Archive for June, 2012

Library Anxiety

June 29, 2012
Didsbury Library

Didsbury Library in South Manchester. Not my favourite place.

I have just finished reading The Young Atheists Handbook by my friend Alom Shaha. The book interweaves Alom’s philosophical approach to life with his experiences as a child, an adolescent and an adult. And one of the most powerful influences in his early life, was his local library. He vividly describes how it formed a kind of portal into worlds very different from that in which he was growing up.

My wife feels the same way. As she recalls her childhood visits to the library she enters a kind of blissful reverie, and recounts how if she had understood that librarians were actually paid, she might well have chosen that as a career.

My sister and brother were both bibliophiles, and as children they worked their way through the library stock like gourmands at a never-ending buffet.

But not me. From the earliest age I remember libraries being places of fear and anxiety. Libraries were places of mysterious rules and codes which you might transgress by chance at any moment. They were places where you would be fined! In short, places it would be smart to avoid. At University I only entered the library because the single precious Commodore PET computer was kept in a small room in the basement.

I would like you to know that as an adult I have managed to overcome my anxiety and I can use libraries quite proficiently. And I generally find librarians to be extremely kind and helpful people. But I have never, ever, felt that I was welcome in a library.

This may be just me, and I may be unique in this anxiety. But I have often wondered whether anyone else had felt this way. Whether anyone else had -like me – been embarrassed to mention this in the face of the glorious tales of libraries told by the literati. Perhaps someone will let me know.

Climate contrarians spreading confusion

June 27, 2012

XKCD wrote a cartoon about my dilemma

I write this blog to stop myself going crazy: but those Climate Contrarians over at The Register keep pushing all my buttons! Take this extract from the end of a recent article

Meanwhile there’s reason not to panic even though the 450 ppm target will never be achieved [1]. US government climate modelling now suggests that warming will only just exceed 2°C – or even come in well below – at 780 ppm CO2.[2] It has become clear that the Antarctic ice cap actually froze into being while levels stood at 600 ppm, and that no matter what happens it’s going nowhere for thousands of years [3]. Many scientists suspect that the Sun actually has much more effect on climate than current climate science suggests [4], and major physicists believe a period of low solar activity is approaching which could usher in a “mini ice age” of the kind seen in the 17th and 18th centuries [5].


Even if none of those reasons not to panic contains the slightest grain of truth – even if it really is time to panic about carbon – in the real world picture now developing, activists would surely be well advised to abandon their various marginal crusades – against meat, against mythical fat people, against wasted milk, against hosepipes and farting camels and coffee and all the rest of the silliness, and try to make a case for action that has some internal consistency. ® [6]

Let’s look at these six points in turn:

[1] Panic isn’t what anyone wants to create. We have lots of problems facing us(e.g. feeding ourselves, keeping healthy, world population etc.), and climate change is one more. Panic won’t help with any of them, but a sense of urgency and importance is appropriate. Why does The Register mock people’s perfectly reasonable concerns?
[2] Climate Sensitivity. By how much does global mean temperature change when carbon dioxide concentrations double? We don’t know, but estimates range from roughly 2 °C to 4 °C . It could be much larger, but even the smallest of these figures will usher in significant climate change. And if the permanent arctic ice cap disappears – as seems likely – then all of these calculations become irrelevant . Furthermore we are (realistically) going to at least double CO2 levels. Slowing down emissions now would probably be a good idea. Why doesn’t The Register recommend that?
[3] The Antarctic Ice Cap formed 34 million years ago when the continents were in different places. In particular the Atlantic and Pacific Oceans were connected through the Central American Seaway. The growth of the ice cap was triggered by the breaking off of South America from Antarctica which created a circular weather system which ‘sat’ on the south pole and reduced the flow of the heat from the equatorial regions. Frankly, the concentration of Carbon Dioxide in the atmosphere was a tiny perturbation on that kind of  gigantic change of oceanic and atmospheric circulation. Why does The Register write this irrelevant nonsense?
[4] Solar output has been pretty constant, and is certainly not responsible for the recent warming seen on Earth. Why does The Register write this irrelevant nonsense?
[5] The ability of scientists to predict solar behaviour is limited. At the moment all predictions are based on statistical correlations with previous solar behaviour. If there was a reduction in solar output and a mini-ice age that would probably help reduce global warming, but it is completely out of our control or knowledge. Why does The Register write this irrelevant nonsense?

