I've suggested (& published in 21 journal papers) a new theory called quantised inertia (or MiHsC) that assumes that inertia is caused by relativistic horizons damping quantum fields. It predicts galaxy rotation, cosmic acceleration & the emdrive without any dark stuff or adjustment. My Plymouth University webpage is here, I've written a book called Physics from the Edge and I'm on twitter as @memcculloch

Tuesday, 8 September 2020

The Ball and the Teapot

Imagine a ball in space. Strictly speaking in physics and especially in quantised inertia you can't start talking about it being stationary or not because it has to be moving relative to some other object, so let's say it's static relative to a nearby teapot, but far enough away that the attraction from the teapot is small.

Now put a horizon on one side of it. According to quantised inertia this will damp the Unruh waves from the direction of the horizon and so the ball will be pushed by the imbalance in the Unruh radiation field towards the horizon. Another way to think about the same thing, the informational way (see reference) is that the horizon deletes the knowledge the ball has about the cosmos beyond it. Landauer's principle says that every time you delete information, say, you erase 101011 to 000000, then entropy decreases. That cannot be allowed, so the second law of thermodynamics says that high-entropy heat energy must appear to compensate. So computers get warm when you erase data. I've calculated this energy for the deletion of space, and it turns out to be just enough to power the movement of the ball predicted by quantised inertia (see ref).

So the ball accelerates towards the horizon. Now, as pointed out by several people online or in emails, what happens if suddenly the horizon disappears so the ball gets back all its knowledge about the cosmos behind it? The problem is, it still has the kinetic energy it picked up from the loss of information. Does it lose the energy when it gets the information back? The answer is not necessarily "Yes", because although the second law of thermodynamics says that 101011->000000 must release energy, there is no such imperative for 000000->101011, since there is no drop in entropy.

Can we use this asymmetry, and repeat the process to generate energy? I think that is what is happening with the cycling photons (near and horizon, then far..etc) in the emdrive. However, this brings up many fascinating new questions to ponder. Where is the information 'stored' while the horizon is close, so the system can get it back when the horizon is gone? Can information or heat be swapped between reference frames? How does this relate to the black hole information paradox?

Getting philosophical for a moment it makes sense that our new ability to model worlds ourselves (simulations, games) is inspiring new models of the one we are in, including my recent attempt to express quantised inertia using information theory. Is it just the latest useful analogy? (Probably). Is the cosmos a self-evolved bit-system? Or are we in a deliberate simulation? I'm sure the theologists will spend many a happy hour discussing that!


McCulloch, M.E., 2020. Quantised inertia, and galaxy rotation, from information theory. AdAp (accepted). Summarised in my ANPA talk here (the relevant bit starts at 16:24)

Thursday, 3 September 2020

What I said to Wired

An article has just appeared in WIRED about Woodward's theory. The author Daniel Oberhaus emailed me a couple of weeks ago asking my opinion of Woodward's work and he quotes me in the article as saying "In my opinion there is no merit to Woodward's theory". See this link for the article. This quote is a 'slight' truncation of what I said :) See his questions in bold, and my answers below:

Wired: How would you sum up your feelings about Jim's theory in a sentence or two? Is he crazy or is there merit to his ideas?

In my opinion there is no merit to Woodward's theory. It shares the problem of most of modern physics that it is constrained to work within the framework of general relativity so the derivation is complex and contrived and contains many unlikely assumptions and even some arbitrarily added factors, and yet it is still orders of magnitude away from predicting the Mach effect thrust it was intended to predict! The Mach Effect experiments are interesting but we have to consider the possibility that they are vibrational artefacts.

Wired: There's clearly a lot of skepticism around Jim's Mach effect theories. If you count yourself a skeptic, what don't you buy about this theory?

There are many theoretical problems with it, see eg Rodal 2019 and in going through the derivations you see that a lot of arbitrary factors are added in. However, my main reason for disregarding it is that it does not work. It fails to predict even the lab observations it was designed to explain - its predictions of observed thrust have been shown to be a factor of one thousand times out (eg: Mahood, 1999). I note that in the papers written about it the data is rarely compared with the observations directly.

Wired: What would it take to convince you that it was correct, if anything?

