Dark matter contradicts itself.

There has just been a study published in Science (Harvey et al., 2015) that is interesting because it shows the dark matter hypothesis is starting to contradict itself.

Harvey et al. have looked at the light from familiar objects like galaxies as seen from behind galaxy clusters, and looked at the distortion in the images due to gravitational lensing. They know what a typical galaxy looks like: a disc, so if it looks like a U-bend instead when it's behind the galaxy cluster, then they can infer the bending of the light that must be occurring and assume this bending is due to dark (invisible) matter in the cluster. They looked at 72 galaxy cluster collisions, and have modeled the collisions using several kinds of dark matter, and have shown that the only kind of dark matter that fits the observations, is a kind that doesn't interact with itself. I'd like to point out here that this makes the dark matter hypothesis self-contradictory since the dark matter particles have to be given a lot of kinetic energy (momentum) so that inertial/centrifugal forces keep them spread out in their usual orbital halo, but if you now imagine that two clouds of dark matter hit each other there should be a 'push' as the particles collide. This study proves there isn't any such push, so the simplest solution is that there is no dark matter. I'm sure someone will think of a way to make dark matter more complex to save the hypothesis, but it gets ever more ridiculous.

In contrast, MiHsC says that there is no dark matter (see my blog here and my paper here) and that the light is bending because its inertial mass varies due to the variation in acceleration within the cluster. I know the inertial mass of light is a controversial issue, but it has never been well understood, and MiHsC predicts galaxy rotation, cosmic acceleration, the flyby anomalies, the emdrive (light in a box) and many other anomalies quite well without invisible entities or contradictions (Introduction to MiHsC).

(Thanks sincerely to those whose online comments helped correct a technical error about dark matter that I made in an earlier version of this entry, but my original argument still stands).

References

Harvey D, Massey R, Kitching T, Taylor A, Tittley E. The non-gravitational interactions of dark matter in colliding galaxy clusters. Science 27 March 2015. Read more at Phys Org.

McCulloch, M.E., 2012 Testing quantised inertia on galactic scales. Astrophysics & Space Sci., 342, 575-578. Preprint. Journal.

One-wave MiHsC and the EmDrive

MiHsC (see an introduction) assumes that inertia is caused by a radiation pressure from Unruh radiation, and that the waves of this radiation are only allowed to exist if they have nodes at information horizons like the Rindler (local) or Hubble (cosmic) horizon, because if they didn't have nodes there, we could infer what lies behind the horizon and it wouldn't be a horizon (logic/information affects local physics).

So far with MiHsC I've used an approximation, and assumed that as accelerations decrease, then the number of waves in the Unruh spectrum decreases linearly as they are disallowed by the horizon, and so the inertial mass decreases in a new way (predicting galaxy rotation without dark matter...etc). I can get away with this because the accelerations are rarely small enough that only one or two Unruh waves fit.

To apply MiHsC to the resonating emdrive (a truncated metal cone), and probably to very low cosmic accelerations too, I need to consider individual Unruh waves. So I have recently tried an alternative approximation of MiHsC that assumes that there is only one wave at the peak of the Unruh radiation spectrum and this wave either fits or doesn't within the horizon (which for the emdrive, is its walls). This leads to a prediction for the anomalous force on the emdrive (F) like this

F = -PQ/c * (|sin(pi*w_small/L)|-|sin(pi*w_big/L)|)

where P is the input power, Q is the quality factor, c is the speed of light, w_big and w_small are the diameters of the big and small end plates of the emdrive, and L is its length. As you can see I'm using the magnitude of a sin function to decide whether the Unruh wave (only one now) fits within the walls or not, at the wide end and the narrow end. This Table shows how the results differ from what I had before:

Experiment       Observed      MiHsC2d    OnewaveMiHsC
                                     ----  milliNewtons ----
----------------------------------------------------------------------
Shawyer 1             16               4.1              7.7
Shawyer 2           147           148.9            54.7
Cannae drive           9               5.3              4.3
Juan et al. A         214           154               39
Juan et al. B         315            241              61
NASA B1                 0.09          0.26            0.07
NASA B2                 0.05          0.63            0.18
NASA B3                 0.06          0.12            0.03
NASA vacuum        0.03          0.70            0.20

As you can see, I've used the 2d (two-dimensional) version of spectrum-MiHsC to compare with the 2d one-wave MiHsC, for a fair comparison. I've shown the Cannae and Juan (2012) cases in red because I'm not confident I have the right geometry for them. MiHsC predicts that (usually) photons are more likely to see a resonating Unruh wave at the wide end, so the photons' inertia increases as they go towards the wide end and to conserve momentum the whole cone then has to move the other way. As you can see, the new formulation is much better for the NASA data but worse for the more powerful of the Shawyer experiments (I still don't know the uncertainties in the data).