and finally the truth

[6] The Register is fed up with ‘silly stories’ about Climate Change. Well so am I! But what I try to do is sift the wheat from the chaff. Climate Change is a serious issue and serious journalists should take it seriously.

Michael Gove and the Exam Boards

June 24, 2012
Michael Gove

Michael Gove: Not always wrong.

What do you do when someone with whom you basically disagree, says something sensible? Michael Gove has placed me in this situation three times now.

Firstly he abolished the Qualifications and Curriculum development Authority (QCDA).  Secondly he pointed out at that school IT lessons are at best uninspiring. And now he has gone and acknowledged that our system of competitive exam boards has driven down GCSE standards.

You may not have noticed this because he also called for GCSEs to be replaced with ‘O’levels. I sympathise with his motivation – to raise the bar for the most academically able pupils – but I think he is wrong on this. It would be enormously disruptive, enormously divisive, and there is actually nothing inherently wrong with GCSEs.

The problem with GCSEs lies in the ‘almost corrupt‘ link between publishers and their ‘pet’ exam boards. The BBC report Gove’s comments thus:

“We want to tackle the culture of competitive dumbing-down, by making sure that exam boards cannot compete with each other on the basis of how easy their exams are”

Gove is correct that the exam board/publisher conglomerates have driven down standards. These  conglomerates consist of a not-for-profit exam board, and a large publisher who tunes their (very profitable) books to optimise pass rates with their own particular board’s exams. Additionally the scope of the GCSE syllabus has been aggressively reduced.

As a result GCSEs have come almost useless. Despite the obsession with passing the exams, the results have lost their meaning. They do not discriminate amongst the most able students, and the pass level is so abysmally low that a level ‘C’ no longer indicates a significant achievement. This is a national disgrace and Gove is absolutely correct to name it

The BBC also report protestations from Exam Boards. I have no sympathy. They have spent the last two decades driving down standards in this almost corrupt manner, while generating massive profits for their partner publishing companies. I look forward to their abolition. Publishers should publish books, not exams.

Cars, lorries, batteries computers and satellites.

June 22, 2012
Volvo car train

A convoy of cars. Each car was driving at 52 miles per hour just 6 metres from the car in front. It was perfectly safe because the cars sensed each others movements. Picture courtesy of the BBC. BBC Courtesy of my licence fee 🙂

It is easy to dwell on the negative. But having recovered from my ill-advised journey into central London the other week, I have to admit that things are changing on the roads. And generally for the better. Consider these examples.

  • My friend John has traded in his Jaguar (25 miles per gallon: 11.3 litres per 100 kilometres) for a Ford Fiesta (70 miles per gallon: 4.0 litres per 100 kilometres). The savings he makes each month will more or less pay for the car. The only things which have changed are that (a) less carbon dioxide is emitted as he travels to and from work and (b) he has a better quality radio to listen to.
  • The BBC story of Volvo’s road convey describes a group of cars which automatically synchronise their motions to travel at optimum speed on a motorway. Technology such as this could lower fuel consumption and improve congestion and allow you to read a book while driving! What could possibly go wrong?
  • Electric cars are now useable. They are still expensive, but given the general evolution of the price of technologically novel products, it is not unreasonable to expect that to change. As an example consider the new Vauxhall Ampera, a mixed petrol engine and electric vehicle. If you travel less than around 35 miles each day, then it will work entirely electrically. If you travel further – up to 300 miles – a petrol engine operating at its peak efficiency will generate electricity for the motor. It gets a pretty good review even from the Register.

