Problems If Photons Gain Or Lose Energy with Changing Gravitational Potential

RELATIVITY WITH A QUANTUM FIELD

David W. Talmage [email protected]

Abstract. A sharp distinction has been made between the confirmed observations that were predicted and form the essential core of the theory of relativity and the untestable explanations that have become the lore of the theory and its vision of reality. The possibility is explored that it is these explanations, not the observations, that are incompatible with quantum mechanics. The explanation of the gravitational red shift, that photons lose energy as they climb out of a gravitational gradient, is the keystone to this lore. Once this keystone is removed the remaining explanations lose their coherence. Alternate explanations are presented that are not only compatible with quantum mechanics but require the existence of a quantum field.

The two greatest discoveries in physics in the 20th century were relativity (SR and GR) and quantum mechanics (QM). The predictions of both theories have been confirmed by many observations. But despite repeated attempts by Einstein and other relativists and by quantum physicists, two of the theories (GR and QM) have never been unified with a single view of reality(1,2). These attempts at unification have been largely mathematical. The present paper explores the possibility that the failure to unify the theories is the result of a mistaken view of the reality that explains the observations of relativity.

The most important confirmed predictions of relativity (SR and GR) are that (1) mass increases with motion and is interchangeable with energy; (2) there is an exact equivalence between the gravitational and inertial masses of all matter, (3) clock rate decreases with motion and with a decrease in gravitational potential (altitude); (4) the measured speed of light is the same in every inertial and gravitational frame of reference; (5) light coming from a source with a lower gravitational potential is shifted toward the red; and (6) a star observed near the rim of the sun during an eclipse is displaced away from the sun by 1.75 arcseconds. It seems likely that the relativity theories were developed when Einstein was under the influence of Mach’s positivism and were not intended to be more than a description of what would be observed. Thus, two observers moving relative to each other could both observe the other’s clock running slower than their own without producing a logical inconsistency.

Problems with the unification of QM and relativity have arisen because interpretations of the equations of relativity have been made which impute a causal reality that cannot be tested by direct observation. For example, relativists generally claim that the relativity theories show that (1) the gravitational red shift is caused by the loss of energy in photons climbing out of a gravitational gradient; (2) the kinetic energy of a falling body of matter is derived from the gravitational field (3) the speed of light is constant; (4) the displacement of a star on the rim of the sun is caused by a curvature of space-time; (5) there is no preferred frame of reference and thus all motion is relative; and (6) the observed increase in mass of a speeding particle of matter is caused by its motion relative to the observer. These six interpretations of the relativity theories are interdependent, internally consistent and compatible with the predicted observations. The possibility that they are false and create insuperable problems to the unification of relativity and QM is the subject of this essay. I will try to show that an alternate view of the reality behind the observations predicted by Einstein is not only compatible with but dependent on QM.

The cause of the gravitational red shift

The relativistic explanation for the observed gravitational red shift is that photons rising through a gravitational gradient spend some of their energy(3). Conversely, photons moving down the gradient are thought to pick up energy. This view of reality may be derived from the observation that energy must be applied to matter particles to push them up the gravitational gradient, and matter particles falling down the gradient acquire kinetic energy. But unlike matter particles which require an external source of energy to climb the hill, photons would have to radiate some of their own energy spontaneously. And photons would have to absorb energy from the gravitational field as they move down. This raises some important questions.

Where does the energy go when photons lose their energy and where does the energy come from when they gain it? Why don’t matter particles, which are composed of energy, also radiate energy when they climb a gravitational gradient and where does the kinetic energy come from when they fall? Why do matter particles need an input of energy to go up hill and why do they develop kinetic energy going down hill, which is different from the relativistic view of what happens to photons?

Why is the gravitational field never absorbed by the matter that responds to its force? Why is there a correlation between the amount of red shift and the reduction of clock rate at the lower gravitational potential?. Why does the speed of light appear to be reduced rather than accelerated as photons pass by the sun? Is there an alternative explanation of the gravitational red shift?

One alternative explanation of the gravitational red shift is that the photons radiated from matter at a lower gravitational potential are already red shifted at their source. They are red shifted because the matter particles from which they originate are on a slower time as demonstrated by their slower clock rate. Thus, the photons do not need to lose energy on their way up hill in order to be red shifted. The correlation between the kinetic energy developed during the fall of matter and the reduction in its clock rate suggests that particles of matter require less rest mass/energy at a lower gravitational potential than similar particles at a higher potential. This would explain why the radiated photons have less energy at a lower potential. It also explains why matter particles require an external input of energy to climb a hill and why they release kinetic energy when they come down. Photons, however, unlike matter particles, do not have a specific energy requirement at any potential and should be able to travel up and down without a change of energy.

The alternative explanation postulates that neither photons nor matter particles exchange energy with the gravitational field and that the kinetic energy is derived from a reduction in rest mass. Although the small reduction in rest mass that would go with the reduction of gravitational potential has not been detected, the loss of rest mass by the much greater release of nuclear energy has been observed. And the proposal that matter responding to the gravitational field does not absorb energy from the field can explain why the gravitational force is not absorbed. And this difference between the gravitational and the electric fields might explain why the force of gravity is weak relative to the other forces. The correlation between the reduction in the speed of light and the reduction in clock rate will be discussed in the next section.

