Light in a box & the Emdrive

In 2011 I was invited up to St Andrews University to talk about MiHsC (The title of my talk: Can inertia be modified electromagnetically?). Their physics department has a superb reputation so I was a little nervous. I met some of the academics and sat down to have lunch with them and one of them asked incisively: "If MiHsC is true then why don't we see the inertial mass of something in a metal box reduce?". Well, at the time I nearly choked on my tuna sandwich, but in fact this was one of the first questions I asked myself in the early days, and, when I got my voice back, I explained that for the accelerations of objects we are familiar with, the Unruh waves are extremely long. For example, an object with an acceleration of 9.8 m/s^2 will see Unruh waves 7x10^16 m long (a few light years) and Faraday cages do not affect such long EM waves (submarines can receive long EM waves). Also, as some of the lecturers there helpfully pointed out: Unruh waves are not solely EM waves, they're waves in all the fields.

How about light in a box though? If you have photons in a box whose inner sides are mirrored, then they do contribute an inertial mass to the box because if you move the box one way, then the photons bash into the mirror on the backwards side and so contribute to the inertia that opposes the box's motion. So light or photons in a box, have inertial mass. The interesting thing about the photons in a metal box is their fast speed, so that the mirrors are forcing them to accelerate rapidly backwards and forwards. That means the Unruh waves associated with their inertia are now of a similar wavelength to the box's size and they can be damped by its walls, at least  their EM component. So MiHsC predicts a loss of inertial mass for the light in the metal box, just the same as it predicts a much smaller loss of inertia for objects inside the Hubble volume.

Now what if the box is a cone? (EMdrive) The photons are resonating within it so the Unruh waves they see are of a similar size to the cone and typically fewer Unruh waves will fit or 'be allowed' at the narrow end of the box than at the wide end. One way of thinking about this is that the photons going from the narrow to wide end gain inertial mass in a new MiHsCian way. This turns out to be a bit like the old rocket method of blasting hot gas out of the wide end, but now we are blasting 'virtual' mass. To conserve momentum (mass*velocity) the whole system has to move the other way. Hence the typical motion of the Emdrive towards its narrow end. MiHsC predicts the results quite well without any tuning parameters, see earlier blogs or my paper on MiHsC and the Emdrive here (an introduction to MiHsC is here).

Note that, if the EM waves' frequency is tuned so that the Unruh waves fit better within the narrow end, then the Emdrive might actually move the other way, and it would be interesting to know whether this was the case for the recent NASA experiment where it did actually move the other way. I'm now working on a second paper, that takes into account individual Unruh waves, to be submitted..

Reference

McCulloch, M.E., 2015. Can the Emdrive be explained by quantised inertia? Progress in Physics, Vol. 11, 1, 78-80 (Pdf).

The Magnificent Anderson

John D. Anderson has done it again! It seems every few years he discovers a fascinating anomaly, and his papers are great for data-driven theorists like me because he publishes while freely admitting not to know the cause: old-style empiricism.

In 2005 I read the mammoth papers of Anderson et al. (1998, 2002) which first presented the Pioneer anomaly to the world (although most now consider this explained with a complex thermal model, I do not agree). In 2008 I read his (to me) 'mind-bomb' observational paper on the spacecraft flyby anomalies in which he pointed out an intriguing symmetry of these anomalies about the Earth's spin axis, which at the time sent me into a roller coaster of emotions, made me obsessed with applying MiHsC to it, and stimulated me into realising that MiHsC could explain it if I used 'mutual' accelerations (discussion). A crucial step.

Now he's back with a paper in the journal EuroPhysics Letters (Anderson et al., 2015, see refs) looking at the values of Newton's gravitational constant (big G) that have been puzzling alert physicists for years. G can be measured by suspending a dumbbell arrangement of two masses from a wire and then bringing a known mass up to a distance r away from one of them, and measuring the twist in the wire to work out the force (F) of gravitational attraction. Newton's F=GMm/r^2 then gives you G because M, m, r and F are known. Mysteriously, the 13 recent values of G found using this method vary by more than the likely error in the experiments, which suggests the real uncertainty is bigger, because something unexpected is going on.

The new result is that Anderson et al. (2015) have found that most of the 13 values of G vary with a pattern: a sine curve with a period of 5.899+/-0.062 years. Intriguingly they point out that Holme and de Viron (2013) showed that the length of our day varies with the same period. Anderson et al. (2015) argue that the changes in G cannot be causing the length of day changes, since a greater G would shrink the planet, spinning it up and reducing the length of day: the opposite to the correlation seen. It is possible that something else is influencing both G and the length of day, but what?

I've been fascinated by these unexplained variations in G for a while, and I attended a Royal Society workshop about it last year. I have found a 'weak' correlation in values of G with latitude, and I have been trying to investigate links with MiHsC, with no success so far. The new periodic pattern in G shown up by Anderson's paper is a potential clue, and at the limit of science any clue is priceless.

References

Anderson, J.D., G. Schubert, V. Trimble, M.R. Feldman, 2015. Measurements of Newton's gravitational constant and the length of day. EPL, 110, 10002. Paper

Holme, R. and O. de Viron, 2013. Nature, 499, 202. Paper

End of The Magnificent Amberson's by Orson Welles: Old-style George Amberson wanders around a polluted city, confused and disoriented by the industrial society that has developed around him.