And we are a long way from the limits of thermodynamic efficiency. The Ampera has a 111 kW motor. For a car weighing 1 tonne, an 11 kW motor  – one tenth the power of the Ampera – would accelerate to 30 m.p.h in a perfectly acceptable 8 seconds and would reach 50 m.p.h after 30 seconds.

I mention these stories merely to point out that because fuel prices are high, innovation is now possible in the formerly closed sphere of road transport. Developments in batteries, computer vision, and satellite technology have made progress possible in ways which were barely conceivable even 10 years ago. In another 10 years, things will have changed again: who knows how. But things are changing.

Efergy e2 Wireless Electricity Monitor

June 20, 2012
Efergy e2

The Efergy e2 wireless electricity meter.

A while ago I reviewed a previous Efergy wireless electricity meter and commented on its usefulness, but noted that the unit wasn’t very accurate – it was about 25% in error when compared with my domestic electricity meter. In order to find that out,  I had to read the daily total of units used off the screen of the unit, and plot the data on a spreadsheet and then compare it with the domestic electricity meter over a period of many months. Not many people can be bothered with that type of kerfuffle.

But the device was still useful. Occasionally I would look at the amount of electricity being used in the house, and then walk around switching things on and off and see how much the consumption changed. However, the unit could only really detect changes in consumption of about 10 watts and so the readout could be a little bit noisy, but it was still useful.

A couple of months ago I was contacted by Efergy who asked me if I would like to test their new wireless unit, the Efergy e2. This one should be very accurate because it works by piggy-backing on the domestic electricity meter: simply measures the flashes of light that the meter produces for every one thousandth of a kilowatt hour (an electricity unit) that it uses. Additionally the unit connects to a PC or Mac and data can be downloaded to allow the user to monitor consumption trends over time. It sounded fantastic: accurate and convenient. I happily agreed to review the unit and Efergy kindly sent me one – free of charge! I always knew writing this blog would pay off one day!


The basic setup of the unit was easy – and I was quickly monitoring electricity consumption. However, the software installation was not so straightforward. Installation on my iMac was ridiculous, requiring installation of 3 separate programmes and then a re-start. And after all that, it still didn’t work. Efergy really need another way to do this. Installation on PC was a little more straightforward requiring only that I downloaded an up-to-date version of the software from their web site.


Efergy Software

The Efergy e-link Software. It has a non-standard interface, quirky controls, the scaling of the graphs is random and there is no way to get at your own data. Click for a larger version.

Once the connection problems were sorted out, I downloaded some data from the unit to the PC. The software allows you to see how your consumption has varied hour-by-hour through the day, or day-by-day through the month. However, the controls are quirky and non-standard: the graph’s scale changes from one day to the next making it difficult to visually compare one day with another; the units it uses to plot the data are -effectively – random numbers; and the writing is so small and written in green on grey so that it is almost unreadable.

However, after instruction from Efergy I did manage to download data to my PC – Ahhh!…At last I felt like I was in control. The software saves the data in an old Excel file format which is easy to open and plot. The graph below shows the number of kWhs used, averaged over a period of 1 hour – effectively the average power consumption – hour by hour for the last month. I could also have just downloaded the total number of kWhs used daily. Why the built-in software can’t plot these graphs is a mystery to me.

This is just the kind of data I love to see. I don’t mind the peaks on this graph – they are the dishwasher and the tumble dryer – but this data tells me that no matter what I do, my house uses around 350 watts of electricity (more than £1/day or £365/year) whether I am at home or not! I will get to the root of that!

Electricity Consumption

Electricity Consumption Click for larger Graph


Aside from reviewing your energy usage, one of the key uses of this type of device is to walk around one’s home and see the effect of switching things on and off – Efergy call this the ‘Energy Now’ function*. The previous model was just about OK at this, but it wasn’t very accurate at low power levels – as I mentioned above the readings fluctuated by a few watts making the useable resolution around 10 watts. But the technology Efergy have employed in this unit is potentially much more accurate. By simply recording the time between pulses from the electricity meter, they could have made an extremely accurate meter with a resolution of around 1 watt. But instead they chose not too – apparently in a bid to extend battery life. IMHO this was a poor decision.

