location (dr = dθ = dϕ = 0), the metric reduces to Eq. (2), which models the empirically-verified phenomenon of gravitational time dilation. The relative rate of ideal clocks at rest in a gravitational field is related to the local gravitational potential, which is correlated to the coordinate radius r; clocks at lower potential (i.e., lower r) tick slower.
1 − 2 2 ⎛ RS ⎞ 2 dt ⎛ RS ⎞ 2µ dτ = ⎜1− ⎟ dt → = ⎜1− ⎟ • RS ≡ 2 (2) ⎝ r ⎠ dτ ⎝ r ⎠ c
According to this well-known predictive formula, ideal test clocks (A – D) all tick at the same reduced rate with respect to the ideal inertial reference clock I. This being the case, one might then jump to the conclusion that clocks A – D are all synchronous relative to one another. A simple example taken from special relativity suggests that such assumption of mutual synchronization of a set of ideal clocks, based on their individual synchronization with an ideal reference clock, is unwarranted and requires more careful consideration. In Fig. 2, each of the three ideal test clocks (A – C ) have the identical relative speed (|vα| = v) with respect to the ideal rest-frame reference clock. Accordingly, all three test clocks record local proper time at the same reduced rate with respect to clock I. However, since no two of the test clocks in are in the same frame of reference, it is clearly the case that no two of these clocks are synchronous with respect to one another, which is quantified by the non-zero Δv between them.
vA vB v v v v A A = B = C = B v dtI dtI dtI C ! = = C d! A d! B d! C
I Fig. 2 rest frame
Referring to Fig. 1, let the test clocks transmit the measured rate of local proper time by emitting a pulse of light per unit of local time (e.g., clocks emit 1 GHz pulses). From the point of view of an inertial observer referencing local clock I, the average speed of light integrated over the null geodesic AC is less than that over AB because the latter geodesic travels through a lower potential (i.e., space having higher average curvature). Ergo, in reference to clock I, the inertial observer records regular timing pulses sourced at clock A to arrive at clock C at a lower frequency than at clock B; within an arbitrary
© 2015 A. F. Mayer 4 ver. 15.11.05.Z17 interval of coordinate time Δt, more ‘clock ticks’ sourced at clock A arrive at clock B as compared to clock C. Because clocks B and C tick at the identical rate relative to clock I, it is also true that the local proper time interval between received clock-A timing pulses is less as measured at clock B than as measured at clock C. These unequivocal facts and the applicable symmetry imply a bilateral relativistic time dilation that is a function of the azimuthal angle (θ ) between ideal clocks at relative rest and at the same Newtonian gravitational potential. From the point of view of each of two such clocks, the remote ideal clock ticks at a lesser rate than the local clock. It is important to note that this relativistic time dilation effect is not a monotonically increasing function of the distance between the two clocks (i.e., the azimuthal angle θ between them). This is immediately evident from the symmetry between clocks A and D in Fig 1; considering the signal path, the magnitude of the gravitational blueshift to the center of mass is identically equal to the magnitude of the gravitational redshift from the center of mass to the other clock. Accordingly, antipodal ideal clocks (A, D) at the same coordinate radius in the Fig.1 schematic are synchronous with respect to one another. It is exclusively the component of a null geodesic that is transverse to the local gravitational gradient that produces the relativistic bilateral time dilation effect, “transverse gravitational redshift” (TGR). As the magnitude of this transverse signal-path component initially increases from zero as θ increases from zero and then returns to zero as θ increases to pi radians, the TGR effect between endpoints at the same coordinate radius is a function of the azimuthal angle between them, which function f (θ) is periodic over [0 ≤ θ ≤ π]: f (0) = f (π) = 0. After consideration of the forgoing argument, it is necessary to concede that a formal mathematical system that contradicts this prediction (i.e., historical conventional GR) must incorporate some error in expressing the constituent fundamental principles of the general theory of relativity. Moreover, prior empirical measurements and tests of GR that certainly measured the phenomenon, but failed to recognize it, employed procedures to obscure the anomaly so that reported results would be consistent with canonical theory.
Background It will be shown that the canonical model of relativistic time dating back about a century incorporates a very subtle modeling error (i.e., omission) for measurable phenomena. The prevailing conception of universal spacetime as a “3+1” manifold proves to be an incorrect general application of a geometric model that is valid only for a localized reference frame. The conception of spacetime as having one geometric time dimension is similarly false to the seemingly rational but primitive misconception of one geometric altitude dimension, parallel everywhere in three-dimensional space over a naïvely modeled ‘flat’ Earth. Just as we experience the ‘altitude dimension’ (i.e., local vertical) of each distinct point on a sphere to be geometrically distinct, the time dimension of each quantitatively-distinct reference frame in relativistic physics must be similarly visualized, which is inherently in accord with the fundamental principles of relativity. By definition, ideal clocks that accurately record local time in such distinct reference frames are not synchronous due to relativistic effects. A key new idea presented here is the physical interpretation of this measurable phenomenon: although a differential clock rate is the familiar observable and it is clear that relativistic time is an empirical reality, such ideal
