Yesterday, a few people online kindly sent me the news that a galaxy called Dragonfly 44 has been found apparently containing 99.99% of the so-called 'dark matter' (see reference). Many, for example Sean Carroll, said that this supports the dark matter hypothesis. However, in reality it worsens the outlook for dark matter, which has to be added in different ad hoc amounts to each galaxy, in huge amounts to this one, and so it further supports MiHsC (quantised inertia) which works for all galaxies without any arbitrary tuning needed...
For each separate galaxy they find, the darkmatterists have to add dark matter in different amounts, 90% for the Milky Way, 99% for dwarf satellite galaxies, 99.99% for this one. This number is arbitrary, they chose it incestuously to make general relativity work for the data, and it has no reason behind it except to save GR. That means that the dark matter hypothesis is not only not falsifiable (you can look for dark matter for ever), it is also not predictive. Given the visible light distribution, dark matter cannot predict the velocity of stars. So dark matter is a bit like Peeves at Hogwarts: useless, but you can't get rid of him.
In contrast MoND and quantised inertia / MiHsC are both predictive. Given the visible mass M (it's best to base theories on visible stuff) MoND says the stellar velocity is v=(GMa0)^1/4 (a0 is a fitting parameter) and MiHsC says v=(2GMc^2/Hubblescale)^1/4 (no fitting parameter, and a slighly higher velocity, see equation below) and both predict the velocity dispersion of Dragonfly 44 within the uncertainty and without the need for any dark matter.
The important advantage of MiHsC over MoND is that MiHsC has no adjustability, at all! MoND was an inspiration for me, but it is not a theory, it is an empirical formula that happens to fit galaxy rotation if you 'tune' the adjustable parameter a0 against the data, so it is not surprising that it fits the data, because it has been fitted to it. The parameter a0 has no 'physical reason'. MoND is a bit like an engineering formula with its tune-able a0. In contrast MiHsC has been derived from first principles, says the velocity has to be one value with no tuning possible, and every parameter in the MiHsC formula below is known from observation and is there for a good physical reason, so it is remarkable that it works on all galaxies including Dragonfly 44:
In this way MiHsC resembles special relativity in that there is no arbitrariness about it, no input numbers, but it will need input from better mathematicians than me to properly describe higher order effects due to the interaction of Unruh waves with relativistic horizons or cavities.
The important advantage of MiHsC over MoND is that MiHsC has no adjustability, at all! MoND was an inspiration for me, but it is not a theory, it is an empirical formula that happens to fit galaxy rotation if you 'tune' the adjustable parameter a0 against the data, so it is not surprising that it fits the data, because it has been fitted to it. The parameter a0 has no 'physical reason'. MoND is a bit like an engineering formula with its tune-able a0. In contrast MiHsC has been derived from first principles, says the velocity has to be one value with no tuning possible, and every parameter in the MiHsC formula below is known from observation and is there for a good physical reason, so it is remarkable that it works on all galaxies including Dragonfly 44:
In this way MiHsC resembles special relativity in that there is no arbitrariness about it, no input numbers, but it will need input from better mathematicians than me to properly describe higher order effects due to the interaction of Unruh waves with relativistic horizons or cavities.
A loose analogy to this crisis in astrophysics would be holding a competition to see who can make a shoe to fit a foot they've only seen from a distance (like a theory that must predict galaxy rotation from observed quantities to be useful). Shoemaker 1 comes with his shoe, says 'It fits', but you see nothing. 'It's invisible!' he says (GR and dark matter). Shoemaker 2 comes with a shoe that has an adjustable strap and he adjusts the strap to fit it (MoND). This is better. Then shoemaker 3 comes with one unadjustable shoe, and it fits (MiHsC). Obviously, the third shoemaker is the best one.
I cannot emphasise enough the difference between tunable theories like dark matter, and to a lesser extent MoND, and a non-tunable theory like MiHsC. Only a non-tunable theory gives a real understanding of the physics.
I cannot emphasise enough the difference between tunable theories like dark matter, and to a lesser extent MoND, and a non-tunable theory like MiHsC. Only a non-tunable theory gives a real understanding of the physics.
References
van Dokkum, P., 2016. A High Stellar Velocity Dispersion and ~100 Globular Clusters for the Ultra Diffuse Galaxy Dragonfly 44. http://arxiv.org/abs/1606.06291
McCulloch, M.E., 2012. Testing quantised inertia on galactic scales. Astrophys. & Sp.Sci., 342 (2), 575-578. http://arxiv.org/abs/1207.7007