To convince me it would need a simply-derived non-arbitrary formula that predicts all the Mach Effect thrust experiments and a demonstration that the thrust varies as expected given the parameters in the theory, to rule out artefacts. So pretty much the opposite of what has happened so far.

Wired: Jim's been claiming to have produced propellantless propulsion for years. Do you think these results are real, or just noise / measurement error?

I think the experimental results are more interesting than the theory, but there is a significant possibility with vibrating solid objects that artefacts can occur (as seen with the Dean drive).

Wired: If not Mach effects, what do you think is a better explanation for what could be producing this apparent thrust? Why do you feel its a better explanation?

Vibrating objects have artefacts that can appear to be thrust. If the thrust is real then it does not seem to agree with the Woodward theory anyway. I have suggested the theory of quantised inertia (McCulloch, 2007) which predicts galaxy rotation without dark matter and predicts some, not all, of the Mach effect tests (McCulloch, 2018). 


Rodal, J.A., 2019. A Machian wave effect in conformal, scalar–tensor gravitational theory. General Relativity and Gravitation, Volume 51, Article number: 64.

Mahood, T., 1999. Propellant-less propulsion: recent experimentla results exploiting transient mass modification. AIP Conf proc. STAIF-2000. AIP, 1014-20.

McCulloch, M.E., 2007. Modelling the Pioneer anomaly as modified inertia. MNRAS, 376(1), 338-342. 
McCulloch, M.E., 2018. Propellant-less propulsion from quantised inertia. J Space Exploration, Volume: 7(3).

Sunday, 9 August 2020

Minding One's Ps and Qs

I am impressed with the six quantised inertia experiments that are going on around the world. The spirit of science and curiosity is being brilliantly represented by the people who agreed to be part of my DARPA project, and by some of those I met at conferences or on twitter. It is exciting to see the number of experiments growing every month. To recap, all you need to do is to get light to accelerate enough (bounce around, circulate) inside an asymmetric metallic setup.

However, there is a learning process due to my lack of experience in experimental design .. and telling people what to do! The aim is to prove or disprove quantised inertia in a lab test. To do that, we have to be able to make a specific enough prediction that the lab tests can detect or rule it out. With QI this is uniquely possible since, in its simplest form, the expected thrust is F=PQ/c. The power of the light used (P) is known, so is the speed of light c. What is difficult to know is the Q factor, which is crudely the number of times the light bounces around / circulates in the cavity before dissipating as heat. What thrusts the cavity in QI is not the force from the photons (F=P/c) but the metal cavity making a gradient in the Unruh radiation pushing on the cavity (F=PQ/c).

So far, in all the tests done by, for example, the lab in Dresden, we have not known the Q factor of the cavity. In Dresden this is because Tajmar could only determine that Q was "greater than 19" and also because, as a quick and dirty approach, he used a system (an open cavity) that our cavity model could not cope with. What has proved to be a better experiment is the fibre-optic loop being tested in Madrid. The great advantage of this setup is that the Q is simply the number of times the light goes around the loop - a sort of electromagnetic version of a Formula One race. Orderly & quantifiable!

From now one we need to make sure that in all experiments both Power P and Q are known. I should have listened to my mother who always used to tell me to "mind my Ps and Qs".

Saturday, 25 July 2020

Five Experiments

While I'm sat here in Devon, thinking, there are five intrepid groups actually doing experiments, so I thought I'd just briefly outline what they are doing. A lot of these experiments are reproducable so you could set up your own QI-test based on one of these, on my naive suggestion at the end (see the link), or better still - your own technique.

Madrid, University of Alcala.

This group was the first to be set up. In 2016, their leader, Prof Jose Luis Perez-Diaz came to stay in Plymouth for a year, funded by a Salvador de Madariaga grant, to liaise with me about possible QI experiments and we came up with a possible thruster design that involves a many-looped fibre-optic. Laser light cycles around it at high acceleration, and sees short Unruh waves that are damped asymmetrically either by the asymmetry of the loop itself or a metal shield on one side. A thrust should appear. For a 2W laser, QI predicted 1 microNewton of thrust. The loop was put on a pendulum and a thrust was seen of between 1-4 microN. This is on the order of 0.001 N/kW. It seems small but this is fuel-less propulsion, so it is a huge deal, allowing light rockets (both in the sense that they only use em radiation and are non-heavy) and interstellar travel. However, this Spanish result is inconclusive so far. The pendulum is subject to significant artefacts.

