Is There Only Spacetime? (part 1)

In a recent post, I mentioned in passing that “the close relationship between energy, gravity, and inertia is still a mystery, despite apparent confirmation of the Higgs boson.” But wow, I may have just stumbled on an outsider theory that can resolve that whole mystery, and more. It’s from a laser specialist and entrepreneur named John A. Macken, and his work can be found at onlyspacetime.com.

Where Macken begins is with the idea that “mass” is just energy confined to a particular frame of reference. This sounds like it might be just an obvious truism based on special relativity, but once one looks at the details, it covers more ground than you might think.

His start on this came, naturally enough, when thinking about lasers. The light inside a laser has energy, which means it has an equivalent mass, which means it has inertia. Now inertia seems very mysterious as a property for particles, but for light, he realized, there’s nothing mysterious about it.

If you accelerate a laser, the light hitting the back mirror — the one accelerating toward it — reflects away with more energy than it arrived with. This gives it a shorter wavelength. Conversely, when hitting the front mirror, accelerating away, it loses energy. This means it also gains and loses momentum, which for light is linearly proportional to energy. The change of momentum produces a net force on the rear mirror... which exactly accounts for the resistance to acceleration that such an amount of mass/energy should have.

I suppose you could say that inertia is momentum confined to a particular frame of reference. In Macken’s view, as in Einstein’s, energy and momentum are the two fundamental “real” properties, underlying everything else.

The gain in energy for the blue-shifted forward light exceeds the loss for the red-shifted backward light. The difference accounts for the kinetic energy of an equivalent mass. Or rather, it accounts for the increase in total energy (kinetic energy being a secondary property derived by subtracting the total energy in one scenario from that in another).

Gravity deflects light when applied sideways, and gives it a red or blue shift when applied lengthwise. Either way, it turns out that the light in the laser has the correct weight, explained entirely by the momenta of the photons: it either pushes on the downward mirror harder than on the upward one, or if going sideways, the mirrors have to be angled up a hair, volleying the photons in arcs like tennis balls, thereby experiencing a net downward force at each end. (Real lasers incorporate a slight curvature in the outer parts of their mirrors to corral stray photons back into alignment.)

There’s more. Particles with rest mass also have a wavelength, which depends on their momentum relative to the observer. This de Broglie wavelength, as it is known, happens to match the wavelength of the interference pattern produced between the red- and blue-shifted light in the accelerating laser, as viewed from outside. And it foreshortens correctly at relativistic speed.

According to Macken, this all generalizes correctly to any contained bunch of light — for instance, a box of arbitrary shape with warm sides, full of blackbody radiation. I haven’t been able to check his math on all this, but I probably could if I spent enough time on it.

Put it all together, and Macken realized that if you imagine a “particle” as actually being energy without rest mass, moving at lightspeed but confined to a particular frame of reference, you have a clear explanation for most of the properties we associate with rest mass, without needing to resort to any Higgs field. Furthermore, this approach correctly states the magnitudes of inertia and weight and so on, whereas the Higgs theory leaves you needing a new arbitrary constant.

In what sense is this energy and momentum confined? Obviously not along a single axis, as in a laser. But not in a directionally uniform way either, as in a warm box. Most fundamental particles have a spin property. They appear to have angular momentum — a property which is difficult to imagine applying to anything genuinely pointlike. For the common cases (i.e. the fermions), this confined energy must be moving in a circle. But the nature of whatever energy it might be that is moving in a circle is still entirely hypothetical.

At this point, Macken started hunting around for ideas about what this confined energy might consist of, which could explain the properties of matter without requiring additional arbitrary assumptions. So far we’ve stuck with ideas that would have been well understood in the time of Einstein, but now we move beyond the realm of known physics. He eventually found a hypothesis which can apparently do the job, in a form of a spacetime wave which is similar to, but perhaps distinct from, gravity waves. These waves consist of spacetime strain, which locally affects the volume of space and the rate of time, in an oscillation which propagates at lightspeed. Gravity waves (unlike gravity fields) are supposed to always average out to zero net change of space or time, but Macken’s hypothetical waves do have the ability to produce unbalanced net effects. And yes, as the astute among you may be guessing at this point, this means that he’s going to try to account not just for how mass responds to gravity, but for how it can produce gravity.

To back up for a moment, why would this energy travel in a tiny circle? Here he brings in analogy from superfluidics: the quantum vortex. In superfluids such as liquid helium, apparently, it’s impossible to stir a vat of the stuff so that the fluid as a whole is rotating, unless the container is ring-shaped. What happens is that all the rotation concentrates itself into tiny nuggets of spin, with the surrounding fluid being stationary. These vortices shrink until they reach a minimum size, which for helium is a fraction of a nanometer — tiny enough that only a few atoms are involved. Each vortex has a tiny open void at the center, about the size of a single atom. All net angular momentum of the fluid is in these vortices, and the amount of angular momentum carried by each is restricted to particular quantized magnitudes. Macken speculates that maybe the angular momentum of particles is quantized because the vortex is unstable except at frequencies where the tendency to radiate energy outward creates a cancelling interference pattern.

