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Monday, 23 February 2015

Return after a short absence

This blog has lain fallow for a little while as I had to attend to other matters, most notably helping to run RepRapPro Ltd and moving house.  But soon I shall return...

Wednesday, 10 October 2012


A while ago my brother put on some music after dinner.  "Who?" he asked me.

"Ashkenazy," I said.

"Correct.  Page turner?" he asked...

Of course it was terrible musical snobbery for us both to know implicitly that he was asking for the performer and not the composer (Chopin, as it happened).  And his subsequent question made me laugh for a long time.  Perhaps we had drunk too much wine.

But every musician needs a page turner, or there is that annoying half-second pause as one hand flies from the keys to flip.

There are, of course, page turner apps.  But as far as I can see they all rely on foot pedals.

However tablets have microphones.  It can't be hard to write a program that analyses the sound stream, matches it to a score, and then turns the page automatically...

Tuesday, 8 May 2012


James Lovelock and Richard Dawkins famously disagree over Lovelock's Gaia Hypothesis.

Dawkins' extremely strong counterargument against Gaia is that natural selection works at the level of the gene, and that it doesn't have any foresight to anticipate long-term planetary disaster in the face of an immediate pressure to select for a locally advantageous mutation.  As a counterexample to Gaia, there are the cyanobacteria.  They all but destroyed the Earth's entire ecosystem just after it first got started by dumping billions of tonnes of poison waste (oxygen) into the atmosphere.  And, of course, one counterexample is enough to disprove a hypothesis.

However, most of the evidence we have seems to support Lovelock.  For example, the sun has been getting steadily hotter, and yet conditions on Earth have been maintained more or less homoeostatically by the collective undirected actions of all its living organisms.  Lovelock simulated a self-regulating world of light and dark daisies (called, naturally, Daisyworld) that exhibited self-regulating temperature even though the participating organisms were only acting in their immediate self interest.  But this did not include a mutation that had an active interest in disrupting the homeostasis - something that is always a possibility in reality.

When he was working for NASA, Lovelock pointed out that a good indicator of life on another world would be (as it is on Earth) a surprisingly low-entropy state on its surface.  As an example, consider the oxygen again - oxygen is a highly reactive gas (hence its toxicity to primordial life); one would not expect unaided geological processes to create such a low-entropy atmosphere.  If we ever find an exoplanet with an ocean of molten sodium on its surface, we can be tolerably confident that that planet supports life.

One thing that all life needs is low-entropy.  You eat bread, which has a low entropy, and your subsequent living actions dump the energy in your bread as waste heat, which has high entropy.  In that way you, and all other living organisms, are behaving just like the steam engines of the nineteenth century which led thermodynamicists to the idea of entropy in the first place.  And when you plant a field of wheat for bread, you are contriving symbiotically with the wheat to use the Sun's energy locally to reduce the entropy of a part of the system.

Indeed, it is in the interest of all living organisms to have low-entropy surroundings.  That makes their life most easy to conduct (it is more-or-less equivalent to saying that they need a plentiful local source of food, clean water, and breathing air), and genes that cause them to create such a state in their local surroundings will - all other things being equal - be favoured.  Ants grow fungus farms for food.  Plants encourage symbiotic micro-organisms around their roots.  Spiders make larders in their webs.

One of Dawkins' great contributions to biology is the idea of the extended phenotype.  That is, the idea that genes can be selected for that drive organisms to alter their surroundings for their benefit.  Birds have genes that allow them instinctively to build nests - a nest is part of a bird's extended phenotype.  People have genes that allow us to converse, and hence to collaborate.  The results are our extended phenotypes of iPhones, power stations, and TV talent shows.

But - as we established above - there is a selection pressure on every living organism to reduce the entropy of its surroundings.  Genes will have been selected in all living things to cause them to try to create local extended phenotypes of such surroundings.  None of this is global; no organisms (not even we) have evolved to stabilise the planet.  But the collective effect of all the local attempts to reduce entropy is exactly the Gaia that Lovelock proposed.  It is not a globally directed effort by each individual (let alone each individual gene), any more than a water molecule in a steam engine is trying to make a flywheel go round.  But the collective unconscious action of all the water molecules is, nonetheless, to achieve precisely that.  And the collective unconscious action of all organisms is to create a global low-entropy environment.

Dawkins would correctly argue (I think) that given global low entropy created by Gaia then there is a selection pressure on organisms to exploit that as a whole, thus destroying it in a tragedy of the commons.  And that is precisely what the cyanobacteria did.