Dresden, TU-Dresden.

I have to be careful what I say about this one as Prof Tajmar does not wish me to give details. I persuaded Tajmar to take part in my DARPA-funded project in 2017. The idea was that if I could get even the famous 'Dr Zero' to say 'Hmm..' then the world would listen. He decided to investigate Travis Taylor's 2017 suggestion (link) that a mirrored cavity of light would produce thrust by QI, but Tajmar thought of a simpler way to do it: fire infra-red light into a 2-d copper cavity. He tried several symmetric & asymmetric cavities and immediately, as expected, the one that was asymmetric produced the amount of thrust predicted by QI (140nN from 0.35W). Later tests though have shown less thrust either because the copper is slowly oxidising and is less reflective, or because he's eliminated experimental artifacts. The observed (?) thrust/power was 0.0004 N/kW.


Zbigniew Komala from Poland contacted me on twitter wanting to do a test. At Plymouth my DARPA-funded postdoc (Jesus Lucio) and I have developed a model that predicts which cavity shapes give the best thrust and we found that a Bart-cavity is pretty good (in the shape of Bart Simpson's head). So I asked Zbigniew to be the first to try that cavity. I am amazed by his work ethic, ingenuity and ability to manufacture cavities. He suspends his cavities on a spring and measures movements using a laser interferometer. He has found that the Bart drive does produce thrust of the expected size (30 microN from 20W). This is 0.00175 N/kW. The best thrust so far! Go Poland!

California, PD, USC.

I met Dr Ryan Weed (CEO of Positron Dynamics) at an Interstellar Studies meeting in the UK, last year when we were still allowed to meet with people. He suggested we work together. With Prof David Barnhart at the University of Southern California he put together a couple of fantastic bids for QI funding. One of which we won from CATIE (the California Aerospace Technology Institute for Excellence). The other is pending. The Californian team, delayed by covid-19, is now setting up the experiments. They aim to try the laser-into-a-cavity trick, but on a levitating track and in a vacuum.


Jamie Ciomperlik (aka monomorphic) is the latest explorer to have a go. He progressed remarkably quickly, going from "Hello" to "Here's the first result" in a couple of weeks. He's firing a laser into a 2-d cavity made of mirrors (see here) and using a torsion balance to detect thrust. He saw something that looked like thrust but at the moment it looks to be thermal. The trouble with his setup is that our Plymouth cavity model cannot predict what he should see since I do not know what his Q value is (it does not model glass yet) or how much of the light will escape from the 2-d open cavity.

All these teams have contributed something great. The Spanish team were the first QI experimenters. They showed interest before anyone else. The German team are very careful. They saw a thrust which impressed DARPA no end, and got me through to phase II of the project, but we shall see. The Polish team (Z. Komala) has done a brilliant job with the Bart drive and shows a lot of initiative, testing various other possibilities. I have great hope for the Californian and Atlantan teams, who have a tremendous American can-do attitude and great equipment.

Quantised inertia definitely works on galaxies and wide binaries. I believe it works on Earth as well and will produce thrust and energy that will revolutionise our society. This is testable, and every physics department should be testing it, instead they are rebuffing my attempts to talk to them because apparently I "make them feel uncomfortable". A shame, but I guess this is par for the course. All the more respect then to the engineering-oriented groups mentioned above who are testing QI and in three cases are being funded significant amounts to do so. Physicists please join in! One other suggested test is here. What you lose is dark matter for which there is no evidence after 40 years of hyper-expensive searching. What you gain is a stake in a new revolution that has brilliant astronomical evidence going for it (link), and maybe you'll get some funding too.

Tuesday, 16 June 2020

Pushing Off the Vacuum

Of course, some will claim that I have finally taken leave of my senses, but really, all I am doing is following quantised inertia to its logical conclusion. I have just published a paper titled 'Can nano-materials push off the vacuum?' (see references).