He postulates that to his hypothetical strain waves, spacetime is a perfect superfluid, and if any net angular momentum exists in the energy carried by these strain waves, it will immediately concentrate itself into quantum vortices, of a size much tinier than the nanometer scale. The waves which carry the energy and momentum are Planck scale — the smallest that anything can be — but the vortices are much larger, comparable to the size of an atomic nucleus. (A helium nucleus has about 1/10000 the diameter of the whole atom. This is large enough that he has to devote some time to the question of why electrons appear pointlike in collision experiments; the explanation he comes up with may help clarify the reason for the uncertainty principle.) His hypothesis is that a particle such as an electron is, at bottom, a quantum vortex in superfluid spacetime. He has a new term for this kind of vortex: he calls it a rotar. Note that this means that his strain waves are not confined only to the vortices: they are present in nonrotating form throughout spacetime, where they constitute zero-point energy, and contribute the pressure which keeps the rotar confined.

What particle is constituted by a given rotar is determined by its total energy and its angular momentum. Heavy vortices are smaller than light ones (to be specific, mass times radius is the constant ħ∕c).

When the wave pattern moves in a circle, it’s as if there were a rotating dipole at the center, like a bar magnet with positive strain at one end and negative at the other. The magnitude of oscillating spacetime strain associated with a single particle is very small: he compares it to changing the diameter of Jupiter’s orbit by the width of a hydrogen atom, or the age of the universe by twenty microseconds. And the permanent net strain which produces gravity is that much smaller again, proportional to the square of that tiny number. This is why it takes a septillion octillion rotars to produce the amount of gravity we’re accustomed to.

With much greater difficulty, he’s somehow also worked out a rotar-based theory of electromagnetics. I haven’t begun to study this part yet. I’m particularly curious to see how he explains photons. With this in place, he feels ready to proclaim his motto, which is also the title of his freely downloadable book: The Universe Is Only Spacetime. He asserts this because he thinks that spacetime waves can explain all energy and all matter, with no need to hypothesize anything else.

I don’t have any idea how thoroughly this theory covers the less obvious challenges, let alone how scientifically valid the whole mess is. The weak-force bosons, for instance, are not rotars in the way that fermions are.  I’m not sure he’s finished working through that area. And I don’t think he’s yet gotten anywhere near what would be the holy grail for a new insight into quantum mechanics: a mathematical rule that explains why we have particles of the particular masses and charges that we observe, which seem to have been assigned completely arbitrary values.

To review what we’ve got so far, in order from most verifiable from most speculative, he is proposing:

1. energy and momentum without rest mass, if confined, will exhibit inertia and weight and kinetic energy in the same way that solid mass does, and on the particle scale, will show the same wavelike duality that we see experimentally
2. a hypothetical new kind of Planck-scale spacetime strain wave, rotating in a quantum vortex (or rotar), could contain energy and momentum in this way, appearing from the outside as a particle with mass and spin
3. with a tweak to the math of this wave (which he based on the Kerr effect in optics) such that the effect on spacetime involves a component proportional to the square of the strain (miniscule but always positive) in addition to the first-power component of strain oscillation (which sums to zero), the net total strain around a rotar would also give it a gravitational field
4. with more effort (which I haven’t looked at enough yet to even summarize), there may be a way to also explain electromagnetic force as a side effect of spacetime strain
5. and so on, with luck, to explain the gluon color force, the weak force, and whatever it is that they found when looking for the Higgs boson... at which point you have a Theory of Everything.

So he’s trying to add a new kind of spacetime wave to physics. Is there anything he wants to take away? Yes. He does not believe that the electromagnetic force is carried by “virtual photons”, for instance, and he does not believe in a Higgs field. What his position is on virtual gauge bosons (W and Z for weak force, and gluons for strong force), or on what the Higgs boson really is, I don’t know yet.

One point to note is that in a proton or similar quark-based composite particle, most of the mass comes from the binding energy between the quarks, not from the quarks themselves. Conventional quantum mechanics would say that this binding energy exists in the virtual particles carrying the attractive force, but Macken stores the binding energy inside the rotars, saying the attractive force compresses them to a tighter radius and therefore a higher energy.

The math looks fairly sound so far, and there is a hell of a lot that’s attractive about this theory. Now that he brings it up, there are obvious common-sense problems with the idea that a virtual photon can convey an attractive force (it would have to go backward in time, or have negative energy), or that a pointlike elementary particle can have angular momentum (a conundrum which has led some mainstream physicists to describe the electric field around a particle as rotating). It sure is nice to see properties such as inertia and weight as obvious and natural instead of obscure and arbitrary. And it would be a big breakthrough if we could explain gravity as a side effect of a quantum property. But on the other hand, to make up a completely new kind of spacetime wave, and then to hide it under the rug by asserting that it only exists at the Planck scale so it can never be detected, is a lot to ask. And as my dad (who has a physics degree) said when I described this to him, and described the nonlinear aspect of spacetime oscillation which is supposed to produce gravity as a residual side effect, “Oh, you can make anything out of a nonlinearity.” I also worry that his widespread use of Planck units, which make differing dimensions appear commensurable, could be covering up a fast one here or there.

The cool part is, it’s perfectly possible for this theory to be partly true, and that it might be a helpful contribution even if he’s lost his way in the further reaches of it. We might find a useful bit of progress in the idea of the rotar (which explains inertia and spin and so on for fermions) even if the bit about nonlinear spacetime strain turns out to be nothing but inflated guesswork, or the true nature of bosons has nothing to do with rotars. Maybe we do still need a Higgs field for W and Z bosons to have mass; that wouldn’t invalidate the idea that said mass is just some form of confined lightspeed energy.

I think I’ll be posting more about this as I study it further.

What I really wish I could read is a critique of this approach by a qualified physicist. As far as I have been able to find, no such critique exists; the theory is pretty new, and so far is apparently being ignored by the scientific establishment, though it passes all the basic tests that would screen out 99.9% of pointless crank theories, mainly by just having solid math.