By Robert M. Hartranft, Jr., Consulting Engineer, Simsbury, CT 06070
Scott W. Hartranft, Test Engineer, Tektronix, Inc., Beaverton, OR 97077

 
Suppose there are two kinds of matter. First, all the matter people normally encounter or consider, including ordinary anti-matter: it has positive mass, positive energy, and positive momentum (that is, momentum in the direction of velocity). This includes protons, electrons, positrons, quarks, photons, and all the other usual particles. Call this "M" matter. M matter gravitationally attracts other M matter.

But suppose there is also a symmetric class of matter, which we will call here "U" matter, for Unmatter. Particles of unmatter would have negative mass, negative energy, and momentum opposite the direction of motion. Unmatter would gravitationally attract other unmatter, but for reasons discussed later, would gravitationally repel M matter.

Space-time is the zero energy plane in this model.

Suppose further that at Planck scale [i.e., 10^(-35) meter and 10^(-43) seconds], there could propagate tiny ripples in space-time, each such ripple consisting of a slightly leading M component and a slightly trailing, but otherwise symmetric, U component. We will discuss below how such ripples could function as M gravitons. Note that the net mass, energy, and momentum is zero for such gravitons. U ungravitons would have a slightly leading U component, but again, net zero mass, energy, and momentum.

The Big Bang

Suppose that at the start of the Big Bang, the creation event produces precisely equal amounts of M matter and U unmatter. The universe will therefore start with a net mass of zero, a net energy of zero, and a net momentum of zero. Because there are equal amounts of M matter and U unmatter, the net gravitational force will also be zero. Assuming charge symmetry, the electromagnetic force will also net to zero. But things will be very crowded by nuclear standards, so a Big Bang will instantly begin.

Exceedingly rapid expansion will occur because there will be no net gravitational force to oppose it. There will, however, be nearly simultaneous formation of local regions of predominately M matter or predominately U unmatter, since the two kinds of matter will attract like matter but repel unlike matter. Inhomogeneity will thus appear almost simultaneously with the initial Big Bang. As this inhomogeneity increases, larger and larger regions will consist exclusively of M matter or U unmatter.

Within any such region, gravity will function as expected in earlier theory. This will allow the formation of the observed stars, galaxies, and the larger structures of the universe. Looking only at M matter, it will seem that there are large voids within the universe. In this model, the U unmatter stars, galaxies, and larger structures form and reside in these M voids.

Over time, the M and U regions will each tend to consolidate, but the overall UM universe will expand, and indeed, expand at an increasing rate.

Quantum Gravity

Return now to the Planck scale, and consider what would happen if a particle of M matter were to appear at a given Planck scale location just as that location happened to produce a UM pair in accordance with its prerogatives under quantum mechanics. Since that location could presumably tolerate only one M particle, the M part of the generated UM pair would be forced to move to one side. This would have the effect of producing an MU pair in motion away from the classical M particle.

Such MU gravitons would stream randomly away from the originating M particle, which could continue to produce them indefinitely since they have zero net mass, energy, and momentum. When the MU ripple encounters another mass, suppose that the "struck" mass behaves in a laser-like manner, producing an M particle which moves along the path of the original MU ripple, and a U unparticle which moves precisely backwards from the direction of the original MU ripple. As in a laser, the original MU ripple continues along its original path.

The result is that the struck particle must recoil toward the originating M particle if the struck particle is M matter, but away from the originating M particle if the struck particle is U unmatter. That is, M matter will attract M matter, but repel U unmatter. Symmetrically, by emitting UM ripples, U unmatter will attract U unmatter but repel M matter. Interestingly, this is consistent with the classical Newtonian formula for gravitational force, including even the direction of the force.

Internal structure of the gravitons: neutrinos?

In this model, gravitons have an M component and a U component, with an overall zero net energy, mass, and momentum. Among currently known particles, neutrinos have properties which seem appropriate for these components: very small mass, energy, and momentum, combined with little further interaction once produced separately at the distant mass in the laser-like interaction. That is, we further speculate that a graviton is a pair of neutrinos, one M neutrino and one U unneutrino. It is not clear to either of us which of the currently known neutrinos (six, including the anti-neutrinos) best fits the model.

Intuitive tests

According to this model, gravitons will be very small in terms of the momentum change they cause, and they will cause no net energy change at all. This is consistent with observation and existing gravitational laws: even with light photons, there is no observable quantized interaction -- the curvature seems to be continuous, which can only result from a very small quantum effect. Further, it is consistent with the Newtonian model that gravitational effects on a distant body trade potential for kinetic energy in that body, but do not change the total energy of that body. It also resolves the question of local conservation of momentum at the distant body.