So the question that remains is: why are cyanobacteria events so rare?  The answer is Dawkins' own Mount Improbable.  An organism that mutates to exploit low entropy in general must do so locally at first by a small mutation.  And almost all those organisms suffer the usual fate of over-successful predators: they eat too much of their immediate surroundings and then starve.  For random change to generate a mutation that allows excessive exploitation on a global scale in a singe shot is an astronomically improbable event.  But it happened once with the cyanobacteria.  However, they didn't quite destroy everything, because they had a direct line to the Sun itself, and so they could survive the disaster they created.  Any organism without such a get-out-of-jail-free card would succumb to the predator starvation effect, and so leave pockets of other life (along perhaps with themselves) to start evolving afresh in balanced competition.

So Gaia is not a globally-directed system with a homeostatic purpose.  It emerges naturally as the result of all living things trying to reduce the entropy of their immediate surroundings using the power of the sun for their own benefit.  And Gaia is not proof against global cataclysm, nor against very very rare mutations that allow a single organism to exploit the system as a whole and thus destroy it.

For the first time in two billion years such a new species has emerged.  It also has a direct line to the Sun.  It is the species who's extended phenotype includes making these out of the bare earth...

Monday, 10 October 2011


It is beyond argument that democracy is the best form of government that humanity has implemented so far.  It may not be the best possible form of government (see here, for example), but it's the best we've tried.  Democracies are the richest societies on Earth; their populations have the longest life expectancy; and they have the worst immigration problems (which is another way of saying that everyone else wants to live in them).

But there is a superficial paradox: democracies are intrinsically inefficient compared to, say, dictatorships in the same way that a mob is less efficient than a disciplined army, and for the same reasons.  So why should an inefficient form of government work best?  The obvious answer - that government in itself is a bad thing and that less of it is therefore better - falls at the first counterexample: Somalia has no government at all, and it is one of the most unpleasant places to live in the World.

Democratic politicians are no less venal and corrupt than politicians working in other forms of government (read any newspaper for proof); indeed it is reasonable to suppose that much the same people would be running the government regardless of the political system under which they found themselves operating.  Think of any minister in your government and visualize him or her serving under Robert Mugabe ("I think it's best to work for change from within.").  It's not a big leap of imagination, is it?

No.  The reason that democracy works is not because it puts the right people in government.  There are no right people to be in government because no human being - you, me, Barack Obama, Wen Jiabao; none of the seven billion of us - has the faintest idea how to run a country.  (We merely all have opinions about how it should be done, which is not the same thing at all.)  The reason that democracy works is because it has a solid mechanism for removing people from power.

Having no government is bad (Somalia).  Government by the same people for a long time is bad (Zimbabwe).  But high turnover among governors is good.

It follows that, in an election, we should all ignore the record of the incumbents, we should all ignore the policies of the candidates, and we should all ignore their personalities.

We should simply vote in the way that is most likely to remove the current lot (whoever they are) from office.

Friday, 7 October 2011


There are two main evolutionary theories of altruism: Fisher, Haldane and Hamilton's idea of kin selection, and Trivers' idea of reciprocal altruism.

Neither of these theories is mutually exclusive and both may operate together.  I would like to propose a third that may also be operating.

It is this.  Your fitness is increased if you associate with altruistic people, whether you yourself are altruistic or selfish.   In the latter case the others may well find you irritating, but even then - all things being equal - the others are less likely to act against you than more selfish people would.  Thus we would expect all individuals to seek out altruistic company.

People are inclined to have children with those with whom they associate, simply because of opportunity.   When altruistic people have children with other altruistic people that will tend to reinforce impulses towards altruism in their children (though we should be cognizant of the regression to the mean).  And when selfish people have children with altruistic people, that will tend to dilute selfish impulses.

Thus we should expect altruistic behaviour in the population as a whole to rise in response to the statistical effect that everyone is more likely to have children with altruistic people than they are with selfish people, simply because of the breeding opportunities provided by the ubiquitous preference for association with the altruistic.

This principle does not just apply to altruism and selfishness.  For example everyone - whether well or ill - will have a preference for associating with people who are well because the associators will then be less likely to catch something nasty from the associatees.  Thus we should expect disease resistance to rise, even above the rise that would be expected anyway simply because disease resistance is in itself intrinsically evolutionarily fitter.

Thus, let X be a characteristic possessed by animal A.  If, by associating with A, animal B increases its fitness regardless of whether B possesses X or not, then we would expect the proportion of X in the population to increase. 

Note that I said "animal" - animals are motile and associate voluntarily.  This principle should apply to any organism that can move about and decide who its friends are, and it will apply particularly strongly in social species (us, say, or bats).  But plants, for example, and solitary animals (leopards, say, or polar bears) will be much less likely to exhibit the principle.

I have decided to call this selection by associative opportunity.

Wednesday, 28 September 2011


Some professions seem highly heritable.  Think of the number of famous writers and actors whose parents did the same thing.  Though less publicly obvious, engineering is a highly heritable profession too.  (Anecdotally, I am an engineer and my father was an engineer, as was my maternal grandfather.)

And yet, no one seems (i.e. I did one Google search...)  to have studied this.  There are - literally - gigabytes of public records in the form of marriage certificates in the like that simultaneously record the jobs of both parents and their children, so it ought to be straightforward to rank professions by their heritability.  There would probably be a bias towards father/son relationships that would mirror the inequity in job opportunities in past ages (and today...), but it ought to be reasonably straightforward to control for that in such a large statistical sample.

A ranking of professions by heritability would serve as  rich basis for all those entertaining nature/nurture arguments about human characteristics, as well as for some serious genetic and developmental studies...

Wednesday, 21 September 2011


Money is not evolutionarily stable.

By this, I mean that no living organism would ever evolve by natural selection that had a system of exchanging worthless, but hard-to-forge, tokens for items of value with other organisms (either of its own species, or of another).

Firstly, it is obvious that this has never happened.  No living thing has - or has ever had - a system equivalent to money.  This could be simply because the money mutation has never been chanced upon by natural selection.  But in fact it goes deeper than that.  Such a mutation would be less fit than its competitors and would die out, as I shall show.

But hang on, you say, people are naturally-evolved living organisms, and people use money.  Yes - but human money is a temporary aberration; our money is about to succumb to the forces that have prevented its evolving and surviving elsewhere in nature.  Indeed, we have just started to see the first signs of its mortality. 

Before we go on, note that there are plenty of bartering systems in nature.  Nectar is exchanged for pollination; sugary fruit is exchanged for the distribution of seeds.   But nectar and fruit have real value; they cost real energy to synthesise and their consumer gets some of that real energy back; they are like you obtaining your groceries by giving the shop 20 litres of petrol.

So why don't plants give bees a nectar token that the bees can cash in for a meal later, or maybe exchange with a house martin for a nest site?  The reason is the phrase "hard-to-forge" that I started with.  Such a scheme would put a selection pressure on the bees to forge the nectar tokens so they could get free nectar (or nest sites).  And they would succeed because, like all living things, they make everything atom by atom.

Nothing, and certainly no worthless token, is unforgeable if you construct everything atom by atom, and this is the reason that money is evolutionarily unstable. 

The picture above is of a forged keyboard on an ATM machine designed to clone credit cards.   The latest scam is to use 3D printing to make these.   Eventually 3D printers will be using atomic force microscope technology to build everything they make atom by atom.  Coins, bank notes, and credit cards will be among the simpler items to manufacture.

At that point money becomes valueless.  We will be left with just the encryption-based schemes like Bitcoin in its place.  Except that we won't, because one of the items that atom-by-atom 3D printing will probably give us is the quantum computer, which allows anyone to crack all the encryption schemes currently in use.  Maybe money will survive in the form of quantum encryption, but that seems far from certain.

If the ability to make anything kills money, how fortunate it will be that we will coincidentally have just aquired a universal technology that will allow people to make everything that they want for themselves without money...

Thursday, 4 August 2011


Dr Sam Peters stepped carefully along the island path.  It was nine in the morning, and under the leaf canopy the air was still cool, though the tropical sun was glinting fiercely off the sea ahead through the trees.   She came to one of her traps, which was empty.  She renewed the bait in it, then carried on.  The ultrasound detector clipped to her belt was silent.

After another thirty meters she arrived at the spot where she had gathered a fecal sample the week before.  Though heavily contaminated by bacterial DNA, her analysis had suggested that this was left by that rarest organism: a mammal new to science.   Her next trap was just a little further, on the other side of a fallen branch.  As she got to it and looked over she could see that it was occupied.  She smiled and climbed across.

The trap contained a mouse-like animal with a squashed and deformed nose.  It had enormous ears.  Dr Peters' smile expanded to a laugh of delight.  The animal had vestigial membranes between its front legs and its body.  It was a bat, flightless because of the lack of predation on its remote home.   As she carefully removed it from the trap, the ultrasound detector chirped.

That little story was not intended to be about bats, though it would be credible where there still to exist such a remote island any more on Earth.  It was about the smile and the laugh - regardless of the rest of the story, you didn't trip over those details as being implausible.

Jimmy Carr, who knows a thing or two about laughter, says that all jokes work the same way: you set up a situation in the listener’s mind, and then reveal the true situation to be otherwise by the punch line.  He was not the first to point this out.  The listener's laughter is a pleasurable response to a realisation that they were mistaken, but are now enlightened. 

Our sense of humour is our scientific sense, distilled, our facility for systematic falsification, amplified.

There are many measures of different aspects of intelligence, and psychologists labour long to try to devise unbiased tests to quantify each.  There's everything from Spearman's familiar g, to the latest: my old friend Dylan Evans's Risk Intelligence.  But, as far as I am aware, no one has yet devised a proper psychometric test to quantify sense of humour, h.

It seems to me that devising a way of measuring h is long overdue.  And, once it has been established, it would be most interesting to try to correlate h with creativity and scientific innovative ability, and - differently - the ability to test scientific hypotheses.