British physicist Dr Mike McCulloch, who previously used quantised inertia to explain how the controversial electromagnetic space propulsion technology EmDrive works, says that he has new evidence showing his theory can also explain galaxy rotation, which is one of physics' biggest mysteries.

McCulloch, a lecturer in geomatics at Plymouth University's school of marine science and engineering, says he now has even more evidence that his "new physics theory" about quantised inertia works, and that it makes it possible to explain why galaxies are not ripped apart without using theory of dark matter.

How the EmDrive works The EmDrive is the invention of British scientist Roger Shawyer who, in 1999, proposed that – based on the theory of special relativity – electricity converted into microwaves and fired within a truncated cone-shaped closed metal cavity causes microwave particles to exert more force on the flat surface at the large end of the cone. There is less combined particle momentum at the narrow end due to a reduction in group particle velocity, so this thereby generates thrust. His critics say that – according to the law of conservation of momentum – his theory cannot work as, in order for a thruster to gain momentum in one direction, a propellant must be expelled in the opposite direction – and the EmDrive is a closed system. However, Shawyer says that, following fundamental physics involving the theory of special relativity, the EmDrive does in fact preserve the law of conservation of momentum and energy. For an in-depth explanation, see What is the EmDrive and why should I care? Why advertise with us

One of the biggest problems in physics today is how galaxies rotate. Galaxies are collections of millions of stars swirling around, and galaxies spin so rapidly that their centrifugal force should cause them fly apart, as there isn't enough visible matter in them to hold them together by the force of gravity.

To try explain how galaxies are held together, astronomers use the popular theory of dark matter, which was discovered by Fritz Zwicky in 1933 and then popularised by Vera Rubin in the 1970s.

Galaxies and how dark matter works

The theory is that galaxies contain dark matter and that this makes them gravitationally stable in the standard model of physics. McCulloch is sceptical about dark matter and he says that it is an implausible theory to explain dwarf galaxies, which are super-tiny galaxies containing only between 1,000-10,000 stars that revolve around the milky way.

There are 20 dwarf galaxies in existence from Segue-1 (the smallest) to Canes Venatici-1 (the largest), and dark matter is only meant to work by spreading out across a wide distance, but it is still used to explain dwarf galaxies, even though this requires dark matter to be concentrated within these systems, which is implausible.

Instead, McCulloch asserts that quantised inertia can be used to explain how galaxies rotate without using dark matter, and he has written a paper that has been accepted by the bi-monthly peer reviewed journal Astrophysics and Space Science.

"The photons in the EmDrive, when they go into the narrow bit of the EmDrive, fewer Unruh wavelengths fit into that narrow bit, so they lose inertial mass, and that's what I'm saying causes the EmDrive to move," he told IBTimes UK.

"In the galaxy, as you go out to the edge, the acceleration of the stars reduces, and that means the Unruh wavelengths get longer. Just like for the EmDrive, few of them fit into the cosmos so their inertial mass decreases in the same way. This is further evidence that this theory is correct, as it seems to explain both the EmDrive and galaxy rotation."

To prove that quantised inertia exists in dwarf galaxies, McCulloch came up with an equation and used it to analyse data compiled by the Panoramic Survey Telescope Rapid Response System (Pan-STARRS), which is an international collaboration of astronomers hunting for dwarf galaxies.

Using quantised inertia to explain dwarf galaxies

The formula v = (2GMc<sup>2/Θ) <sup>¼ states that the velocity of the stars in the cluster (v) is given by gravitational constant (G), times the visible mass (M), times the speed of light squared (c2), divided by the cosmic diameter (Θ).

"As you look out into the sky, you see stars moving away from you all the time because the universe is expanding and at a certain distance away, they're moving away so far that they're going faster than the speed of light, and then you can't see them anymore. This is the cosmic horizon. The cosmic diameter is the distance across the cosmos from side to side," explained McCulloch.

"The great thing about this formula for quantised inertia is that you don't have to add anything you can't observe. The formula has no adjustability. There is only one possible prediction and it fits the data, whereas you can't see dark matter."

McCulloch's paper, entitled "Low-acceleration dwarf galaxies as tests of quantised inertia", will be published by Astrophysics and Space Science in March, but it is available to read online now in its entirety on ResearchGate.

"There's lots of evidence for quantised inertia on a huge range of scales, be it the EmDrive, fly-by anomalies, dwarf galaxies, galaxies and galaxy clusters, and the cosmic acceleration. I believe all this evidence is pointing towards new physics, that works by extracting energy in a new way from the zero-point field using horizons," he said.

Life since the EmDrive paper

The "new physics" theory of quantised inertia McCulloch made waves online in April 2016 when he published a paper on a "new physics theory" called quantised inertia, which he first proposed in a 2007 paper. The theory violates Einstein's Equivalence principle by stating that there is a new acceleration extracted from the zero-point field by horizons, and that if inertia were to be quantised, this would explain the anomalous thrust produced by the EmDrive. His paper shows that when his theory is applied to all the experiments so far conducted on the EmDrive, the order of magnitude of thrust seen in all the experiments matched predicted results generated by applying the theory to the data, as well as 28 other anomalies. He asserts that light particles contain inertial mass, and the EmDrive works because of a new force extracted from the zero-point field by horizons which damp waves of Unruh radiation.

McCulloch says that after international media covered his paper in April 2016, he received a huge amount of abuse online from people who don't believe the EmDrive works, but he also now receives fan mail from other physicists and EmDrive enthusiasts, which he really appreciates.

"Some of the things people have said about me have been incredible. You'd think I was committing a crime. But now my predictions about the EmDrive are far better than before because I realised that some of the experiments used dielectrics, which reduce the speed of light in the cavity, and when I included that, my predictions actually improved," he said.

"There's a famous saying coined by the Royal Society, 'Nullius in Verba'. It means that words mean nothing, the data is the important thing. If you're doing science, you have to be willing to put up with critics. The important thing is focusing on the data, and sometimes you need to ignore what the group is saying."

McCulloch is now seeking to organise the first EmDrive-specific conference in Plymouth, but he says he would only feature presentations from people who are willing to share all of their theories and methodology, and they must have the data to back up their theories.