Instead of recording the time between pulses, the unit records ‘How many pulses occur in 30 seconds’. Let me explain. For a typical meter, houshold consumption of 120 W will cause one pulse per 30 seconds. 240 W  will cause two pulses per 30 seconds etc. If you are using say 180 W, then sometimes there will be one pulse in a 30 second period, and sometimes there will be two. This unit will tell you that your electricity usage is oscillating between 120 W and 240 W and you will wonder what is switching on and off. But nothing is. In short the ‘Energy now’ function has measurement resolution of 120 W – around 10 times worse than the previous version of this unit, and functionally useless. Grrrrr…

The idea of piggy-backing on existing metering technology is smart and Efergy tell me that future units will incorporate my suggestion for measuring the time between pulses and so those units will also be very sensitive for monitoring consumption in the ‘Energy now’ mode. Sadly existing units won’t be able to be modified.

And presumably they will eventually make software that doesn’t irritate people and which works on Macs.

The selling point of this unit is the ability to download data to a PC and to look at usage over a long period of time in detail. This is very valuable and personally I would buy it just for this function. When they sort out the ‘Energy Now’ issue this will be a great little unit which I would recommend to anyone.

You can find the Efergy web site here

* It should be ‘power now’ not ‘energy now’, but Efergy say they used this metrological inexactitude in order to communicate more clearly.

Climate Contrarians and Miocene Warmth

June 18, 2012

This is the second of two articles focussing on stories highlighted by the Climate Contrarians over at the Register.

Over the last 0.8 million years, the mean temperature of the Earth’s Surface has been highly correlated with the atmospheric concentration of carbon dioxide. The figure below shows the data over the last 0.4 million years and there is an obvious correlation between global mean temperature (blue: inferred from the relative amounts of oxygen isotopes found in water in ice cores) and atmospheric CO2 concentration (green: deduced form the concentration of CO2 in bubbles in the ice). Very roughly 100 ppm CO2 corresponds to around 10 °C of warming – a truly terrifying statistic if it holds for warming as well as cooling. The role of carbon dioxide is perfectly clear.

ICe Core Data

Graph of atmospheric concentration of CO2 (Green graph) and Global Mean temperature (Blue graph), deduced from the Vostok, Antarctica ice core as reported by Petit et al., 1999.The data are plotted at ‘thousands of years before the present, so ‘now’ is on the left of the graphs and the past runs over to the right. The main oscillations arise from changes in Earth’s orbital eccentricity, tilt, and precession called Milankovitch cycles. The correlation between CO2 concentration and global mean temperature is very clear. Picture taken from wikipedia, but other versions are available.

Into this clear situation The Register highlight a paper in Nature called Late Miocene decoupling of oceanic warmth and atmospheric carbon dioxide forcing  with the natty headline:

10 million years ago there was less CO2 – but the Earth was WARMER.

The unspoken implication is that scientists don’t understand the Climate or the role of carbon dioxide, and so maybe carbon dioxide is not necessarily causing the current bout of global warming. This implication is mischievous. Just to put the time scale into context, there were of course, no human beings alive during this era. Our evolutionary path is unsure but modern humans probably evolved a little over 1 million years ago.

All those years ago, the continents were not in very different positions from the present day: for example the Atlantic was only around 100 km narrower. And so one might assume that oceanic and atmospheric circulation were probably similar. However, it is well known that this was not the case.

One of the key differences was that the Central American Seaway closed around 5 million years ago, creating a land bridge between North and South America. This closure process – partly volcanic and partly caused by plate movement – gradually split a single pan-global ocean into two, creating separate Pacific and Atlantic Oceans. Other sea passages have also changed significantly over this period, for example the Bering Straits, which affects communication with the Arctic Sea. But the closure of the Central American Seaway is probably the most significant.