Doubtful to the end

Aristotle said "The mark of an educated mind is to be able to entertain an idea without necessarily accepting it" and I'd say the mark of a health society is to be able to discuss any idea openly without censoring it. This applies to physics too. I developed MiHsC by looking at controversial data like the Pioneer anomaly (even more controversial now!) with an attitude of not necessarily accepting the anomaly, but just seeing whether it was explainable in a new way. As soon as you start either blindly believing in what you are doing, or on the other hand become too wary of what others think, you become sterile and lose the sense of curiosity or fun that is necessary to continue. I remember Feynman once felt he got himself out of a sterile hole by writing 'Disregard (others)' on his blackboard. In science, doubt and data are crucial.
 

This is a creeping problem in our society, in that avenues of exploration are being closed down and data is being ignored by people who feel they have the final answer. No-one has the final answer, and if someone ever claims to, speak calmly and run quickly! It's best to allow everyone's ideas to be debated openly, because you never know where a useful answer will come from. Look at physics: the first action-at-a-distance theory of gravity was inspired by Newton's obsession with alchemy, back then a dangerous and wrong-headed idea, but nevertheless stimulating. If a problem has been around for awhile, like galaxy rotation today, the answer never comes from an acceptable direction, because those have been tried already.

This is a quote (from Pais, 1982) that has intrigued me for years: 'Einstein wrote this to his old friend M. Besso, one year before his (E's) death: "I consider it quite possible that physics cannot be based on the field concept, ie: on continuous structures. In that case nothing remains of my entire castle in the air, gravitational theory included and the rest of modern physics".'. This shows that although Einstein's main thrust was in the opposite direction to me (from general relativity to quantum mechanics), he had a healthy doubtful attitude to the end, and occasionally considered non-continuum physics, eg: horizons, which MiHsC is based on.

References

Pais, A., 1982. Subtle is the Lord (see page 467).

Abstract for NAM2015

Here's the abstact I recently submitted to the 'Cosmology Beyond the Standard Model' session of the UK's National Astronomy Meeting 2015 (NAM2015). Hopefully they'll accept it (they didn't) but, if not, it can have its day in the sun here:

Testing quantised inertia on cosmological scales
Mike McCulloch

The galaxy rotation problem and cosmic acceleration both occur in extremely low acceleration environments. It is shown that these anomalies can be explained by a model that assumes inertial mass is caused by the effect of horizons on Unruh radiation. The wavelengths of this radiation become longer for low accelerations so that a larger proportion of the radiation spectrum does not fit exactly within the Hubble horizon (and partial waves would allow us to infer what lies behind the horizons, which should not be allowed). This model (called Quantised Inertia or MiHsC) leads to a predicted new loss of inertia at very low accelerations and so predicts galaxy rotation and cosmic acceleration, and some other anomalies, without adjustable parameters. It also suggests a reason for the large-scale cosmic microwave background anomaly recently confirmed by the Planck satellite. The model needs to be tested more rigorously on the galactic scale, hence the need to present at NAM 2015 to make contacts to help with this.

Physics X

In 1665, Henry Oldenburg started the journal called: Philosophical Transactions of the Royal Society. This was one of the first scientific journals, and it presented new observations in pure form without necessarily any theory attached, so that theorists could think about the observational data in whatever way they wanted. The Royal Society also had a motto "Take no one's word for it" which freed them up from the old theories of giants like Aristotle and enabled them to look at new data unbiased. This kind of attitude led to the first great blossoming of modern physics in the form of Robert Hooke and Isaac Newton.

This data-first attitude is in danger in modern physics and needs to be resurrected (the ancient Greeks had about 300 years of observational scientific discovery and then detached from nature to reflect on abstract philosophies. There are signs that we are too, with untestable string theory..etc). As an example, at a scientific meeting of the Royal Society on big G, I mentioned to a bigwig over breakfast that the unexplained variations in big G had a dependence on latitude (this dependence is weak, but present). He discounted this immediately by saying 'No, there's no mechanism to explain that'. This sort of theory-first thinking is very common now, and it is exactly the wrong attitude. If an anomaly appears, it is worthy of inspection, particularly if it disagrees with theory. This common sense has somehow been lost and physics has become a self-congratulation club detached from nature. Feynman lived long enough to see the beginning of this rot, and critically said in his tough Brooklyn accent: 'Nature will come out as she is!', meaning that human expectations are not relevant, only the data is, and indeed Nature is happily being weird with increasing frequency: anomalous galaxy rotation, spacecraft anomalies, superconductor anomalies, muonic hydrogen proton radii, LENR, cosmic acceleration, sonoluminescence, the emdrive, large scale CMB anomalies, aligned quasars and many more mysteries. The only response of mainstream physics so far has been to attribute some of the deviations to invisible entities, as if we're back in the middle ages, and it doesn't help that it is almost impossible for experimentalists to publish many of these anomalous results.

That is why I think there should be a new journal, a rebooted 'Transactions' if you like, but maybe called 'Anomalies' or 'Physics-X' which publishes anomalous observations, so long as they have been carefully done with attention paid to errors. This is the most useful kind of observation. I think this would be the best way to jump start physics and get people to look up from old books and look at the new anomalies out there in the real world, some of which I have discussed in my previous blogs (and some of which can be explained by MiHsC). We don't have to decline into untestable metaphysics like the ancient Greeks (string theory..etc) and end up back in a dark age. Instead, like Asimov's Hari Seldon, we can take action now to keep physics looking at the real world and moving forward.