At the NAM in Manchester

Last Thursday I attended one day of the UK-Germany National Astronomy Meeting in Manchester and I gave a talk in the (unofficial) Cosmology 4 'Dark Energy, Dark Matter and Modified Gravity' session on my recent work 'Testing quantised inertia with wide binaries'. I was asked a few interesting questions. Someone asked me whether I'd applied MiHsC/QI to the Cosmic Microwave Background (CMB). I have done some work on this: I can model the apparent supression of power at the largest scales using the Hubble-scale Casimir effect, but haven't taken account of curved space yet, and further: that CMB anomaly does not poke outside the error bars yet.

One chap suggested that I could look at photons since they traverse areas of low acceleration. OK, but looking for a more direct test, I am now trying to focus on either very simple astronomical tests (wide binaries) or terrestrial experiments (lab tests). He also said that I should not cite the Pioneer anomaly as a successful test any more because Turyshev et al. have modelled the Pioneer anomaly as a mundane thermal radiative reaction force: heat emitted from the RTGs bounces off and pushes the craft. However, although I haven't yet read their paper in detail, it seems they have used a complex reflection model with many adjustable parameters (tricky) and also I would have expected there to be a significant decay in the Pioneer anomaly if radiation was the cause since the RTGs should have significantly cooled over the 30 years of data, but Anderson et al. saw no decay in the anomaly. Turyshev et al. claim there is a decay. I need to look at the data to decide this.

Anyway, someone then asked 'Can you tell me anything that would convince me that inertia is caused by Unruh radiation'. That nonplussed me because I'd just presented all my comparisons of MiHsC/QI with the data and the agreement with data is what convinces me. Anyway, I answered: 'My main reason is that it works'. By this I mean that if you do assume that inertia comes from Unruh radiation, and the Hubble-scale Casimir effect which follows, then you get successful experimental predictions that are unobtainable from other theories. I do not yet have a specific physical model for exactly how the Unruh radiation might interact with objects and cause inertia (I think this is what this person wanted, but for me that has to come later, and slowly). I have a few ideas about possible mechanisms, but no experiments to discriminate between them yet.

Sheldon's nightmare scenario.

Speaking of inertia: it affects subjects too. I'm sure it would horrify the character of Sheldon on The Big Bang Theory, but most of standard physics has been developed over the past three hundred years by people familiar mostly with the working of human-made machines. The implication is that theory reflects technology. This has led to a physics that predicts simple things well in the short term, but restricts us to the view that the machine-universe is running down to its inevitable heat death. I like to think instead that the universe is growing, in a way more akin to organisms or the www, and that now we are starting to understand biology and computing, which require us to use the idea of information, physics will have to be overhauled to take this view. Of course, this may be all new-age hot air, unless an experiment can be suggested that can discriminate between this new 'informatics' and the old physics.

I have lots of fun imagining Sheldon & Wolowitz from the Big Bang Theory (modern versions of Plato and Aristotle) discussing this idea. For example, how's this?:

Wolo: So...Sheldon. How about this idea that theoretical physicists get their paradigms from engineers?
Shel: Hokum, and I have some empirical data to disprove it.
Wolo: OK, bring it on!
Shel: Do I ever listen to you?
Wolo: Granted, but you can't base your argument on one data point.
Shel: Howard, I'm a theoretical physicist. I don't even need one data point!
Wolo: This is nonsense. Even you can't ignore objective reality!
Shel: Alright (sigh), if you insist on dragging mundane reality into it, then you know me to be a subscriber to the many-worlds interpretation of quantum mechanics.
Wolo: So?
Shel: I can assure you, that in none of those many worlds do any Sheldon's listen to you... That's an infinite number of data points right there!
Wolo: Note to self: don't argue with crazy people.

Zen and the Art of Physics?

Last night I dived back into an old favourite: R.M. Pirsig's Zen and the Art of Motorcycle Maintainance, and found an anecdote that summarises a point I've been longing to make: why naive observation is a good thing. Here it is: a teacher asks his students to write an original essay about their home town. One student finds that she cannot write anything original about this abstract concept, so the teacher tells her to focus on an actual house in the town. She notices an interesting brick and is immediately able to say original things about this brick and work outwards from there.

