1. Introduction
The possibility of the variation of fundamental constants would impact all present physical theory, while all reported variations or interpretations of data concluding a constant has varied are extremely controversial. Examples of work in this area include Dirac’s Large Number Hypotheses [
1], the Oklo mine from which could be extracted a variation of the fine structure constant [
2,
3], and the observations of quasars bounding the variation of the latter per year to one part in 10
17 [
4,
5,
6]. Recent theoretical work includes the impact of time dependent stochastic fluctuations of Planck’s constant [
7], and the changes with Planck’s constant on mixed quantum states [
8]. An authoritative review of the status of the variations of fundamental constants is given in [
9].
Publicly available Global Positioning System (GPS) data was used to attempt to confirm the Local Position Invariance (LPI) of Planck’s constant under General Relativity [
10,
11]. LPI is a concept from General Relativity, where all local non-gravitational experimental results in freely falling reference frames should be independent of the location that the experiment is performed in. That foundational rule should hold when the fundamental physical constants are not dependent on the location. If the fundamental constants vary over larger scales than a locally flat frame, but their changes are small locally, then it is the form of the physical laws that should be the same in all locations.
The LPI violation parameter due to variations in Planck’s constant is called
βh. The fractional variation of Planck’s constant is proportional to the gravitational potential difference and
βh. The value found in [
10] for variations in Planck’s constant was |
βh| < 0.007. This parameter is not zero, and is the largest of the violation parameters extracted in the study. The study did not report on the altitude dependence of Planck’s constant above the earth. A very recent study involving the Galileo satellites found that GR could explain the frequency shift of the onboard hydrogen maser clocks to within a factor of (4.5 ± 3.1) × 10
–5 [
12], improved over Gravity Probe A in 1976 of ~ 1.4 × 10
–4, these are the
αrs redshift violation values that may be compared to
βh.
Consistent sinusoidal oscillations in the decay rate of a number of radioactive elements with periods of one year taken over a 20-year span has been reported [
13,
14,
15,
16,
17,
18]. These measurements were taken by six organizations on three continents. As both the strong and weak forces were involved in the decay processes, and might be explainable by oscillations of
ħ influencing the probability of tunneling, an all electromagnetic experiment was conducted, designed specifically to be sensitive to Planck’s constant variations [
19]. Consistent systematic sinusoidal oscillations of the tunneling voltage of Esaki diodes with periods of one year were monitored for 941 days. The tunnel diode oscillations were attributed to the combined effect of changes in the WKB tunneling exponent going as
ħ–1, and changes in the width of the barrier going as
ħ2. The electromagnetic experiment voltage oscillations were correctly predicted to be 180 degrees out of phase with the radioactive decay oscillations. This data can be made available for independent analysis by requesting it from the author of [
19].
It is reasonable to suspect that the oscillations of decay rates and tunnel diode voltage are related to the relative position of the sun to the orbiting earth, and that there are resulting oscillations in Planck’s constant due to position dependent gravitational effects, or effects with proximity to the sun. It should be mentioned that there have been studies in which it was concluded there was no gravitational dependence to the decay rate oscillations [
20,
21]. There is also dispute in the literature concerning the reality of the decay rate oscillations [
22,
23,
24].
Either way, whether by gravitation or by some other mechanism, for the work to be presented, all that matters is that there be a position dependent ħ, and it would be of value to understand the impact on the fundamentals of quantum mechanics and the Schrödinger equation under such a condition, and where conservation of frequency as opposed to energy will be explored as a means to retain Hermitivity.
For the treatment of
ħ in this paper, it is important to emphasize is not as a dynamical field, and leads to energy non-conservation. In another paper by this author, variations in
ħ are treated as a scalar dynamical field, coupling to fields through the derivative terms in the Lagrangian density [
25], and the energy is shared between the fields. One of the solutions of [
25] suggests that frequency may be a more fundamental dynamical variable than energy, leading to the idea of frequency conservation in this paper, where it arises naturally. This paper concerns issues specific to the Schrödinger equation in a single-particle, non-field theoretic framework, however. In
Appendix A of this paper, an attempt will be made to derive a classical field equation of motion (the Schrödinger field) resembling the frequency conserving Schrödinger wavefunction equation developed in the body of the paper, from two Lagrangian densities. The attempt will not be successful.