Physics already knows that the quantum vacuum can be damped (reduced in one area) by metal conductors. This is the well-known Casimir effect. It is now also well accepted that the quantum vacuum can be enhanced from the point of view of a high acceleration system. This is known as Unruh radiation. Quantised inertia then predicts that if such a system is made, such as a laser fired into a reflecting cavity, and the cavity is made asymmetric then the energised quantum vacuum will be damped more at the narrow end than the wide end and the cavity will be pushed towards its narrow end. It will move without having to expel propellant. In this way quantised inertia predicts the behaviour of the emdrive (see references). Quantised inertia implies that this is what nature has been doing since the dawn of time with inertia, where the quantum vacuum is damped by a relativistic horizons caused by acceleration, pushing objects back against that acceleration. This part of the theory is well backed by astronomical data - it predicts galaxy rotation without dark matter. It is an obvious next step to replace the horizon with a metal plate and make the old inertial process controllable.

So, what's new in this paper? Well, it turns out that you don't need the laser in the cavity or any energy input, if the cavity is small enough (about 129 nm). Then the zero point field itself is made inhomogeneous by the cavity's asymmetry and is strong enough to push the cavity, which is pretty light. Build a array of these nano-cavities and it should push itself, in the same way a boulder will roll down a hill. The hill in this case is the quantum vacuum, so the boulder may in fact be able to roll up a physical hill by 'rolling down' the one in the quantum vacuum. The applications are new launch systems and a way to get to the nearest stars in a human lifetime. A craft with propellant-less propulsion makes such a trip possible within a few years. A bold prediction indeed, but at least it is testable.

All that is needed is some way to build such a nano-cavity or an array of them, and then weigh it. Does anyone out there have a lab with photo-lithography or another technique that can build up a 3d matrix of nano-scale asymmetric metal cavities? If so, please email me and we can apply for funding to test the principle. The downside of failure would be some embarrassment for me, a small price to pay. The upside would be a space-based civilisation in our lifetimes & interstellar travel.

By the way, I have started publishing my sci-fi novel titled 'One Step to Tau Ceti' on patreon. It explains part of the philosophy behind quantised inertia in a, hopefully, amusing and entertaining way: https://www.patreon.com/OneSteptoTauCeti


McCulloch, M.E., 2020. Can nano-materials push off the vacuum? Progress in Physics, Vol 16, 2. http://www.ptep-online.com/2020/PP-60-02.PDF

McCulloch, M.E., 2017. Testing quantised inertia on emdrives with dielectrics. EPL, 118, 34003.

Saturday, 23 May 2020

Far and Away

Possibly the best way to test Quantised Inertia (except in the lab and the lockdown has postponed that for now) is to look at far distant (ie: high redshift) galaxies whose light is reaching us from an epoch a long time ago. This is because QI's predictions of galaxy rotation are very different from those of the standard model and MoND at high redshift. For the older theories the relation between the orbital speed of stars at the edge of galaxies (v) is of the type

v^4 = KM

where M is the visible mass and K, crucially, is a constant. How quaint! In quantised inertia the K is no longer a constant, since the inertial mass depends on the width of the cosmic horizon, and the formula is

v^4 = (2Gc^2/Theta)M

where G is the gravitational constant, c is the speed of light and Theta is the width of the cosmos, which varies with time. In the mainstream way of looking at it, this variation is because the cosmos is physically expanding. I prefer to assume that the information that local matter has about the cosmos is expanding, rather than the cosmos itself (this was also claimed by Halton Arp). Therefore in the past the cosmos, and Theta, were smaller and so, according to QI, all inertial masses and centrifugal forces were lower. Therefore far-off, ancient galaxies could afford to spin faster at the same mass and still remain bound.