I like this vignette because it illustrates a problem I have with the tendency in modern physics, art and other subjects, to model things that cannot be directly observed or tested. For example, abstract art, or, in physics: the big bang. For me, studies of the big bang represent humans hubristically trying to impose whatever is going on inside their heads (standard physics) on the universe, rather than humbly allowing the universe to change what is going on in their heads (ie: by learning). The solution is to allow reality to inspire new ideas, most efficiently by looking for observational anomalies closer to home (interesting bricks) without presupposing any theory.

Experiments and logic

At the moment the OPERA faster than light (FTL) result is far too uncertain to be trusted, and needs replication, but, in an article just published in New Scientist [1] (see below) R. Garisto argues that: "models which explain [the FTL] by breaking relativity are ruled out". He says he knows this because a recent paper by Cohen and Glashow [2] proposed that a neutrino going faster than light "may lose energy rapidly by bremsstrahlung", and the OPERA neutrinos did not, so they cannot have travelled FTL. Surely there is an error in logic here, since Garisto is effectively saying: you cannot violate standard physics unless you do it using standard physics.

Travelling faster than light violates standard physics in about the biggest way possible, and it is wrong to reject theories that explain experimental results (as Garisto says he has) by saying that they violate standard physics. Such an attitude would doom fundamental physics to an endless sterility. In physics, experiment (even if later shown to be flawed) must come first. If the OPERA result is supported experimentally, then standard physics is going to have to mumble sheepish apologies, and new physics will be needed. My point here is not that I think the OPERA result is necessarily correct, but rather that, in cases like this, objective logic should be applied, rather than a blind faith in standard physics.

[1] http://www.newscientist.com/article/dn21515-lights-speed-limit-is-safe-for-now.html
[2] http://prl.aps.org/abstract/PRL/v107/i18/e181803

Underlying randomness

One of the courses I teach is climatology, and I try to emphasise both the observations and the maths and theory. In climatology there are a lot of simple balances. For example (to simplify): in the north Atlantic the wind pushes the water up into a wide bump centred on the Azores and the ocean currents flow clockwise around this bump producing Coriolis forces inwards that balance the pressure-gradient forces outwards. This produces a simple circular pattern (in geostrophic balance). I think this illustrates an interesting point: systems, like the ocean, jiggle around randomly, until one day, by chance, they find a balance, and it is the nature of balances, once set up, to remain, since they are stable. By the time we get around to observing it, and for most of the time, this simple balance is what we see. I guess this also applies to the rest of physics and is behind the simplicity and predictability of what we see in the world, but the crazy underlying randomness is always there, ready to return.

Wide binaries

There has been a great observational study done recently by Hernandez et al. (see: http://arxiv.org/abs/1105.1873). They have looked at wide binary stars and found that when they are separated by 7000AU or more, so that their accelerations decrease below 2*10^-10 m/s^2, then their behaviour becomes non-Newtonian, in that their orbital speeds are so large that the centrifugal (inertial) forces separating them should be greater than the gravitational pull inwards from the mass that we can see, so they should zoom off to infinity. A similar behaviour is seen in galaxy rotation curves, which deviate from Newtonian behaviour below this same acceleration. For these simple binary systems, it is hard to see how dark matter (DM) could kick in at a particular acceleration, and Newton and MoND both predict only about 1/10th of the orbital speeds seen. This provides a experimentum crucis, and so I have recently been testing MiHsC on these data: because of their low acceleration, MiHsC predicts a decrease in the stars’ inertial masses so they manage to orbit each other at the faster speed without inertia separating them. The orbital speed predicted by MiHsC is still only 1/2 of that seen, but this is much better than the 1/10th from Newtonian dynamics and MoND. I have just today submitted an abstract on this to the UK’s National Astronomy Meeting (NAM 2012).

Comment on Tajmar's latest experiment

I've just been emailed by a fellow who wanted to know whether Tajmar's latest paper (8th Nov, in which he finds no anomalous signal outside the cryostat) contradicts MiHsC. The answer is no: in both my papers testing MiHsC on the Tajmar results (the later one is: http://arxiv.org/abs/1106.3266) I stated that MiHsC predicts a very fast decay of the anomalous signal from the gyroscope with its distance outside the cryostat, since, outside it, nearby thermal accelerations dominate over the acceleration of the ring or the fixed stars in their effect on the gyroscope's inertia. So it is no surprise to me that Tajmar found no signal outside the cryostat. Tajmar, in his latest paper (see the last sentence, before the acknowledgements) also refers to my work and this aspect of it.