© 2015 A. F. Mayer 5 ver. 15.11.05.Z17 clocks having a relativistic relationship are not measuring local time at different rates per se. Rather, the more fundamental physical reality is that these clocks are measuring somewhat different orientations of time in a physically abstract four-dimensional manifold. “Physically abstract” means that no measurable quantity such as space or time can be attributed to any of the four arbitrarily-oriented manifold dimensions. There is no universal ‘direction’ (i.e., manifold dimension) of time; time is a strictly-local geometric distinction in “spacetime.” This seemingly abstract physical concept may not be intuitive upon initial consideration, but subsequent discussion will make it seem obvious. Similarly, the fact that the orientation of the local gravity vector is not globally parallel, which seems obvious today, is not naturally intuitive; for example, it remained obscure in China until the spherical Earth was introduced by European missionaries in the seventeenth century.2 In 1905 Einstein abandoned the false Newtonian concept of absolute universal time; the algebra expressed temporal relativity as a difference in the measurable rate of clocks. Some months prior to his untimely death in January 1909, Hermann Minkowski put forward a more robust expression of Einstein’s special relativity in the context of geometry (i.e., a metric).3, 4 What was overlooked then, and over the ensuing century, is that the fundamental physical interpretation of Minkowski’s mathematics concerns the relative orientation (i.e., geometry) of time for distinct reference frames in the four- dimensional spacetime manifold. The concept of distinct observers measuring time in an arbitrary number of directions in a four-dimensional manifold was as unintuitive in the twentieth century as was the concept of altitude having different directions in space for ancient Western cultures prior to the first century of the Common Era. Although both ideas are actually simple and even empirically manifest, they are a radical departure from preceding ‘common sense’ thinking based on a naïve physical perspective. Accurate physical interpretation of the fundamental mathematics underlying relativity theory requires the respective time dimensions of distinct reference frames to be geometrically distinct. Minkowski’s mathematical formulation of Einstein’s revolutionary ideas concerning relativistic time implies that relativistic time involves relative geometry of geometrically-distinct time dimensions associated with distinct reference frames. Physically interpreted, the mathematics implies that these geometrically-distinct time dimensions are not collinear (i.e., parallel) in 4D spacetime. This idea of the progress of time having the similar property of orientation in a multi-dimensional manifold, as is true and familiar for arbitrary translation vectors in three-space, is highly non-intuitive because the common human experience of time is bidirectional; particularly in Western culture, we experience and model time as a linear phenomenon (i.e., a timeline), with time bifurcated into the past and the future by the elusive existence of the ‘present moment.’ The relativity of simultaneity informs us that this bifurcated ‘common sense’ linear model of time is a naïve perceptual illusion. A universally-linear model of time, which is practical for everyday human activity, is not generally valid in modern physics, which necessarily must deal with phenomena at vast and infinitesimal extreme scales of time and space far beyond the narrow boundaries of common human physical experience.
2 Carlo Rovelli, “Science Is Not About Certainty,” New Republic (11 July 2014); < online >. 3 H. Minkowski, “Das Relativitätsprinzip,” Annalen der Physik 352 (15), 927 (1907/1915); < online >. 4 H. Minkowski, “Raum und Zeit,” Jahresber. Deutsch. Math.-Verein, 75 (1909); < online >.
© 2015 A. F. Mayer 6 ver. 15.11.05.Z17 Physics Let us first review the known phenomenon of Einstein redshift: Consider ideal clocks at rest in a gravitational field (Fig. 3). Due to gravitational relativistic effects, the measured rate of clock A as compared to an ideal inertial clock (I ) at radius r → ∞ from the isolated gravitational point source is correlated to the energy differential between the two clocks, which is quantified by the characteristic gravitational escape velocity (Eq. 3) at the location of clock A. The magnitude of the Einstein redshift (zE), which is correlated to the measurable differential clock rate, is accurately expressed in terms of this escape velocity (Eq. 4). Alternatively, a close approximation to the Einstein redshift (Eq. 5) in a weak (i.e., dg/dh → 0) gravitational field over short vertical distances (Δh ≲1 km) may be derived using energy conservation or the Einstein equivalence principle. Eq. (4) and Eq. (5) have distinct mathematical forms and it is impossible to derive one formula from the other.
I r → ∞ g → 0 inertial observer
dtI = f (vesc ) dtA $dg ' ! "h # 0 %&dh ()
A g h
gravity (v ) Fig. 3 esc
2µ v = • µ ≡ GM (3) esc r
dt 1 1 1 2µ z = I −1 = −1 = −1 = −1 • R ≡ E 2 S 2 dtA 2µ R c (4) ⎛ vesc ⎞ S 1− 1− 2 1− ⎝⎜ c ⎠⎟ rc r
g ⋅ Δh z ≈ (5) E c2 Using a purely mathematical process, the Eq. (4) prediction is typically derived from the Schwarzschild solution to the Einstein field equations. In contrast, the Eq. (5) prediction is easily derived directly from the Einstein equivalence principle (EEP), as elegantly
© 2015 A. F. Mayer 7 ver. 15.11.05.Z17 described in the Feynman Lectures on Physics:5 For a vertical separation (Δh) of two ideal clocks inside a rocket accelerating at rate g in inertial space (Fig. 4), one considers the nominal inertial-frame photon propagation time between the two clocks (Δh/c), which value ignores the second-order component induced by a small acceleration. In this time the rocket has increased its velocity in the inertial frame by the following magnitude.
Δh Δv = g ⋅ Δt ≈ g ⋅ • g ∼ 10 m s−2 (6) c From the point of view of an unaccelerated free-falling inertial observer external to the rocket, photons emitted from a lower clock in the rocket’s tail ‘chase’ a higher clock in the rocket’s nose and are therefore redshifted upon arrival. The Eq. (7) approximation yields a measurably-accurate value of this Doppler redshift for sufficiently small Δv.
Δv zD ≈ [Δv << c] (7) c
Substituting the Eq. (6) expression for Δv into Eq. (7) yields the familiar Eq. (5) formula.
A subtle property of this inertial-frame equivalent to the clocks shown in Fig. 3 is the speed of the rocket (|v|) relative to an inertial observer (I ). I B g ≡ 0 Δh inertial observer v dt I = f ( v ) d! A A g
An equivalence that includes relationship I ⇒ A
requires |v| = vesc, where vesc is defined in Fig. 3. Fig. 4
Accelerated observers inside the rocket experience the clocks to be at rest within their reference frame, yet they are required to measure the same frequency shift between the clocks as is ‘measured’ by the inertial observer, based on the comoving motion of the clocks in the inertial frame over the photon propagation time. Accordingly, accelerated observers inside the rocket must attribute the observed photon frequency shift between clocks at relative rest exclusively to a relativistic time-dilation effect between the clocks. This shift is readily observed to be a function of the measured local acceleration (Eq. 5) when g is varied. Per EEP, Eq. (5) is equivalently applicable for gravity, yet a notable
5 Richard Feynman, Robert B. Leighton & Matthew Sands, The Feynman Lectures on Physics, Volume II (Addison-Wesley, Reading MA, 1964), §42-6, p. 42-9; < online >.