Variations in
ħ or any fundamental constant may be explainable by treatment as dynamical fields. On the otherhand, they may not be, especially where the spatial dependence is concerned, because there is so little experimental data on the subject. Noone knows with certainty whether they actually are dynamical fields, or not, though much work has been done representing some of them as dynamical fields: Jordan-Brans-Dicke scalar-tensor theory with variable
G developed in the late 1950’s and early 1960’s and note that
G is dimensionful; Bekenstein models with variable fine structure constant introduced in 1982 [
26,
27]; the Cosmon of Wetterich with a field dependent pre-factor to the dynamical terms functioning somewhat like Planck’s constant [
28,
29], falling to a constant value at high fields; the investigations of Albrecht, Magueijo, Moffat, and Barrow on variable
c used towards the explanation of the flatness, horizon, homogeneity, and cosmological constant problems [
30,
31,
32,
33]. For example,
Equation (i) shows in a single form an amalgam of possible couplings including a Jordan-Brans-Dicke-like scalar-tensor theory of alternative General Relativity with variable
G, an Albrecht-Magueijo-Barrow-Moffat-like field for
c, a field for
ħ like that of [
26], which is different than the form of Bekenstein’s for variable
e2 whose representative field squared divided the derivative terms. There is also the field theory of Modified Gravity (MOG) of Moffat, and the Tensor-Vector-Scalar (TeVeS) gravity of Bekenstein. There are many ways all the constants might be represented as fields, and many ways they might be coupled. Coupling fields together in this way is the accepted approach for the treatment of a constant, but is not the only possible approach, and here, something different will be tried.
What is to follow serves as a starting point for investigating what happens to the most familiar equations in physics, if Planck’s constant variations are that of a fixed-background parameter and not a field, and so there is no energy exchange between fields conserving the total. Instead, frequency conservation is explored, and energy is intentionally not conserved. In [
34] it will be shown that energy non-conservation leads to a possible explanation of the NASA Flyby Anomaly.
2. Derivation of the Expectation Value Time Derivative
The time derivative of expectation values for a position dependent Planck’s constant will be derived. No modification will be made to the form of the Schrödinger equation in this section, and the purpose is to make clear the difficulties that arise, and the special conditions that would have to be imposed on the wavefunction and Planck’s constant to maintain the basic framework of quantum mechanics. Then, a modification will be suggested.
Begin with the time-dependent Schrödinger equation in which Planck’s constant is allowed to be position dependent, and real,
The subscript
u indicates that the wavefunctions are un-normalized over space at any given time. To separate the time and position variables, divide both sides by
ħ,
Substituting (3) into (2) and dividing both sides by (3) gives,
where
ω is the constant of separation with units of frequency. The left-hand side of (4) has the solution,
and the right-hand side of (4) becomes
Defining the frequency operator
F,
Switching to the Dirac notation, Equation (2) becomes
Taking the complex conjugate of (8),
where the superscript †designates the adjoint operator acting to the right. The frequency operator is not Hermitian, noted from writing out in integral form the problematic part,
where the lower “.” indicates where the operator stops operating. The Hermiticity of the Laplacian has been used in (10), derivable by the use of Green’s second identity in the second to the third step, as long as products of
ħψ, and
ψ vanish at the boundary at infinity. The fourth step is what the answer would need to be in order to be Hermitian. Therefore, the frequency operator is non-Hermitian,
As a result, the normalization will not be conserved, and the frequency eigenvalues may be complex or imaginary. The rate of change of expectation values can now be derived using (8) and (9). The expectation value of an operator is,
where the denominator is the normalization, and normalization is redone continually for all times. Differentiating (12) with respect to time,
Working out the numerator of (13) and then using (8) and (9),
Therefore, from (14), the rate of change of the normalization is
Substituting (14) and (15) into (13) would give the full-time dependence of the operator
A, but this can be written in a cleaner way showing the extra terms that do not show up in normal quantum mechanics. To that end, remembering that
F is real,
so (14) in integral form is
Writing out the first term of (17), and of that, only the part containing the non-Hermitian portion of the frequency operator,
where on going from the second to the third part in (18), Green’s second identity was used again with
ψ and
ħAψ vanishing at the boundary at infinity. Note,
where the large dot between the gradients is the vector dot product. Equation (19) allows (17) to be written as a commutation relationship with extra terms. Defining the functional,
and from (20) follows the time dependence of the normalization,
Combining (20), (21) and (13), the result is,
The second term of (23) appears because F is not Hermitian, and were it not there, (23) would look like the result of normal quantum mechanics.