This article by the Woods Hole Oceanographic Institute  explains how this process dramatically affected oceanic and atmospheric circulation and led to the creation a few million years later of the Arctic ice sheets. Incidentally, the article points out that the Antarctic was already frozen at this point, an event triggered by the opening of the another ocean-linking region. The opening of the gap between the tip of South America, and the northern end of the Antarctic Archipelago around 34 million years ago allowed circumpolar weather systems to stabilise over the Antarctic, de-coupling it from the transport of heat from the Equator.

The closure of the Central American Seaway around 5 million years ago is thought have gradually affected circulation between the Atlantic and Pacific Oceans

The closure of the Central American Seaway around 5 million years ago is thought have gradually affected circulation between the Atlantic and Pacific Oceans. These figures are collated from The Woods Hole Oceanographic Institute web site Oceanus. Click for larger version.

So in the era under discussion, ocean and climate circulation is known to have been significantly different from the present day. Given this background, the paper presents evidence from isotopic analysis of fossils for both sea-surface temperature and carbon dioxide concentration in the atmosphere – amazingly difficult data to get!

The key experimental result of the paper is shown in the figure below. The upper part shows estimates of sea surface temperatures rising as we go back in time by roughly 1 °C for each 1 million years. The lower part shows estimates of carbon dioxide concentration. I have added the current level of atmospheric CO2 concentration for reference. The gist of the paper is that back to around 5 million years ago, the elevated sea surface temperature is correlated (roughly) with CO2 concentration. But further back CO2 concentrations are lower, while sea surface temperature remains high.

The link between atmospheric carbon dioxide and global mean temperature is very clear from ice core data (purple) back to 800,000 years ago. Going back further to about 3 million years ago the data on carbon dioxide concentration are very widely spread and beyond 4.5 million years ago, there is very little data. To the extent that the older data is trustworthy, it indicates that 10 million years ago atmospheric CO2 was about the same level as it was in the late twentieth century (roughly 350 ppm) but the estimated global mean temperature was around 10 °C  warmer.

The main author LaRiviere suggests some ways in which, with a radically different oceanographic and atmospheric circulation, this de-coupling of global temperature and carbon dioxide concentration might have occurred. In particular, he highlights fossil evidence for differences in the temperature profile of the surface layers of the oceans.

Miocene modified 2

Despite reading the paper several times, I confess I could not follow all his arguments in detail. However I doubt The Register had studied the paper at all, because they make no mention of this radical change in oceanographic circulation. Instead they conclude with a quote from the author:

“It’s a surprising finding, given our understanding that climate and carbon dioxide are strongly coupled to each other,” LaRiviere says.
“In the late Miocene, there must have been some other way for the world to be warm.”

The Register‘s implication is that ‘this other way’ has not been understood by modern Climate Science. And indeed it hasn’t been fully understood: that’s why this is a paper in Nature! But LaRiviere is doing his best.

Does his paper yield any insight on our current situation? In my opinion, not directly. However:

  • It does highlight how relatively small geographic changes can radically affect Earth’s Climate.
  • It does highlight that ice free arctic regions were possible with a world around 10 °C warmer than the present day
  • It does highlight that the estimated 0.75 °C warming in 100 years that humans have achieved is a little bit less than a MILLION times faster the rate of temperature change seen on the Figure.

However these are not insights to which the Climate Contraians over at the Register wish to draw to our attention. Instead they relish confusion. How I wish they would instead take the time to present scientific papers in context, and then instead of this turgid article, I could write short articles saying what great journalists they had, and we would all be the wiser. C’est la vie.

Climate Contrarians and Glacier Retreat

June 18, 2012

Have you ever met people who just love to disagree? These contrarians revel in discord, and over at the ‘technology news’ website  The Register, they have a pile of them.

I wouldn’t normally care about this, but in addition to its regular news and views about the computer industry, The Register frequently comments on issues related to Climate Change. They don’t have a well-defined editorial view that I can discern, they just disagree with things.