© 2015 A. F. Mayer 8 ver. 15.11.05.Z17 difference between an inertially-accelerated frame (e.g., a rocket in gravity-free space) and a real gravitational field is the absence of gravitational tidal forces in the rocket. In the context of relativity, there are two important measurable properties associated with a particular location in a gravitational field: the local gravitational acceleration and the energy relationship (i.e., Newtonian potential) between this location and a distant inertial observer in gravity-free space. In accurately modeling the inertial equivalent to such a location, including time dilation, both of these two properties must be considered. Accordingly, the accelerating rocket cannot have an arbitrary speed relative to a free- falling inertial observer; it must be considered exclusively at the ideal moment that its speed relative to this inertial observer is equal to the local gravitational escape velocity (vesc) at the location of the gravitationally-accelerated reference frame being modeled (Fig. 4). In this case, an accelerated ideal clock (A) within the rocket will tick measurably slower than an inertial ideal reference clock (I ), having the identical temporal relativistic relationship to that between the modeled gravitationally-accelerated ideal clock at rest with respect to a distant inertial reference clock (Fig. 3). At any other relative speed between an inertial observer and the accelerating rocket (Fig. 4), equivalence does not hold with respect to this fundamental relationship (relativistic time dilation), arising from a difference in gravitational potential energy (Fig. 3). This subtle detail of equivalence is not relevant to modeling the Einstein redshift in an inertially-accelerated frame, so it was easily overlooked in the past. However, it is critically relevant when lateral gravitational tidal force associated with real astrophysical gravitational fields is taken into consideration in the equivalence model. In such fields, gravitational acceleration is not parallel between points separated by any appreciable horizontal distance (Fig. 5). The model geoid in this schematic is idealized in that we consider |g| to be equal everywhere on the surface and the source body has no angular momentum, so that Sagnac and any relative velocity effects are eliminated. The small angle approximation (sin θ ≈ θ) must hold for the identical angle of separation between the two clocks in the Fig. 5 and Fig. 6. schematics (i.e., θδ ≪ 1). This essential restriction for the vector equation [dg/dθ · θδ → 0] in Fig. 5 is similar to the essential restriction for the scalar equation [dg/dh · Δh → 0] in Fig. 3. Accordingly, the distinct acceleration vectors (gA , gB), though not parallel, are very nearly so (i.e., the vector difference in acceleration between the two compared clocks is very small, but not zero). Clocks A and B are in different frames of reference due to the subtle vector distinction Δg ≠ 0.
A B g g A δ ≪ r B (v ) dg al geoid esc # 0& ide % !!" " ( [ω = 0] $d! ' r (radius) " ! = !1 " r Fig. 5
© 2015 A. F. Mayer 9 ver. 15.11.05.Z17 I g ≡ 0 vA vB inertial observer A B
g g
rockets accelerating in gravity-free space dv/dt = g |vA| = |vB| = vesc
vesc and θδ reference the empirical values on the Fig. 5 geoid.
θδ Fig. 6
The two ideal clocks separated by the arc δ in Fig. 5 comprise a system. We now consider the inertially-accelerated equivalent of this system. Accordingly, there are two distinct accelerating rockets on divergent trajectories (Fig. 6), having the identical small angle between these trajectories as angle θδ in Fig. 5. Clearly, the divergence of these trajectories implies that respective observers in A and B make local measurements in distinct inertially-accelerated frames of reference. The relativistic relationships [I ⇒ A] and [I ⇒ B] are identical; the clocks in both accelerating rockets tick measurably slower relative to an inertial reference clock (I ) in exactly the same proportion because the only relevant factor is the identical speed of the rockets (vesc) relative to this clock, where this speed is the characteristic escape velocity of the model geoid in Fig. 5. The fact that the rockets are on different trajectories has no part to play in these two specific relationships. Symmetry considerations require that an inertial observer will measure both of the accelerated clocks A and B (moving at the identical speed vesc relative to clock I ) to each tick at the same rate relative to this inertial reference clock. However, this symmetry is broken in considering the relationship between A and B themselves, which clearly represent distinct frames of reference. The divergent velocity vectors (vA , vB) imply an energy differential between frames A and B quantified by the change in velocity between them, which is a vector quantity with a non-zero magnitude (Δv). Due to the restriction (θδ ≪ 1), the component of Δv (similarly Δg) that is collinear with the acceleration vectors
© 2015 A. F. Mayer 10 ver. 15.11.05.Z17 is vanishingly small. This energy differential represents an inherent symmetric energy cost associated with the propagation of an electromagnetic signal between the two reference frames that is transverse to the direction of acceleration. This symmetric energy cost implies a readily-quantifiable symmetric relativistic relationship between the respective ideal clocks in frames A and B: from the point of view of clock A, clock B appears to tick slower, and from the point of view of clock B, clock A appears to tick slower, both according to Eq. (8). dt dt 1 A = B = (8) d d 2 τ B τ A ⎛ Δv⎞ 1− ⎝⎜ c ⎠⎟
The Einstein equivalence principle implies that what is true for the energy relationship between the two rockets (i.e., inertially-accelerated clocks) in Fig. 6 is identically true for the two gravitationally-accelerated clocks in the Fig. 5 schematic. According to this principle, the 17th-century Newtonian concept of a “gravitational equipotential surface” must be abandoned. This assertion, which is justified in what follows, corroborates the same qualitative conclusion drawn in §Introduction, which references Fig. 1. Per the following discussion, it immediately follows from Eq. (8) that the predicted redshift (zδ) for a separation distance δ restricted to the condition [δ ≪ r] is:
2 g 2 δ µ δ µ (9) zδ ≈ 3 2 = 2 [δ << r] • g = 2 r c rc r
This restricted approximation formula is of a similar nature to Eq. (5), which yields an accurate approximation for the Einstein redshift with immeasurable error for sufficiently small vertical displacements (Δh) in the weak field. To be clear, Eq. (9) is derived directly from Eq. (8) using the following applicable approximations of very high accuracy under the stated respective restrictions. The first approximation (LHS of Eq. 10) is well known and arises from binomial expansion of relativistic gamma. The validity of the second approximation is dependent on the accuracy of the approximation sin(δ/r) ≈ δ/r.