7. Lack of Conservation of Energy, Momentum, and Ehrenfest’s Theorems under Fh
It is not a surprise, given the loss of translational symmetry in the absence of a potential, that momentum should not be conserved, per the results of Noether. In addition, energy is also not conserved, stemming from the lack of a Lagrangian, and action, whose variation could lead to (33) and (34). To continue the analysis, it is easiest to use the most basic methods of quantum mechanics.
Using (36), (38) and writing
V/ħ = Fh − Wh one sees that,
So that V/ħ is “potential frequency” and Wh is “kinetic frequency” acting together to conserve total frequency as the particle moves. Energy is not conserved now, and in addition, even if the particle is free, the momentum is also not conserved, both changing value with position in the absence of an external potential. Frequency, however, is conserved. Changes in V/ħ from a starting to an ending position is the frequency equivalent of work done on or by the system.
On examining the free particle operator
Wh, this author is unable to identify a simple operator for momentum. In light of (51a), a possible momentum operator is (51b),
Although the square root operator is difficult to work with, it could be definable in terms of Fourier transforms. Lacking an operator for the momentum implies there is no relation equivalent to Newton’s first and second laws between expectation values as there is in normal quantum mechanics with Ehrenfest’s theorems. An attempt at a connection with normal quantum mechanics is made by borrowing its momentum operator, but now with a position dependent
ħ,
from which can be defined a wavenumber operator,
An infinitesimal displacement operator can be defined as
By inspection, the free particle operator
Wh is not generally invariant to the infinitesimal displacements owing to
ħ(
x), therefore,
So neither momentum or wavenumber are conserved by the definitions of normal quantum mechanics by this symmetry argument, for a free particle.
While (56) looks simple enough, the first term is complex, and the second term is always imaginary. It has not been shown whether the imaginary parts of (56) generally exactly cancel for any arbitrary choice of ħ. For the free particle of (47) with its very mild ħ gradient all is per the norm, as the imaginary terms that result in (56) do exactly cancel, and the righthand side equals ħok/m. For the particle in a box with a slight ħ gradient of (49) and full solution, it has not been shown that all eigenstates lead to a real result for (56).
Equations (56) and (57) reduce to the normal Ehrenfest’s theorems for constant ħ, but do not appear like them, otherwise.
So, while particle frequencies are conserved, and local energies, probabilities of particle location, and average values of quantities can all be computed and are real, there seems to be no assured connection with classical dynamics. The position expectation value time derivative being complex or imaginary is difficult to interpret. Consider an analogy in classical mechanics, where a particle sits at the bottom of the harmonic oscillator potential with zero energy and velocity. Integrating the equations of motion, one finds for the velocity v = (−kx2/m)1/2. If the particle is then suddenly found at any position other than x = 0 with no source of energy, the particle velocity is imaginary, and the magnitude of the imaginary velocity tells you the extent of the energy non-conservation.
This model may be producing complex position expectation value time derivatives, generally. With a conserved frequency and a position dependent ħ, this suggests ħ is a minimum at some position in space that serves as the reference of lowest energy, meanwhile the particle wavefunctions may extend to locations where ħ and energy are larger. Then, the particle has a finite probability to be observed in both high and low energy locations. Complex values of (56) and (57) signify that the particle is forbidden to be there in classical mechanics, and normal quantum mechanics, but is there anyway.
The lack of conservation of energy, while something that is difficult to accept based on the heritage of its use as a guiding law, is not yet a reason to abandon a model. The uncertainty principle, virtual mediating particles, conservation of energy only in locally flat frames in GR, lack of conservation of energy in dynamic spacetimes, and the cosmological constant all attest.