It explains why even the very early universe had inhomogeneity, and why that inhomogeneity has now become highly pronounced. It is consistent with what the authors understand of the expansion of the universe.

Physical tests: an optical telescope

According to this model, there should be U unphotons streaming from U regions into M regions. These should be observable with carefully built sensors. In particular, the sensors must be able to detect a negative energy photon. This will probably mean sensors with a large population of elevated energy state particles, and the ability to detect their transition to lower energy states. This is precisely the opposite of normal photon sensing equipment, of course.

It seems likely to us that the easiest way to run such a test would be with a differentially shielded sensor. In the first version, surround the sensor described above with material having a large population of excited state particles (i.e., additional sensor material in the charged state). In the second version, use the same array but with the surrounding material left in the ground state. If the inner material shows detectably less decay to the ground state, we would infer that incoming U unphotons are being absorbed by the charged outer material. Selection of the excited state level should be based on the energy of U unphotons expected from distant galaxies: optical energies are one obvious choice.

In July 2005, we developed an idea which may allow assembly of a U optical unphoton sensor using readily available equipment. If that is successful, a U unphoton telescope should also be practical. Images of U unmatter galaxies in otherwise seemingly void locations would be, to say the least, dramatic. We will describe this idea separately, as it involves aspects which we think are patentable.

Physical tests: radio-telescope

For the same reasons, cancellation should also occur at radio-telescope frequencies. In this case, individual stars and galaxies are usually not resolvable, but patterns should be. In particular, large volumes should appear empty, or more precisely, empty of M matter.

This is, we note happily, precisely what has been found by personnel at the University of Minnesota, who have described a void almost one billion light-years across.

If a radio-telescope with high spatial resolution were aimed at this "void", we would expect the resulting images to contain small, spatially and time-stable depressions of the background at energies corresponding to emissions of ordinary galaxies. If present, we would argue these to represent locations where emissions of U unphotons have cancelled the normal M photon background. This data may be sitting in storage already, and we hope some hard-working radio-astronomer will go look.

Michaelson/Morley

Also according to this model, gravity is a ripple in space-time. It should therefore be possible, at least in principle, to perform a gravitational Michaelson/Morley experiment. The model would seem to predict a result different from the optical version.

Gravitational mass vs. inertial mass

This model supposes that gravitational effects occur on the Planck scale. This means that there should exist something like self-gravity, where a particle experiences interaction with an MU ripple it caused at some earlier time, the scale factor being about 10^(20) between Planck scale and the wavelengths characteristic of even nucleons.

Self-gravity, however, is equivalent to inertia: it will cause the particle to remain in a fixed location, or if in motion, continue that motion in accordance with a pure translation of coordinates. Consider an analogy: suppose an unusually standoffish physicist regarded the planet Earth as a single particle (the "earthon", a very massive M particle indeed), and demanded an explanation of its very high inertia. You could explain matters to him by noting the self-gravity of the earthon, allowing the cumulative properties of the 10^(-15) meter scale nucleons to function as a single particle some 10^(20) larger. Earthon scale is to nucleon scale as nucleon scale is to Planck scale, at least close enough for analogy work.

Relativistic effects

Suppose that the original M particle is moving at relativistic velocity with respect to some space-time coordinate system. The self-gravity described above must then be modified to account for the chance that the originating particle will interact much more highly with MU gravitons moving in its direction than with those moving the opposite direction. We expect that this probability change has the form of the observed apparent mass increase.

About the authors

The authors are both graduates of Cornell University's College of Engineering: Robert in Engineering Physics (1966), and Scott in Electrical and Computer Engineering (2001). Robert is Scott's father. Robert first became interested in these issues when he attended a guest lecture at Cornell by Richard Feynman, who was then at Cal Tech, but who had earlier taught at Cornell.

When Scott was attending Simsbury High School in Connecticut, he bumped his head on a window when the school bus he was riding turned sharply. This prompted a discussion between the authors about inertia and gravity, during which Scott remarked, "oh -- like a laser" when Robert described gravitational interactions using graviton models as outlined by Feynman.

It took Robert about ten years to convert that mechanism to the present model, including an initial dead-end variant which (incorrectly and unrecognized) predicted that long rods should be gravity lasers. The ideas for radio-telescope observation also came from Scott, this time in the summer of 2006 when he visited the Green Bank radio-telescope facility in West Virginia.