1 Δv2 z = −1 ≈ Δv ≪ c 2 2 [ ] δ Δv 2c Δv ≈ vesc [δ ≪ r] (10) 1− r c2
It is natural to initially reject or even ridicule Eq. (9) based on preconceived notions from pedagogical learning and from some prior-reported empirical evidence, which together provide a false sense of certainty. Especially when an anomaly is quite small, expectancy theory suggests that observers will overlook such an anomaly and report measurements that are consistent with ‘correct’ measurement according to prevailing theory, which is universally assumed to be consistent with empirical reality. Evaluated over a 1-km separation distance on the surface of the Earth, Eq. (9) implies a symmetric redshift −17 measurement zδ ~ 10 as compared to a zero value consistent with conventional theory.
© 2015 A. F. Mayer 11 ver. 15.11.05.Z17 “That cannot possibly be right” or “everybody knows that Newton’s 17th-century idea of a gravitational equipotential surface is consistent with relativity” do not hold water in the context of the new idea of relativistic temporal geometry: In short, the reason that there is indeed a minute, non-zero energy cost associated with translation between the two points (A↔B) in Fig. 5 is that the ‘direction of time’ in spacetime is not identical for these two distinct frames of reference. This geometric distinction between the respective time coordinates, which is readily quantifiable in direct accord with first principles, implies the relativistic relationship. The concept of relativistic temporal geometry and its associated empirical phenomenon are not reflected in conventional general relativity, nor in its embodiment in the current PPN formalism. However, they are clearly and unequivocally reflected in the conceptually-simple Fig. 1 and the comparison of the Fig. 5 and Fig. 6 schematics when viewed in the context of the Einstein equivalence principle. The full development of relativistic temporal geometry, which constitutes an amendment to general relativity, is beyond the scope of this introductory report and its intended broad technical audience, inclusive of those who are inexpert in the mathematics of GR. However, the following predictive general equation (Eq. 11) arises from this amendment to that widely accepted theory. Derived from pure geometry motivated by first principles (see addendum to this report), it may be used to evaluate the magnitude of this previously-unrecognized relativistic phenomenon (TGR) that inherently exists between any two points in the weak field between which there exists a non-zero transverse (horizontal) gravitational tidal force. An idealized point-source mass producing a static, spherically-symmetric gravitational field is assumed. This ‘Schwarzschild simplification’ closely approximates the field of typical astrophysical bodies such as the Sun or the Earth, so the formula is accurate for any major solar system body. This formula predicts energy loss for an electromagnetic signal (i.e., a redshift, zt) incurred due to translation transverse to the local gravitational gradient, which energy loss is not now predicted by conventional general relativity. A corresponding symmetric difference in the measured frequency of ideal clocks exists. At first glance, Eq. (11) may seem cryptic; fundamentally, what this geometric formula calculates is the relativistic time dilation effect caused by the divergence of distinct proper time coordinates between two points in a gravitational field (i.e., two distinct frames of reference) due exclusively to lateral displacement in the field and excluding vertical displacement (i.e., Einstein redshift) and relative velocity (i.e., special relativity):
⎡ ϕ2 ⎤ ⎧ ⎫ RS ⎛ ϕ ⎞ ⎤ ⎪ ⎡ π π ⎤ ⎪ zt = sec ⎢2 E ⎜ 2⎟ ⎥ ⎥ −1 ⎨ [b > 0] & − ≤ ϕ ≤ ⎬ (11) ⎢ b ⎝ 2 ⎠ ⎥ ⎣⎢ 2 2 ⎦⎥ ⎣ ⎦ϕ1 ⎦ ⎩⎪ ⎭⎪
The function sec[u] is the reciprocal of the cosine. RS is the Schwarzschild radius of the source mass and b is a conventional “impact parameter,” or the distance of closest approach of the signal path to the gravitational point source. As shown in the Fig. 7 schematic, this distance may be virtual (i.e., the actual signal path between the points of emission and reception for which the value of zt is evaluated may not extend to the point at which this distance is measured). The term in parentheses prefaced by and inclusive of the symbol E represents an elliptic integral of the second kind. The physical meaning
© 2015 A. F. Mayer 12 ver. 15.11.05.Z17 of the angular term (φ) in Eq. (11) is illustrated in the Fig. 7 schematic. The parameter φ1 typically corresponds to the location of the signal source, while the similar parameter φ2 typically corresponds to the location of the receiver, but this convention is arbitrary, having no effect on the quantitative evaluation of Eq. (11). Note that Fig. 7 does not use this convention. Employing the standard convention, for a signal source that exists beyond the point of closest approach to the the gravitational source at which b is evaluated and φ1 is zero, the value of φ1 is negative. For a distant signal source that is is in opposition to and nearly occulted by an intervening astrophysical mass, for example interplanetary spacecraft telemetry in opposition to the Moon, limit values are φ1 → −π/2 and φ2 → π/2, being the maximum possible difference between these two parameters. The argument of the secant function in Eq. (11) is the result of the following integral:
R ϕ 2 u = S cosϕ dϕ (12) b ∫ϕ1
Accordingly, the single right bracket in Eq. (11) that expresses limits (φ1, φ2) means that the elliptic integral term is evaluated between φ1 and φ2 per Eq. (13).
ϕ2 ⎛ ϕ ⎞ ⎤ ⎛ ϕ2 ⎞ ⎛ ϕ1 ⎞ E 2 = E 2 − E 2 (13) ⎝⎜ 2 ⎠⎟ ⎥ ⎝⎜ 2 ⎠⎟ ⎝⎜ 2 ⎠⎟ ⎦ϕ1
zenith GPS SV
ground station a horizon ψ R a ≈ 26,560 km φ = ψ b 1 R ≈ 6,371 km φ2 φ φ = cos-1 b b = R cosψ 1 2 ( a ) Fig. 7
GPS SV: “GPS Space Vehicle” (i.e., “satellite”) zenith: located directly overhead (ψ = 90°) Note: Transit (the point of highest elevation angle ψ) is generally below zenith.
© 2015 A. F. Mayer 13 ver. 15.11.05.Z17 It should be clear that this predicted effect (Eq. 11) contributes to a total effect, which many include the influence of conventional gravitational time dilation due to relative vertical displacement or actual motion of the source relative to the point of reception. This new prediction corresponds to a radial pseudo-velocity (czt); although the frames may be at relative rest, they behave as if they were slowly moving away from each other. The respective time-dilation effects of the two velocities (real and pseudo), as well as any effect induced by difference in gravitational potential, are independently calculated and then summed to arrive at a total effect. Measured empirically, but not modeled, the TGR effect gives the illusion of recessional motion. However, it can be differentiated from such motion due to the correlated first-order time dilation: For radial motion, Doppler shift is of first order (v/c) and time dilation is of second order (relativistic γ); for TGR, both correlated relativistic effects are of first order (zt). The predicted effects of TGR have apparently been previously observed astrophysically dating back about a century and in various more-recent radio science experiments, although they were never recognized as an anomaly requiring an amendment to conventional GR and the PPN formalism. The argument of the sec[u] function in Eq. (11) represents the effective angle of divergence in spacetime between two distinct time coordinates, which respectively correspond to the two points in the field between which zt is being evaluated. The secant function should be recognized as the inverse dot product of normalized time-coordinate vectors. The nature of this geometric function is physically intuitive in the context of evaluating a relativistic time dilation between two distinct reference frames having strictly-local time coordinates (i.e., distinct linear time axes) that have different orientations in spacetime. The secant function evaluates the projection of the linear time coordinate of one reference frame (parallel transported) onto the geometrically distinct linear time coordinate of the other reference frame. Although this concept has not heretofore been incorporated in the pedagogy of relativity theory, the correct physical interpretation of relativity concerns the relative geometry of distinct local time coordinates; the measured relative rate of ideal clocks is a secondary effect produced by this more-fundamental physical reality. This is the only rational mathematical model of the symmetry inherent to special relativity (SR) whereby each observer measures the rate of the remote ‘moving’ ideal clock to be slower than the local ideal reference clock (i.e., each clock is falling behind the other clock). The algebra of the Lorentz transformations belies the fundamental underlying physically-real relative geometry of geometrically-distinct local space and time coordinates in spacetime. If two individuals starting from the same point each measure their progress in the plane in different directions (0 < Δθ < π/2) using odometers, then both odometers will display the same interval after each vehicle reaches the same arbitrary distance. The odometer readings are strictly-local measurements of progress, which is defined in a particular direction in space. Each odometer records the magnitude of the interval, but they do not incorporate any information about the corresponding direction vectors that are inherent to the measurement. Because each traveler defines progress in a different direction in space, each is entitled to state that relative to their strictly-local (i.e., “proper”) geometric definition of progress, the other individual has fallen behind in making such progress. Replacing the clocks shown in Fig. 8 with odometers and the time intervals with spatial
© 2015 A. F. Mayer 14 ver. 15.11.05.Z17 intervals, the symmetric geometric relationship between the two equal intervals (dtA, dtB) shown in the schematic illustrates the foregoing scenario of the two travelers. When one speaks of “proper time” in relativity, the origin of the term comes from the French as coined by Henri Poincaré (1854 – 1912) where the term “mon propre temps” in French literally means “my own time.” In accord with the fundamental principles and mathematical foundation (i.e., H. Minkowski) of relativity, the progress of an ideal clock’s “proper time” (i.e., it’s own time) is being recorded in a particular direction in spacetime. Recall from §Background that, rather than the conventional concept of a “3+1” manifold, spacetime is a physically-abstract four-dimensional manifold in which no dimension has a physical interpretation. Like an odometer, although a clock records the interval of time progression, it displays no information concerning the underlying geometry inherent to the measurement. However, when one observes the apparent rate of an ideal clock (B) in comparison to the proper time recorded by an ideal clock in the local frame (A) and finds that clock B is “falling behind” relative to the time recorded by clock A, one can state unequivocally that clock B is measuring an interval of time in a different direction in spacetime than clock A. This is patently obvious in the case of the symmetry inherent to special relativity, which is reified in the context of this intuitive geometric model (Fig. 8).
Symmetric relativistic temporal geometry in SR: geometrically, no ‘universal time coordinate’ exists in spacetime. A is “falling behind” B is “falling behind” the progress of B. the progress of A.
dtA dtB
" "
s
o os
c c B
v A t
sin! = ! " d dt
= = c B A
! !
1 d d sec! = ! # ζ 2 Euclidean 1" " spacetime Fig. 8
To reject this concept simply because it is not in the current textbooks reflecting prior thinking by respected authorities in the field is similar to a person of religious persuasion rejecting a new idea because it is not recorded in cannon law. Regardless, like Kepler’s three laws of planetary motion that effectively completed the Copernican revolution and laid the foundation for Newton’s comprehensive transformation of physics, this new idea leads to the prediction of subtle empirical observables that cannot be explained without it (i.e., observable effects of transverse gravitational redshift). In the idealized Euclidean (i.e., ‘flat’) spacetime of special relativity, the angle zeta (ζ ) is a simple mathematical function of the measured relative velocity (v) between two reference frames:
© 2015 A. F. Mayer 15 ver. 15.11.05.Z17 v sinζ = β → cosζ = 1− sin2 ζ = 1− β 2 • β ≡ (14) c
If the two distinct time coordinates diverge in spacetime by the angle zeta, the projection of the remote clock’s time coordinate on the local clock’s time coordinate corresponds to secant(zeta). Accordingly, the symmetric relativistic relationship between the respectively measurable frequencies of the two clocks (A, B) has a simple and intuitive geometric (i.e., physical ) interpretation, which is reflected in the definition of relativistic gamma. Note that the initial algebraic equality in Eq. (15), reflecting the inherent symmetry of special relativity, is sensible in the context of geometrically-distinct time coordinates in an idealized “flat” manifold (i.e., Fig. 8). This elegant mathematical symmetry cannot be achieved in the context of a spacetime defined such that all reference frames have universally collinear (i.e., parallel) time coordinates. Such a naïve temporal geometry (i.e., geometric model of time) having a single absolute time axis is inconsistent with abandoning the pre-relativistic Newtonian concept of absolute universal time.
