An Introduction to MiHsC / quantised inertia

The idea of inertia is that in a vacuum, where there is no friction, objects move along in a straight line at constant speed until you push on them. This tendency was first isolated by Galileo, who rolled balls down inclined planes (balls feel less friction). This tendency, inertia, has always been assumed but never explained.

Meanwhile physics has moved towards a study of information, and it has been realised in the past few decades that when you accelerate something, say, to the right, information from far to the left can never catch up to it, this means there is an information-boundary or 'horizon' to its left which is like a black hole event horizon (it is called a Rindler horizon). A kind of Hawking radiation comes off this horizon, which is called Unruh radiation (it was proposed by Bill Unruh) and is seen as background radiation, but is seen only by the accelerated object (there is some evidence for Unruh radiation eg: Smolyaninov, 2008).

I have suggested that the waves of Unruh radiation cause inertia as follows: the waves have to fit exactly between the rightwards-accelerating object and the Rindler horizon that forms on the left. This is similar in form to the Casimir effect, but I use logic instead: a non-fitting partial wave would allow us to infer what lies beyond the horizon, so it wouldn't be a horizon anymore. This logic disallows Unruh waves that don't fit on the left: they dissappear. As a result more Unruh radiation pressure hits the object coming from the right than from the left and this imbalance pushes it back against its acceleration, just like inertia. I have shown that this effect is the right size to provide a mechanism for inertia, and so can explain it for the first time (paper) (there's a factor of 2 error in the paper, when corrected the result is within 29% of the Planck mass). An analogy is a boat near a seawall. Seaward of it, waves of all wavelengths can exist for there is no boundary, but between it and the seawall fewer waves can fit: only those that have 'nodes' (the unmoving part of the wave) at the wall and boat. As a result more waves hit the boat from the seaward side, pushing it on average towards the seawall.

It does not end there, however, because, to be tested, a model needs to predict something unexpected, and this model for inertia does. There is also a horizon much further away, at the Hubble horizon, so even to the right of the object some of the Unruh waves are disallowed, especially the very long Unruh waves that you get if the object has a very low acceleration. The new prediction then is that objects with very low acceleration lose inertial mass in a new way. This model for inertia can be called: Modified inertia by a Hubble-scale Casimir effect (MiHsC) or quantised inertia.

In this way, MiHsC solves a problem astronomers have had with galaxies. They are spinning so fast that they should centrifugally explode. Oddly, they don’t explode, so astronomers have had to invent invisible ‘dark’ matter and add it to the galaxies to hold them together with extra gravitational pull. This is a ‘patch’ since it is not predictive: you have to add dark matter 'by hand' to get agreement between standard gravity and the observed spin of the galaxy. Interestingly, the stars at the galaxy’s edge (the ones misbehaving) have low accelerations, so see very long Unruh waves, and MiHsC predicts a loss of inertial mass for them, that reduces the centrifugal outward force on them by just the right amount to make everything fit, see here and here. MiHsC then is an alternative explanation of why galaxies do not break up with the centrifugal forces, and is better than the dark matter hypothesis and MoND because there is only one way to apply MiHsC, and that way works (McCulloch, 2012).

MiHsC also explains other observed anomalies, for example: the recently-observed cosmic acceleration, the low-l cosmic microwave background anomaly (a suppression of patterns at the Hubble scale), the controversial lab experiments of Podkletnov (1992) and Tajmar (2009), the flyby anomaly, the emdrive, and others.. Here is a summary of all these tests.

MiHsC is not fully developed yet, and to do this I need to persuade it to show itself in a controllable and repeatable lab experiment (in progress) but, if confirmed, there are applications. MiHsC predicts that when you suddenly accelerate something (eg: spin a disc very fast) the disc, and objects nearby, should gain a bit of inertial mass and to conserve momentum they will move anomalously: a new way to move things. More generally, MiHsC predicts that whenever you put a horizon into the zero point field it creates a gradient in it that can pull on objects. MiHsC also predicts that you can’t have a constant velocity, zero acceleration, since the Unruh waves would then be longer than the Hubble scale, and none would fit, so inertia would collapse. This modifies special relativity’s insistence on a speed of light limit, and the predicted (tiny) acceleration agrees with the observed cosmic acceleration, as noted above.