One pernicious technique they use for spreading confusion is to report current scientific papers as ‘news’ items. This is fair enough in itself,  but they select only papers reporting apparently ‘odd’ results. By missing out the broader context of the work, the articles imply that this particular paper changes views radically, something which is rarely true. In fact, the reporting is the journalistic equivalent of gleefully poking sticks into the spokes of a bicycle wheel.

Let me give you a couple of examples of this stick-pokery. The first concerns glacial retreat and the second (in a following article) concerns estimates of pre-historic global temperature in the era before the Arctic developed its current ice sheet. Researching these articles has taken hours and has felt like the tedious equivalent of mending a bicycle wheel into which someone has poked a stick.

Global Glacial Retreat Large
Global Glacial Retreat. This chart shows records of the numbers of glaciers which advance (BLUE) or retreat (RED) in different parts of the world. Notice the different scales on each chart. The bottom chart is the sum of the all the previous charts. Note also that the data are not exhaustive and glaciers which are stable are not counted. Click for a much larger version of this graph.

As I mentioned in a previous article, and as the figure above makes clear, we are living in an era of near global retreat of glaciers. However, this retreat cannot be blamed directly on global warming, anthropogenic or otherwise – because it began in the nineteenth century, before global temperatures rose substantially. So why are the glaciers retreating?

The best efforts at understanding this consider that the retreat in each region is due to different factors, but that global warming and changes in global climate are probably a contributory factor in explaining why the same ‘regional factors’ are causing a near universal, simultaneous and accelerating retreat.

Into this situation The Register chooses to highlight a paper which has unearthed aerial photographs of glaciers in Greenland from the 1930s. Now I didn’t actually read the paper concerned: so taking The Register‘s reporting as correct, the pictures show glacial retreat at an even faster rate than today. As the figure above shows, this is not news.

Looking at the admittedly scant early Arctic data, we see that this datum is not anomalous in any way. The paper simply adds one more point to the 30,420 points we already have. However, by highlighting the paper The Register  implies that it somehow punctures arguments that carbon dioxide is associated with global warming.

“It now appears that the glaciers were retreating even faster eighty years ago: but nobody worried about it, and the ice subsequently came back again.

The implication is that global glacial retreat is just ‘a natural phenomenon’ and that anthropogenic influence is incidental.

So they have taken a perfectly innocent paper and spun its contents to make it look like the science behind our understanding of climate is in disarray. Which it isn’t.

Click here to find out The Register’s views on the effect of carbon dioxide in Miocene Era around 10 million years ago.

The data for the figure came from Chapter 5 (pdf) of a report to the United Nations Environmental Program, but you can also find data at the World Glacier Monitoring Service:

Previous articles on Climate Sceptics can be found here, here, here and here.

Man-Made versus Natural

June 14, 2012

An object that I found in my garden this morning. ‘Man-made’ or ‘natural’?

As an undergraduate I attended a lecture by the inspirational Eric Laithwaite. He began by asking the audience to imagine a device which could pump water from 30 metres below ground to 30 metres above ground, but which was completely solar-powered. We pondered… and he then showed us a picture of a tree.

He then spoke about the difference between ‘natural’ and ‘man-made’ solutions. As I recall the talk through the haze of age, I seem to remember that he just asked questions: one question after another with no answers. And I was enthralled.

One question I remember in particular was:

“How was it that we could instantly recognise objects as having been either ‘man-made’ or ‘naturally’ produced?”

I was reminded of this when I viewed a video of a 4 gram domino knocking over a 16 kilogram domino.

This system is obviously made by humans. And it struck me keenly that I was witnessing the physical embodiment of the financial system, created entirely by humans and which is currently ‘looking after’ my pension investment.

And the ‘natural’ pension investment? Well they are in bed now 🙂

Vacuum Bazooka

June 13, 2012

Today I spent a few pounds and a couple of hours with my son making a bazooka. Is there a better way to pass a Sunday afternoon?

Our adventures were cut short by rain, but I hope that next week we may be able to find the tweaks that will double the projectile speed to perhaps 30 metres per second.