As luck would have it, astronomers are just starting to see such galaxies and I talked about six of them in the paper referenced below (McCulloch, 2017). It turns out that they do indeed spin faster. Another one has just been seen at Z=4.2 which is called, romantically, DLA0817g or The Wolfe Disk (see Neeleman, 2020) and this means I can now compare QI with seven data points. I have summarised the data here:

The plot shows the observed acceleration of stars at the edge of the galaxies (y axis) and you can see that it increases with redshift (black dots). See the black dots. Note that the value for the galaxy at redshift Z=2.242 is aberrant and it looks like an outlier. The plot also shows (blue dots) the predicted accelerations assuming, as quantised inertia does, that the galaxies cannot slow below the minimum acceleration of 2c^2/Theta where Theta is the cosmic scale at the epoch the galaxy is in. So, to recapitulate, the higher redshift galaxies were in a smaller cosmos, so according to QI all inertial masses were lower, so they could afford to spin faster and still remain stable. You can see that the predictions of quantised inertia track the observed increase in spin quite well. This is not yet conclusive though, since maybe other effects are present. The next step is to compare what Newton/GR predicts for the same plot, but for that I need to find the masses of these systems, which is not as easy as it sounds since some masses are derived from the dynamics so include the dark matter fudge. What is clear from this is that the more high redshift galaxies we observe in this way the better!


Neeleman, M., J.X. Prochaska, N. Kanekar, M. Rafelski, 2020. A cold massive, rotating disc 1.5 billion years after the big bang. Nature, Vol. 581. Link

McCulloch, M.E., 2017. Galaxy rotations from quantised inertia and visible matter only. Astrophysics and Space Science, 362,149. Link

Sunday, 17 May 2020

Physics with an Edge & Thank Yous

Those with an keen eye may have noticed that I have changed my blog title from Physics from the edge to Physics WITH an Edge, which reflects the fact that QI predicts better than the old physics and is perhaps no longer at the fringe.

To my great joy, a couple of week ago my best friend at primary school, who is now an eminent surgeon, recently got back in touch after 40 years. One of my earliest and fondest memories is of talking to him about the need for interstellar travel during a sleep-over at his house. According to Nick Hornby friends are people who like what you like. So in his honour, I'd like to thank some of the people who have contributed to QI and who I regard as friends:

Alex Unzicker. When I first started publishing on quantised inertia I felt alone, since physicists did not seem to be interested in the old style of physics, that is data-driven with a dash of philosophy. Then I read this honest paper by Unzicker which is still one of my favourite reads and has been a inspiration to me: Link. More recently I have been reading his books and they are full of the same irreverent, data-driven and philosophical attitude. People often lament that theoretical physics would still be honest if Feynman was in it. Dr Unzicker provides the same role. We have skype'd in the past and I hope we can do so again many times. His latest book: Link

Jaume Gine. I first emailed Jaume in 2011 to mildly criticise his interpretation of my work and it is to his credit, and my gain, that we have collaborated on several papers since then. If you look at the record of our collaboration you will see that he is a more accurate mathematician than I am, and he has also prodded me towards interpretations of QI using thermodynamics. He is now helping me to publish a paper I've worked on since 1992 on the EPR paradox, adding the details that I omitted in my typically simple approach. Our most recent collaboration includes a complete derivation of QI just from Heisenberg's uncertainty principle: Link

Travis Taylor. I first came across Travis Taylor when he emailed me in 2017 to say that he'd written a paper about my work, but the journal had insisted he remove all mention of my work and put in dark matter! To his credit he emailed me instead. I suggested he submit to the J. of the British Interplanetary Society, which was at that time open minded, & it was published. Travis is Carl Sagan's ideal: both seriously competent and open minded, but the skill I most appreciate in him is making theories practically testable. In the aforementioned paper he pointed out that quantised inertia predicts that an emdrive based on visible light would work far better. His paper made QI more testable & DARPA contacted me shortly afterwards. His paper: Link

Jesus Lucio. When I received DARPA funding I advertised for a post-doc. If I'd received no applications it might have gone south, but luckily I received one: Dr Jesus Lucio. I really was saved by Jesus, and since then he has worked brilliantly, not only developing the cavity thrust model required, but adding a capability to optimise the cavity shape, in real time on the screen, and helping me with papers - particularly models and graphics. It is a shame that covid lockdown has ended our chats over coffee since I regard him now as a friend as well as a colleague and, sadly for me, he goes back to Spain next month. Our first published collaboration is: Link

There are many more people that I want to thank in future, such as M. Renda (who wrote the first serious criticism of QI - very useful to me), Z. Komala (who has been doing ingenious QI experiments) and others, but the four above make a nicely closed story for today. I will write another of these thank yous soon. I mean it: Thank you!