The speed of light

Speed is the number of distance units traveled per unit time. Thus, the values obtained from the measurement of speed depend on the units of distance and time that are used. The evidence that light travels at a lower speed near the sun than it does on the earth’s surface is found in the results of the experiments by Shapiro and coworkers(4, 5). They measured the time required to bounce a pulsed light beam off Venus, Mercury or a Viking spacecraft and return. As the path of that light beam came close to the sun, there was a measurable increase in the lapsed time, as determined by clocks on the earth’s surface and thus was expressed in units of time that obtain there. It was assumed that the distance in earth units was not increased by the fact that the light beam passed near the sun and corrections could be made for any changes in distance caused by the shape of the orbit. Shapiro expressed the result as a time delay because he did not want to say that the speed of light changed. However, a time delay over a constant distance is equivalent to a reduction in the speed of light. Relativists could say that the speed of light is constant if the result is expressed in the proper units that obtain at the rim of the sun. But the speed of light is reduced at lower gravitational potentials in the same sense that the clock rate is reduced. It is important when comparing two clock rates or two speeds to use the same units of measurement in both cases.

When the changes in the speed of light and in clock rate are compared, it has been determined that the fractional change in the speed of light is twice the fractional change in the clock rate. Shapiro explained this difference by invoking an unobserved change in distance that was symmetrical with the change in time. This implies that the change in the speed of light is the primary effect of the gravitational gradient and that the changes in time and distance are secondary effects.

There is one other reason to conclude that the speed of light changes with gravitational potential. This is that the measurement of the speed of light is constant. Since it is known that clocks move slower at lower potential, there would be a change in the measured speed of light if the real speed did not change to compensate. Thus, the lack of a change in the speed that these changed clocks measure is evidence that the speed of light changes.

The displacement of stars on the rim of the sun and the curvature of space-time

This displacement is the prediction that made Einstein famous. The amount of the displacement predicted by Einstein has been confirmed repeatedly by observation. At first Einstein attributed the displacement to a reduction in the speed of light(6), and only later attributed it to a curvature of space-time around the sun. There are two reasons to think that his first explanation was correct. The first reason is that the amount of displacement is exactly the amount that would be expected if the speed of light followed a least time path and is reduced by the amount that can be deduced from Shapiro’s observations(7). The second reason is that quantum mechanics requires that light follow a least time path(8). Any other explanation would make General Relativity incompatible with QM.

Relativity of motion and the existence of a preferred frame

If there is a preferred frame of reference in which the speed of light is isotropic, it is impossible to detect linear motion relative to this frame with laboratory experiments. One observation that suggests the existence of a preferred frame is the asymmetry of the cosmic radiation that indicates that the solar system is moving through the frame of that radiation at approximately 0 .001 times the speed of light. Another observation is that, as predicted by Einstein, the speed of light is independent of its source. This is confirmed by observations of double stars, where the motion of one star is moving away from us when the other is moving toward us. Despite this reciprocal motion the timing pattern of the Doppler changes is maintained over millions of years of travel. This would be possible only if there was a frame of reference in which all the photons traveled at exactly the same speed..

A very important argument in favor of a preferred frame is that such a frame can be detected in rotational experiments, such as the Newton bucket experiment, the Foucault pendulum, the Hafele-Keating experiment(9) and the Sagnac effect(10). Furthermore, the aberration of star light, first observed by Bradley(11), depends on the revolution of the earth around the sun, and is independent of the motion of the source star. The existence of such a rotational effect is evidence that the visible universe provides a frame of reference which determines the difference between straight and curved motion.

Fitzgerald and then Lorenz and Poincare(12) suggested that the detection of linear motion in a preferred frame is prevented by changes in the units of time and distance that cancel the effect of changes in light speed. The fact that changes in clock rate with motion have been repeatedly confirmed provides ironic evidence that the preferred frame exists. When Einstein was alive clocks were not accurate enough to detect the changes in moving clocks and the changes could be considered as only appearances. Now that we know they are real(13), their existence would produce differences in the measurement of the two one way speeds of light unless there was a real change in the speed of light to cancel their effects.

The increase in inertial mass of a speeding particle

This prediction has been confirmed repeatedly in particle accelerators where corrections need to be made for the changes in mass of accelerated particles. The charge on particles such as electrons and protons remains constant and the ratio of mass to charge is increased as the speed of the particle approaches the speed of light. Since relativists generally consider that all motion is relative they must attribute the increase in mass to an apparent effect of the motion of the particle relative to the observer. There is an alternate explanation to the mass effect. This is that there is a preferred frame that is undetectable because changes in clock rate and distance produced by motion exactly cancel any attempt to detect it. Since changes of mass are very small at the presumed low speed of our solar system, it is impossible to determine whether the changes of mass seen in the particle accelerator are the result of motion relative to the observer or relative to the undetectable preferred frame.