Interestingly, this approach predicts there can be a reverse mode for the emdrive (not a particularly bold prediction I admit since NASA may have seen a reverse already). MiHsC predicts this reverse occurs if you 'tune' the Unruh waves to fit better into the narrow end.

I've been trying to develop a one-wave version of MiHsC for application to cosmology for ages, the emdrive is useful (if real) because it provides data on which to test progress.

My earlier blogs on the Emdrive can be accessed here.

Predicting Proxima Centauri's Orbit

The best way to persuade others to accept a new paradigm is to find an anomaly that embarrasses the old one. The galaxy rotation problem should be such a thing, but the old theory has been propped-up by dark matter which is flexible enough to fudge a solution.

The goal then is to find an anomaly which dark matter cannot fudge. Its Achilles' heel is scale, since, to work for full-sized galaxies, dark matter must have a tendency to spread out smoothly to explain why it stays out in the galactic halo, so dark matter shouldn't effect dynamics on smaller scales. One possible test then is to use globular clusters, smaller bound collections of stars within galaxies. They do indeed show a very similar rotational anomaly (Scarpa et al., 2006) but they are not simple enough to provide a clean test. Smaller and simpler are wide binary stars and again, a similar, orbital, anomaly has been seen (Hernandez et al., 2011) but the data is still too noisy. Recently, I've become interested in a wide 'trinary' for which the data is a bit better: our closest neighbour: the Alpha Centauri system.

I've talked about this before: this triple star system is interesting because the first two stars orbit close together so their masses are well determined from their orbits, but the third star orbits far from them in a low acceleration regime where MiHsC should apply. Sure enough, there is an anomaly. The third star, Proxima, has an orbit that is so fast that it should spin off into deep space with the centrifugal force, since the known mass of the the other two stars is too small to gravitationally bind it. Yet, other data, for example the similar chemistry of the three stars and the fact that they all seem to move together in the sky suggest that Proxima is bound to the system, but according to Newton, it can't be with that fast orbit.

This makes a nice experiment because the mass of the central two stars can't be increased to bind Proxima (their masses are too well known) and dark matter can't be used either (too small a scale). MoND (Modified Newtonian Dynamics) can be applied here, and can be thought of either as an increase in the gravitational constant, or a decrease in the inertial mass, but MoND has no physical model (no reason) behind it and it needs an adjustable parameter called a0 to be set by hand, again with no apparent reason.

MiHsC can also be used to predict the orbit, and it has a clear reason, and no adjustable parameters are needed. It predicts that the low acceleration of Proxima reduces its inertial mass so it can more easily be bent into a bound orbit by the small observed mass of the central two stars. The observed orbital velocity of Proxima and the various predictions of it are as follows:

Observed = 0.53 +/- 0.14 km/s   (to be improved by new ESA GAIA data)

Newton    = 0.34 +/- 0.02 km/s   (no wriggle room)
MoND      = 0.42 +/- 0.2 km/s    (if a0 is set to 1.2*10^-10 m/s^2)
MiHsC     = 0.65 +/- 0.02 km/s   (no wriggle room)

Newton and Einstein disagree with the data (unless the assumed orbit is extreme, which it could be) and dark matter can't be applied to this case. Both MoND and MiHsC agree with the data, and so they reconcile the chemical, co-moving and orbital data, but MiHsC does it with a reason and without the need for an adjustable parameter. I have just submitted a paper on this, so a reviewer somewhere is having fun.

References

Hernandez, X., M.A. Jimenez and C. Allen, 2011. Wide binaries as a critical test of classical gravity. Euro. Phys. J. C., 72, 1884. Preprint.

Scarpa, R., G. Marconi, R. Gilmozzi, 2006. Globular clusters as a test for gravity in the weak acceleration regime. Proceedings of the 1st crisis in cosmology conference. Am. Inst. Phys Proceedings series, Vol. 822. Preprint.