12. Discussion
Field Theory and General Relativity are the cornerstones of modern physics. There seem to be some inherent contradictions in both theories. For example, in field theory, a static field functions much like the fields as envisioned by Faraday. Yet, a static field can be approximated with the tree-level terms of the perturbative expansion to produce an amplitude, with Feynman diagrams showing particle exchange limiting the interaction to the speed of light, equated to the Born approximation amplitude to produce a classical potential. Propagation of a field would therefore appear to be required for the static field to function. For a black hole, the mass, charge, and angular momentum are not censored: they are communicated by non-propagating modes in field theory, the accepted explanation. Changes in the static fields are propagated at the speed of light, but once reestablished, are Faraday-like static fields once again, influencing instantaneously at a distance. Physical constants would be static fields, and like any static field, described by non-propagating modes, Faraday-like, influencing instantaneously at a distance. When matter or charges gravitate into the event horizon of a black hole, the initial non-propagating modes, understood to have been set up long ago, quickly readjust, to produce the new non-propagating mode. Yet, the despite the censorship of the event horizon, somehow, in the particle picture, particles (fields) must propagate from the event horizon to reset the non-propagating modes – thus emission of particles from the horizon would seem to be needed. The descriptions conflict, despite the predictive power. As for General Relativity, it is perfectly acceptable at this time, that energy and momentum are not conserved when there are dynamical changes in spacetime, although how the non-conservation evolves is well understood, with the conservation possible only in a locally flat frame. With a cosmological constant, the total energy of the universe increases (explained by negative pressure). The variation of physical constants throughout the universe may also constitute acceptable violations of conservation laws.
Many persons maintain the position that the measurement of a single dimensioned constant in isolation is not physically meaningful, and the only meaningful measurements to be made are those of dimensionless products of the isolated dimensioned constants. The reason given is that the dimensionless constants are free of units that rely on arbitrary standards, and on calibrations of the metrology tools based on them. Both may be influenced by the variation of the constant itself, and also the measurement always involves multiple mechanisms with which other constants are convolved.
The above philosophy is sound when the metrology tools are located in the same place that the physical constants may be varying in, and only one technique is used for the measurement, and that single device-type is changed by the variation itself, and if the standards on which the calibrations are based are in flux. However, it has not yet been experimentally borne out whether multiple techniques used in coordinated concert in the same location could, or could not, attribute the results of all the techniques to a single isolated dimensionful constant changing. It is also possible that a specific experiment could be devised at some point that is sensitive to only one dimensioned constant and designed not to be disturbed by the constant’s variations.
An extreme example is to ask what would happen if Planck’s constant doubled in the sun, but not on the earth? Would there then be a discernable effect or not, would it be detectable from the earth, could it be determined that it was Planck’s constant that was the single constant that had changed, and would it then be worthwhile to attempt to measure the change in isolation?
Suppose that the spatial variation of a physical constant is very gradual, so that locally, it is as if the dimensioned constant were approximately constant, such as the case developed in
Section 6 of this work. Then the form of the local physical laws would be the same in the two remote locations X and Y, but the dimensioned physical constants would be different. Experimenters in location Y could make observations on emissions from X with their metrology, exploiting invariants, and communicating results to one another.
Particles emitted from X with local energy EX traverse the mild ħ-gradient to Y with fixed total frequency ω, where its local energy EY can be measured. With no external potential active in the traversal (or the impact subtracted out if there is one), there will be an energy change ΔEYX = ΔħYXω due to the ħ gradient. If experimenters in X and Y communicate and both agree on the frequency and report the local energies, the differences measured in ħ in X and Y could be confirmed. While this may be difficult to arrange, in principle, it can be tested.
According to the model developed here, a particle conserves energy and momentum, and obeys Newton-like laws only locally for a small enough gradient in ħ. This limit is consistent with the tenet that the laws of physics be the same in all locations. Energy conservation and free-particle momentum conservation would become local laws, not be upheld at greater scales. At large scales, energy and momentum are definable artificially in terms of the normal quantum mechanical operators. For a sufficiently mild ħ gradient, quantum mechanics becomes, locally, per the norm, energy is conserved, frequencies can change, redshifts can occur, position expectation value time derivatives are real, and momentum is an entity.