The quantum field

Quantum mechanics and the uncertainty principle require the existence of a quantum field of virtual particles surrounding all matter and energy(8). Unlike the field surrounding electrons the field around neutral particles would not be charged, but like the electromagnetic field the density of the field should decrease with distance from the source particle. Thus, the quantum field would possess a gradient around massive bodies. If the density of the quantum field around charged and uncharged matter particles decreases as the first power of the distance, the gravitational and electromagnetic forces, which are based on the slope of the gradient, would be, as we observe, inversely proportional to the square of the distance. Another consequence of the inverse first power decrease of the gradient is that distant objects of the universe would have a major effect on the density of the quantum field. This is because the total mass of distant bodies increases as the square of the distance while the per unit effect of that mass decreases by the first power of the distance. The quantum field produced by distant bodies would be undetectable because there are distant galaxies in every direction, which prevents the existence of a significant gradient. However, the quantum field from the universe would be very large compared to that of local masses and could provide the preferred frame against which inertial forces develop.

The cause of inertia and its unification with gravity

The exact equivalence of gravitational and inertial masses suggests that gravity and inertia have a common cause. If this is so then inertia and gravity are both produced by the same field.. The most likely candidate for such a field is the quantum field. The proposal that the primary effect of the quantum field is the control of the speed of light provides a possible explanation of both gravity and inertia. In the case of gravity matter particles respond to the change in the speed of light caused by the gradient in the quantum field, whereas with inertia a change in the motion of the particles relative to the preferred frame of the quantum field produces a change in the speed of light relative to the particle.

Discussion

The observable predictions of the relativity theories have been confirmed beyond any reasonable doubt. It is the untestable explanations of these predictions that have been challenged here. An alternate reality to six of these explanations is .presented that is not only compatible with quantum mechanics but uses the quantum field to explain gravity and unify it with inertia. The explanations given by relativists for the same set of observations are interdependent and internally consistent. For example, if you accept the explanation of the red shift, that photons lose energy as they climb a gravitational gradient, it is logical to believe that the kinetic energy of a falling object is derived from the gravitational field. This denigrates the importance of the reduction in clock rate and leads to the belief that the apparent changes in clock rate and light speed are only appearances. If the speed of light is constant in all frames of reference then there is no preferred frame and all motion is relative; Paul Davies in his “Confessions of a Relativist” admits that understanding relativity has required, for him at least, to give up all ideas of common sense and visions of reality(13). I believe that the alternate view of relativity presented here permits a vision of reality that makes sense. Several key observations made since Einstein’s death utilize atomic clocks that possess an accuracy undreamed of during his life time. With these clocks it has been possible to distinguish between the reality and the appearance in Einstein’s predictions(14). Clocks really do run more slowly when moved and when placed at a lower gravitational potential. By bringing the clocks back to their original position and comparing them to clocks that have remained there, it has been possible to show that it is the motion and the low gravitational potential that make the clocks move more slowly, not the acceleration. From this firm foundation the following alternate view of reality has been developed: (1) Neither photons nor matter particles exchange energy with the gravitational field; (2) A change in the speed of light is the primary effect of the gradient in the gravitational field; (3) Secondary effects of the change in the speed of light are gravity, inertia, the observed change in the clock rate and the unobserved contraction of distance; (4) the displacement of stars on the rim of the sun is also an effect of the change in the speed of light; (5) there is a preferred frame of reference against which inertia develops, but linear motion in this frame is undetectable in laboratory experiments because of compensating changes in time and distance; (6) the change in mass of a rapidly moving particle is a result of motion relative to a quantum field created by the visible universe. There are five relevant correlations that in a random universe should logically indicate a causal relationship. These are (1) The correlation between the fractional reduction in clock rate and the fraction of total energy in a matter particle that is released as kinetic energy when a matter particle drops to a lower gravitational potential. (2) The correlation between the fractional reduction in clock rate at a lower gravitational potential and the fractional reduction of the energy of photons as calculated from the red shift. (3) The factor of two correlation between the fractional change in the speed of light, as determined by the time delay of light pulses passing by the sun, and the fractional change in the clock rate of matter particles. (4) The inverse correlation between the increase in mass of an accelerated particle and the decrease in its clock rate. (5)The identity of the gravitational and inertial masses of all matter. All five of the above correlations are predicted by the relativity theories and have been confirmed by observation, but they have not been given causal interpretations. They have all been important in the development of the alternate view of reality presented here. If there is any question about the accuracy of these correlations further experiments could be devised with the very accurate clocks now available. And the equivalence of gravitational and inertial masses might be tested further on spacecraft circling the earth. For example, since heating a particle increases its inertial mass, heating it should change its orbit around the earth unless the gravitational mass also increased proportionately. REFERENCES 1 J. Maddox, Scientific America. 281, 62-67 (1999) 2 C.Isham, The New Physics, edited by P. Davies (Cambridge University Press, 1989), p. 70. 3 C.M.Will, Was Einstein Right, (Basic Books, Inc. N.Y. 1986) p.49. 4 II. Shapiro et al., Phys. Rev. Lett. 13, 789 (1964) 5 R.D. 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