dt dt 1 A = B = secζ = γ = ⎡dt = dt = dt = dt ⎤ 2 ⎣ A A B B ⎦ (15) dtB cosζ dtA cosζ 1− β
Special relativity is just as fundamentally rooted in geometry as is general relativity; the Lorentz transformation equations are merely a reflection of this underlying geometry in the four-dimensional spacetime manifold. Ironically, Einstein’s (i.e., Lorentz’s) algebra is really a misleading and somewhat superfluous mathematical formality as compared to Minkowski’s more fundamental, more informative and more physically-meaningful and accurate geometric expression of the theory.6 The concept of “curved spacetime” in GR arose from interpretation of its mathematical expression in the form of the Einstein field equations, rather than as an intuitive physical interpretation, but such an interpretation does indeed exist. The idealized condition of locally-Lorentzian space implies that the Minkowski metric (Eq. 16) applies locally within the neighborhood of any point, assuming a free-falling inertial reference frame. ds2 = −c2dt 2 + dr 2 + r2dθ 2 + r2 sin2 θ dφ 2 (16)
Accordingly, within this differential neighborhood, the locally-measurable time dimension (dt) is mutually orthogonal to the three locally-measurable space dimensions such that the strictly-local time dimension at each point may be globally defined in the context of geometry as the “local vertical” to the three-dimensional spatial ‘surface’ at every point. Clearly, physical (i.e., measurable) three-dimensional space is embedded in the four physically-abstract (un-measurable) dimensions of spacetime. The presence of mass causes this 3-manifold (space) to literally “curve” in the 4-manifold as a function of the
6 It is reported that a querulous young Einstein initially ridiculed Minkowski’s vital mathematical contribution to relativity as “superfluous erudition” (and subsequently never properly understood it). This occurred after Minkowski’s premature sudden death from appendicitis in January 1909. Source: Abraham Pais, Subtle is the Lord… The Science and the Life of Albert Einstein, (Oxford University Press, Oxford, 1982), p. 152.
© 2015 A. F. Mayer 16 ver. 15.11.05.Z17 radial coordinate (r). It follows that the measurable locally-orthogonal time dimension rotates with this curvature, just as the local vertical to a sphere rotates with the curving surface of the sphere. This ‘rotation’ in spacetime is a physical conversion of time into space producing the canonical “excess radius” ( ρ − Δr) of a gravitational field:
1 − R 2 R ⎛ S ⎞ ⎡ S ⎤ (17) ρ = ∫ ⎜1− ⎟ dr ⎢0 < ≪1⎥ ⎝ r ⎠ ⎣ r ⎦typical
The measured phenomenon of gravitational time dilation (Eq. 2), which is correlated to the Einstein redshift (Eq. 4), has been well-understood for about a century. The concept of relativistic temporal geometry (Fig. 9) correlates this empirical phenomenon with the rotation of the local time coordinate at some finite radial coordinate r (clock A) by a specific angle [η(r)] relative to that local proper-time coordinate corresponding to any inertial reference clock I at r→∞, where both clocks are collinear to the identical radial. This angle (~ 3.7E−5 rad on the geoid and ~ 2.1E−3 rad at the surface of the Sun) is defined in Eq. (18) and illustrated in the Fig. 9 schematic, which demonstrates that the angle between respective time coordinates for antipodal points at the same coordinate radius is zero by inverting the proper time vectors on the left hand side. Respective time coordinate arrows at the same coordinate radius on the left and right hand sides are parallel; two ideal clocks situated at antipodal points at the same coordinate radius in an idealized static, spherically-symmetric gravitational field (and, equivalently, on a spinning disk in the laboratory) are synchronous. The geometric relationships in 4-dimensional spacetime expressed by the general mathematics (e.g., Eq. 11) cannot be diagramed so that the corresponding arrows on both sides of Fig. 9 have the same orientation in the schematic, however the fundamental mathematical concept of relativistic temporal geometry in the context of the gravitational field can be intuitively illustrated as shown. Note the similarly between Eq. (14), which applies to special relativity, and Eq. (18), which applies to general relativity; the only difference between the two mathematical expressions is that the latter is defined in terms of a virtual (gravitational escape) velocity while the former is defined in terms of a real relative velocity between inertial reference frames. Both velocities represent a similar energy differential. v sinη = Β → cosη = 1− sin2 η = 1− Β2 • Β ≡ esc (18) c
According to the operative geometric principle (Fig. 9), ideal clock A, shown in blue, is “falling behind” ideal clock I, shown in red, which is serving as a reference. The absolute frequency ratio of the two ideal clocks is specified by Eq. (19), which is a function of the coordinate radius, per Β(r). A difference in coordinate radius r (i.e., vesc) between two points in a gravitational field implies preferred locations that can be distinguished by a difference in the respective local measurements of gravitational acceleration; thus, the symmetry of special relativity is lost.
© 2015 A. F. Mayer 17 ver. 15.11.05.Z17 2 dtI 1 2 ⎛ vesc ⎞ RS z = −1 = secη −1 = −1 • Β = = (19) E 2 ⎜ ⎟ dτ A 1− Β ⎝ c ⎠ r
Plugging the definition of Β into Eq. (19) yields Eq. (20), duplicating Eq. (4). As required in this case, one gets the same results as canonical GR, but in a much simpler way within the context of an intuitive geometric model for “spacetime curvature,” which has a direct correlation with the similar projective geometry of special relativity. dt 1 1 1 z = I −1 = −1 = −1 = −1 (20) E 2 dτ A 2µ R ⎛ vesc ⎞ S 1− 1− 2 1− ⎝⎜ c ⎠⎟ rc r
local proper time “coordinate time”
dtI η dτA
“flat” space “curve r→∞ d” spac μ Δρ I e A η→0 hips b = 0 relations r
The inherent parallelism of antipodal time coordinates, corresponding to a null geodesic through the center of mass (i.e., b = 0) having ideal spherical symmetry , is shown by inverting the antipodal mirror image of the above time coordinates. Re Eq. (11): if b = 0 then z = 0. t Fig. 9
Especially for an expert steeped in the complex and cryptic mathematical formalism (e.g., “index gymnastics”) of general relativity, the descriptive and predictive power of the foregoing intuitive geometric expression of the theory may not be immediately apparent. Both the newly-introduced underlying principle of relativistic temporal geometry and its most basic mathematical expression (assuming an ideal gravitational point source, which is the same facilitating simplification that was adopted by Karl Schwarzschild) are so extraordinarily lucid in comparison to the conventional approach that it may be easy for some to initially believe that this is all mathematical “smoke and mirrors.” Quite to the contrary, this approach provides important new physical insights into the phenomenon of gravitation, in particular a testable prediction (Eq. 11) of a previously unsuspected empirical phenomenon. And when it is verified by numerous empirical observations, the underlying theory must overthrow existing physical interpretations of general relativity. According to this reification of general relativity, the respective time coordinates of every unique point at rest in a static, spherically-symmetric gravitational field are geometrically distinct, with the noted exception of antipodal points at identical coordinate radius. Barring this exception, and within the boundary (r < ∞), no two such strictly-local time
© 2015 A. F. Mayer 18 ver. 15.11.05.Z17 coordinates are parallel in spacetime. In the context of relativistic temporal geometry, this non-parallelism implies a relativistic time dilation between the distinct reference frames associated with these time coordinates. The Eq. (12) integration, which yields an expression for the effective TGR angle between the distinct respective time coordinates of two arbitrary points in the external weak field, arises due to symmetry considerations. If the null geodesic between clocks passes through the source mass, the TGR effect is periodic over a circular path at fixed coordinate radius: initially, it rises with increasing arc length between clocks, attaining a local maximum prior to pi radians, and then falls to zero at the antipode to the reference clock (i.e., at pi radians when the null geodesic between the clocks passes through the centroid of the idealized point-source mass. Equations (9) and (11), which are radically different in form and in respective methods of derivation, represent the quantitative prediction of the identical observable, so they must agree, bound by the restriction [δ ≪ r] for the former equation. As has been shown, the former equation rests exclusively on the Einstein equivalence principle, while the latter rests on the new idea of relativistic temporal geometry applied to the gravitational field. According to the tenets of mathematical physics, nearly perfect agreement of these two distinct predictive equations implies that they can be relied upon to indicate that the underlying theory is correct. The possibility of two independently-derived formulas of this nature agreeing by chance to an extremely high degree of accuracy is virtually nil. For example, Eq. (5), which rests exclusively on the Einstein equivalence principle, is in very close agreement with the definitively-accurate general predictive equation for the phenomenon of gravitational time dilation (Eq. 22). This equation, which relates the relative frequency of two ideal clocks at different radial coordinates (r1 , r2) in the field, arises from Eq. (20), here rewritten in the form of Eq. (21). In Eq. (22), variable dt represents the rate of an inertial ideal clock in free space (i.e., r → ∞ , g → 0), and dτn represents the rate of an ideal clock at finite coordinate radius (rn) from an isolated ideal gravitational point source and at relative rest to the inertial reference clock. In canonical GR (the Eq. 21 equality on the left is typically derived from the Schwarzschild solution to the Einstein field equations), this relationship is independent of angular coordinates.
dt 1 dt = z = −1 (21) dτ R E dτ 1− s r
R R 1− S 1− S dt dτ dτ r r ⋅ 2 = 2 = 2 → z = 2 −1 (22) dτ dt dτ R E R 1 1 1− S 1− S r1 r1
The following Mathematica notebook (Math 1) compares the predictions of Eq. (5) with Eq. (22) over a 1-km vertical rise from Earth sea level. The last line indicates an error on the order of one part in ten thousand (~ 0.0175 %) for the result yielded by the familiar approximation (Eq. 5) as compared to the definitive value calculated according to the accurate canonical general formula (Eq. 22) for this empirically-verified phenomenon.
© 2015 A. F. Mayer 19 ver. 15.11.05.Z17 Math 1 Mathematica® notebook
The geometric parameters employed in the Math 2 calculations are illustrated in Fig. 10. The quantitative predictions of Eq. (9) and Eq. (11) are compared similarly to the comparison of Eq. (5) and Eq. (22) in Math 1. The last line of the Math 2 notebook indicates that the approximation formula (Eq. 9) predicting the TGR effect over a 1-km horizontal distance on the model geoid yields an error on the order of one part per billion (~1×10−7 %) as compared to the definitive value calculated according to the accurate general formula (Eq. 11). If the clock separation distance (δ ) is increased to 100 km, the error in the approximation rises to about 0.001%, which is still an order of magnitude less than the error in Math 1. To reiterate, there is no possibility of such a quantitative correlation having arisen by chance; it constitutes a virtual ‘proof’ that the mathematical physics is correct and that it accurately predicts an empirical phenomenon.
The Mathematica® EllipticE function (line 12) is described in the following URLs: http://reference.wolfram.com/language/ref/EllipticE.html http://mathworld.wolfram.com/CompleteEllipticIntegraloftheSecondKind.html
© 2015 A. F. Mayer 20 ver. 15.11.05.Z17 Math 2 Mathematica® notebook
Fig. 10
© 2015 A. F. Mayer 21 ver. 15.11.05.Z17 Part II: Empirical Predictions and Evidence
“See now the power of truth; the same experiment which at first glance seemed to show one thing, when more carefully examined, assures us of the contrary.” – Galileo Galilei, Discourses and Mathematical Demonstrations… (1638)
White Dwarf Stars One should expect to find compelling empirical evidence for the predicted relativistic transverse-gravitational-redshift effect in astrophysical phenomena. In particular, the unusually strong surface gravity of white dwarf (WD) stars must cause significant amplification of TGR as compared to normal stars: When it is possible to remove relative motion Doppler shift from the redshift measurement of a white dwarf, the remaining intrinsic redshift, which incorporates both Einstein gravitational redshift and TGR will have been interpreted as an Einstein redshift. Accordingly, the calculated mass of the WD according to the empirical measurement interpreted by Eq. (4) will have been considerably higher than that determined by independent means or as may be expected for the remnant of a progenitor star following a cataclysmic explosion (i.e., nova). It is remarkable that the “relativistic” masses of the white dwarf stars, which one obtains by reduction of the observed redshifts, are (on the average, with large scatter) significantly larger than the “astrophysical” ones… Various attempts to explain this discrepancy have been made in the past, e.g., by asymmetry-induced shifts due to slope of the continuum (Schulz 1977) but this problem still is not solved (see also the review by Weidemann 1979). In velocity units the systematic excess of the observed redshift amounts to 10–15 km s−1 (Shipman and Sass 1980; Shipman 1986) above “residual” redshift (i.e., redshift free of all kinematic effects).7 [ApJ (1987)] The primary method of determining white dwarf mass that has been established over recent decades is comparison of empirical spectra with spectral energy distributions of theoretical stellar atmosphere models. Newer models corroborating gravitational redshift measurements would yield masses considerably in excess of empirical reality as they do not incorporate the empirical TGR effect and these models would not accommodate all classes of white dwarf spectra; unphysical systematic effects in the M(Teff) curve for specific regimes (e.g., cooler stars of DA spectral class) would be inevitable. The TGR effect varies in magnitude, from zero for photons emitted from the center of the observed stellar disk collinear with the local gravitational gradient, to the maximum effect observed at the limb where observed photons are emitted orthogonal to the local gravitational gradient. Due to simple geometric considerations of the increasing annular area of constant-transverse-width rings of increasing mean radius (Fig. 11), the majority of a star’s observed photons, which dominate the spectroscopic redshift measurement,
7 B. Grabowski, J. Madej & J. Halenka, “The Impact of the Pressure Shift of Hydrogen Lines on ‘relativistic’ Masses of White Dwarfs,” ApJ 313, 750 (1987) < online >.
© 2015 A. F. Mayer 22 ver. 15.11.05.Z17 incorporate ‘excess redshift’ (i.e., excess to the Einstein redshift) due to the TGR effect. Additionally, the observed light of any distant star, resolved as a point source, has a corresponding continuous spectrum of redshifted wavelengths (TGR) superimposed on the Einstein redshift. Increasing TGR is incurred by photons originating from the star’s surface at increasing apparent angular offsets from the center of the (unresolved) projected stellar disk. Thus, TGR implies pronounced line broadening, which is a ubiquitous feature of white dwarf stars. This important distinguishing feature of white dwarfs is currently understood to be caused primarily by atmospheric pressure broadening, but there is reason to doubt this interpretation of the observable. Given the immense surface gravity of a white dwarf, it is unlikely that such an adequately-dense “atmosphere” would surround the star; its physical surface can be expected to be a sharp boundary between matter anywhere within the vicinity of the star and the vacuum of space. Although now generally accepted, such an unlikely theoretical ‘atmosphere’ surrounding a white dwarf can be perceived as an ad hoc invention that was required to explain the empirical observables without having the causal TGR effect quantitatively modeled or even suspected. Line broadening of white dwarf spectra due specifically to the modeled continuous spectrum produced by TGR must correlate to the calculated magnitude of the effect, which is a testable prediction. The following brief discussion clarifies the foregoing claims with explanatory detail: Although, with rare exception (e.g., HST image of Betelgeuse), all stars other than the Sun are resolved exclusively as point sources, it is a trivial fact that observed stellar radiation includes photons emitted from the entire projected stellar disk, including those specifically emitted from its center region and those distinctly emitted from the region adjacent to its limb. The majority of observed light emitted by a star originates from the distal area of the disk adjacent to the limb (Fig. 11). If the illustrated area ratios shown in this figure seem unintuitive, one may consider that the area of a disk (i.e., the orthographic projection of a ball representing a radiating star) is calculated by an integration of differential rings having width dr at radius r (Eq. 23). This intuitive and trivial integration makes it obvious that for constant dr the differential surface area of successive rings grows linearly with increasing radius.
R A = ∫ 2πr dr = π R2 (23) 0
Fig. 11
© 2015 A. F. Mayer 23 ver. 15.11.05.Z17 The measured non-Doppler redshift of a distant star resolved as a point source can be expected to reflect the majority of emitted photons, which are sourced from the more- distal region of the observed stellar disk, rather than its more-central region. The TGR effect implies a significant redshift of these photons superimposed on the Einstein redshift, yet the aggregate is currently assumed to accurately indicate a star’s mass- radius relationship by ostensibly measuring zE and solving for µ/r in Eq. (4). A naïve relationship between the mass and radius of a white dwarf (R ~ M −1/3) may be derived from minimizing the sum of its gravitational potential energy and kinetic energy, which is primarily in the form of degenerate electron motion (top curve in Fig. 12). Although this formula is simplistic, it clearly reveals the unintuitive fact that increasing the mass of a white dwarf reduces its radius. Correcting for the relativistic motion of the degenerate electrons in a white dwarf yields the lower curve in Fig. 12. The upper limit to the mass of an electron-degenerate object (~1.44 solar masses) is the Chandrasekhar limit (MCh), beyond which electron-degeneracy pressure cannot support the object against collapse.8