Though energy would not be conserved over large scales, X cannot benefit by any energy gain at Y, since returning the particle from Y back to X returns it to its original local energy. One may also contemplate manufacturing processes of various sorts, where at Y is required greater work (cost) to execute, relieved by less work (cost) in transporting the items to X. The situation is the opposite for items produced at X then transported to Y. In either direction there is a cancellation effect.
There is the result from this model that free particles have a higher probability to be found in regions of lower ħ. If it were found that ħ were lower near large masses, then in the absence of an external potential there would be a quantum mechanical reason for mass to tend to locate near other mass. If the opposite, there would be a quantum mechanical reason for mass to avoid mass. One may contemplate whether the seeds of the large-scale structure of the cosmos was due to the variation of a constant, driving matter to collect at the seed origin.
The model requires the definition of a local potential energy
V to be put into the frequency operator, and, there are difficulties with Ehrenfest’s theorems, as far as identifying a straightforward relationship with classical mechanics. It was rationalized there is some reference point in space in which
ħ is a minimum. The latter is the classical limit, or more precisely, the limit when the classical action
Sc >> ħ. In the latter, it is not that
ħ is actually going to zero, rather, masses and kinetic energies are getting very large, and the classical behavior is recovered. In the model of this paper, it is suggested that should
ħ be found to vary spatially anywhere, then somewhere else
ħ is minimum. Recall in the result of
Section 6 of this paper, that wavefunctions are concentrated in areas of lower
ħ—particles would want to collect in those regions, for reasons beyond gravity, and in collecting, also approach the classical limit.
It would be desirable to find some physical system in which
ħ depended on position to test the model, and this is taken up in [
34] in the analysis of the flyby anomaly, and Hulse-Taylor-like binaries. There, the effects of a position-dependent
ħ may be apparent over larger scales.
The first experiments one might consider are those that have been performed already, involving atomic clocks on satellites in orbit about the Earth [
10,
11]. Increased precision of the instruments may be required to make an undisputed measurement of the variation of a quantity like Planck’s constant. The author wonders if variations in Planck’s constant, measured with clocks and light, might be somehow be suppressed in some cases, and a scheme is suggested below for how this might happen.
An argument will be offered for how a position-dependent Planck’s constant may appear to not violate local position invariance, and how it may appear to be consistent with the Einstein Equivalence Principle, based on experiments, on scales where the observations are not restricted to locally flat frames, involving clocks and light. The argument comes by way of an often-seen pedagogical derivation of the gravitational redshift without full general relativity, and is used here, because at present, there is no higher theory for frequency-conserving Einstein field equations. The prescription leads to the correct formulae given by the higher theory to first order.
Consider a photon falling into a gravitational potential due to its “gravitational mass” m(r) = ħ(r)ω(r)/c2, analyzed as if conserving total frequency ΩTOT = ω∞, not total energy. The Newtonian field for a spherical mass of g = −GM/r2 is integrated from ∞ to r to produce the gravitational potential φ = −GM/r, which is then multiplied by the gravitational photon mass, but without inclusion in the prior integration. This approach produces the result of GR for the gravitational frequency shift to first order. So, with no higher theory of a total frequency-conserving stress tensor, the sum of the kinetic frequency and potential frequency are per (65b), from which (65c) follows. Kinetic frequency is what is measured. Note that ħ(r) has cancelled in (65c), and is precisely the same expression derived when ħ is constant. Equation (65a) is the usual expression from GR for a constant ħ, conserving total energy.
If the falling photon is analyzed as conserving total energy
ETOT = ħ∞ω∞ with a position dependent
ħ, then (65d,e) results. A functional form of the LPI violation for
ħ∞/h(
r) is chosen to resemble (65a), written with the Schwarzschild radius
RS = 2
GM/
c2. If total frequency is actually conserved and not total energy, the value of the LPI violation parameter
βh returned will be zero, even if
ħ is not constant (at least to first order).
Equation (66) reduces to the expression in the limit of small deviations seen in [
10,
40], where Δ
U is the gravitational potential. Equation (66) was written to match the expressions of [
10,
40] in the limit, to allow an analysis on the available data, looking for problems. A systematic dependence of
ħ on altitude was not developed in [
10], only that there was a variation with a range per (66) with |
βh| < 0.007.
Table 1 summarizes the findings of (65a–e), and it is concluded it may be difficult to detect the variation
ħ(
r) using falling light or clocks at different altitudes, if total frequency is conserved, even if
ħ truly varies. Tests such as the Pound-Rebka experiment, and observations with clocks on satellites at different altitudes may be completely insensitive to the variation, as such.
Consider the following thought experiment. Bob is inside a closed elevator in the vicinity of the Earth, held on a rope by an immobilized Alice, above. They both have a clock, which is a perfectly interior-reflecting box of trapped light of frequency
ω that they can each measure. If total frequency is conserved, by
Table 1, whether
ħ varies or not, or whether Alice slowly lowers Bob, or cuts the rope and allows him to freefall, he will register no change in the frequency of his own clock, and since he cannot see emissions from Alice’s clock, he registers no perception of any difference. Thus, the Einstein Equivalence Principle would be apparently consistent, as would the local position invariance of
ħ, since when the two clock readings are compared later when Alice and Bob communicate, they will show only the differences predicted by normal GR, whether
ħ varies or not. Now, let Bob kick the box with a known force parallel to the floor of the elevator at several different altitudes in a gradient in
ħ. Though the frequency of light in the box to Bob is fixed, the energy of the light in the box is not, hence its gravitational mass changes, as does the result of the kicking experiment as a function of his altitude. Since the result of the kicking experiment varies with his position in spacetime, and the experiment is not gravitational, both the Einstein and Strong Equivalence principles do not actually hold (unless the former is interpreted to hold, if the kicking of the box is interpreted to be a gravitational experiment, since it measures the gravitational mass and inertial mass simultaneously, or if the experiment is considered to be greater in scale than a locally flat frame, as he must kick when he knows he is in a different spacetime position to register a difference). The Weak Equivalence Principle will still hold, despite that the mass of any object becomes position dependent due to the variation of
ħ, and despite that different substances will show different ratios of mass change – gravitational and inertial mass are still equal.
Reference [
34] shows that objects in non-circular orbits, or elliptical orbits, will enhance the effect of a position dependent Planck’s constant, especially a flyby orbit, as a hyperbolic orbit cuts through the isocontours of Planck’s constant maximally. The analysis of an entire orbit is a larger scale experiment, from which the variation in Planck’s constant can be detected.
The discussion will continue as if energy is conserved. Using |
βh| = 0.007 and the mass and radius of the Earth, (66) results in very small fractional changes near the surface of the Earth relative to infinity, on the order of one part in 10
12. The form (66) does not persist beneath the Earth surface due to volume filling matter. The same order of magnitude for the fractional change is found in the ratio of
ħ at the maximum and minimum radii of the Earth’s orbit around the sun. These variations are four orders of magnitude lower than the very best terrestrial laboratory measurement capability, achieving on the order of 10
–8 relative uncertainty using the superconducting Watt balance [
41]. Therefore, the authors of [
10] may have used the GPS data to attempt to measure changes four orders of magnitude smaller than the capability of the very best earthbound metrology, if Equation (66) is operative.
The variations taken from (66) are much smaller than the 21 ppm peak-to-peak
ħ variation extracted from the electromagnetic experiment (850 ppm peak-to-peak annual diode voltage variation) in [
19], and the 1000–3000 ppm peak-to-peak annual variations of the decay rates in [
12,
13,
14,
15,
16,
17]. Were Equation (66) actually operative, completely different mechanisms would have to be at work than those in [
12,
13,
14,
15,
16,
17] in its relation to [
19], or
βh would have to be 7 to 9 orders larger to account for the difference. At the surface of the sun using |
βh| = 0.007 the fractional change in
ħ is 1 part in 10
8, getting closer to the relative uncertainty of the best terrestrial measurement. Thus, (66) may not be the correct description, in light of all the data from the two experiments.
The latter two paragraphs merely underscore that the measurement of variations in a constant such
ħ is in its infancy, its dependence in a gravitational field is unknown, and more experimental work is needed to gain traction. A reanalysis of the GPS data per [
10] up to the current date to refine
βh and look specifically for a systematic change in
ħ with altitude may be worthwhile. An independent analysis of the data of the diode experiment in reference [
19], along with analyses of the theory of the measurement are both needed. Repeats of all of the experiments by independent investigators with higher precision equipment would be critical.