The project is described in a new book (The Ultimate Book of Saturday Scienceby a colleague from Air Products, Neil Downie. Neil is a man on a mission to get people doing things – preferably things to do with science and engineering. If you like the sound of this but don’t know where to start, this book will give you inspiration, enough information to get started, and a description of the science involved. What it won’t do is tell you exactly what to do. I am sure this is deliberate.

I built this bazooka by copying pretty much what was in the book – copying is just such a great way to learn! But there are so many variables that it is inevitable that everyone who builds one of these projects will have to invent something for themselves as they go along. And it is by doing this that people will take ownership of the projects – and I am sure that would make Neil smile.

Christian and I may have begun by copying, but when we have finished, that bazooka will be ours!

The Ultimate Book of Saturday Science

The Ultimate Book of Saturday Science by Neil Downie. A source of inspiration for science projects that will takeabout an afternoon.

We are still a little way from raw rambo-esque figure of the naked scientist strutting the halls of the Royal Institution!

But just give me a rain-free weekend!

Noticing the obvious

June 11, 2012
Electrical Neutrality

An artistic visualisation of the concept of equality of positive and negative electrical charges.

I tidied my office last week, and flicking through my pile of ‘papers to read later’ I came upon:

The electrical neutral neutrality of atoms and of bulk matter
C. S. Unnikrishnan and C.T. Gillies
Metrologia 41 (2004) S125-S135

The basic question asked in the paper was:

  • Is the electrical charge on the electron equal in magnitude to the electrical charge on the proton?

Or alternatively:

  • Is bulk matter electrically neutral?

What struck me about the paper was ‘Why had I never asked either of these questions myself?“. I think it is because I had somehow thought the answers were ‘obvious’ or ‘self-evident’, but in fact they are neither. They are -IMHO – bloody good questions!

Ultimately the questions are experimental, and a number of clever techniques have been used to provide the answers. So far we know that the charge on the electron and the charge on the proton are equal in magnitude to within 1 part in 1021. Wow! I don’t know of any other two experimental numbers that are known to be equal with that degree of precision.

Electrons have a completely different internal structure to protons and neutrons. Electrons are part of class of particles called leptons (‘light’* ones) which as far as we know have no internal structure. Protons and neutrons are part of class of particles called baryons (‘heavy’** ones)  and we know they are in some sense composed of quarks. Each proton or neutron is composed of three quarks.

Given the completely different structure of each type of particle, the equality of the magnitude of the electric charge on each goes from being ‘remarkable’  to ‘astounding’! And even though we  have no fundamental explanation of what electric charge is, it is shocking to find that two types of particle with completely different structures should have exactly the same amount of it – whatever ‘it‘ is. In fact, I refuse to believe it. It seems inevitable that we we will eventually discover some tiny difference between the magnitude of the electric charge on the proton and the electron.

What would the consequences of such a discovery be? Unnikrishnan and Gillies covers these in some detail but two points caught my attention. The first was a comment by Einstein noticing that if normal matter were not exactly neutral, then when it flowed, it could generate a magnetic field.

The Earth and Sun have magnetic fields, the orientation of which stand in approximate relationship with the axes of rotation… But is hard to imagine that electrical conduction or convection currents of sufficient magnitudes are really present… It rather looks as if the cyclic motions of neutral matter are producing magnetic fields.

And the second was an empirical law proposed by Schuster who noticed that the strength of the magnetic field around a range of planets and galaxies was linked to their respective angular momenta. Could that be evidence that bulk matter is not perfectly neutral?

Now these suggestions are highly speculative, and I am sure that people cleverer than I have worked out all kinds of reasons why they do, or do not, make sense. But whether or not they turn out to be true, I feel like I have had my sense of what is ‘normal’ re-adjusted. I am left with the sense that something I experience everyday – the neutrality of bulk matter – is not in any sense obvious.


* Light in the sense of low mass rather than in the sense of electromagnetic radiation

Heavy in the sense of high mass rather than in the sense of really serious

%d bloggers like this: