Brian Clegg's Blog, page 136

What goes around comes around

Another Fred and George, now sadly no
longer with usI've always been interested in the things that inspire writers of fiction. I'm not talking about that painful interview question 'Where do you get your ideas from?'  which makes every writer cringe. That is silly indeed. But there are certainly things that point writers in certain directions over and above the output of their own creative juices.

I was inspired to think about this in a big way while re-reading, for a spot of summer light relief, one of the P. G. Wodehouse Jeeves books - to be precise, The Inimitable Jeeves. It struck me that consciously or unconsciously J. K. Rowling (notice a similarity in the authors' names?) must have been influenced by a pair of characters in this book.

Specifically there are twins, named Claude and Eustace, who are at college when we meet them. This pair are always up to mischief, either simply causing havoc or, if possible, running dubious schemes to make themselves cash. Does this sound at all familiar?

I don't know if Fred and George Weasley were a conscious hat tip to P. G. from J. K. or simply inspired by a session reading Wodehouse long before that was not directly remembered - but either way it is hard to believe that Claude and Eustace were not prototypes of the mischievous Hogwarts entrepreneurs.

I don't think this is a bad thing, merely worthy of note.

Are you a humanist?

Are you a humanist? Should you care? Take a look at this short, interesting video featuring some quite well known people talking on the subject, and then I'll share my thoughts with you.



Okay, what did you think? My feeling after watching it is that I quite like a lot that goes with being a humanist, apart from one huge assumption that all those taking part seem to make, which is that if you are a humanist you must be an atheist. You see, I think the most scientific religious viewpoint to take is to be an agnostic, and I don't see any conflict with being a humanist.

If you are an atheist you say 'I refuse to be open minded. I KNOW what the truth is and no evidence will sway me.' I don't think that's scientific. As an agnostic, I would say I don't think there is clear evidence either way, so it would be silly to take a Dawkinsesque stand on the subject.

Just to draw a parallel with a science issue, take the business of string theory. There is no evidence for string theory - it is totally untestable at the moment. Now the atheist view would be to say 'Because string theory is untestable, I will assume it doesn't have any validity and I will mock people who do think it's worth giving time to. We don't need string theory, we can get along perfectly well without it.' But as an agnostic I would say 'Okay, we don't have evidence either way yet, so let's suspend judgement until we do. I want to hear more about string theory and I will not mindlessly attack it. And frankly it would be very upsetting to all those people who have given their (working) lives to it, so I will be a little more considerate.' I know which sounds the better approach to me.

I have one other problem with this video, which is the section on death. I think all those smug, middle class, wealthy (mostly middle aged) people have a very specific view of how you can make the best of life and enjoy it to the full. It's a bit harder if you are a starving infant expected to die before your first birthday. I think they totally underestimate the comfort that religion has given to many people in dire conditions. This doesn't make religion true - but it does make the humanist view of death, as stated in this video, very much a view that would appeal best to a group of comfortable, privileged intellectuals with a good long life expectancy.

So will I be asking to join the British Humanist Association? I don't think so - but I genuinely thank them for a thought provoking video that raises some serious and important issues.

Hanging with the Gecko

This is the third in my Nature's Nanotech series also featured on www.popularscience.co.uk




If you’ve ever seen gecko walking up a wall, it’s an uncanny experience. Okay, it’s not a 40 kilo golden retriever, but we are still talking about an animal weighing around 70 grams that can suspend itself from a smooth wall as if it were a fly. For a gecko, even a surface like glass presents no problems. This is nature’s Spiderman.

It might be reasonable to assume that the gecko’s gravity defying feats were down to sucker cups on its feet, a bit like a lizard version of a squid, but the reality is much more interesting. Take a look at a gecko’s toes and you’ll see a series of horizontal pads called setae. Seen close up they look like collections of hairs, but in fact they are the confusingly named ‘processes’ – very thin extensions of the tissue of toe which branch out into vast numbers of nanometer scale bristles.

These tiny projections add up to a huge surface area that is in contact with the wall or other surface the gecko decides to encounter. And that’s the secret of their glue-free adhesion. Because the gecko’s setae are ideally structured to make the most of the van der Waals force. This is a quantum effect resulting from interaction between molecules in the gecko’s foot and the surface.

We are used to atoms being attracted to each other by the electromagnetic force between different charged particles. So, for example, water molecules are attracted to each other by the hydrogen bonding we saw producing spherical water droplets in the previous feature. The relative positive charge on one of the hydrogen atoms is attracted to the relative negative charge on an oxygen. But the van der Waals force is a result of additional attraction after the usual forces that bond atoms together in molecules and hydrogen bonding have been accounted for.

Because of the strange quantum motion of electrons around the outside of an atom, the charge at any point undergoes small fluctuations – van der Waals forces arise when these fluctuations pair up with opposite fluctuations in a nearby atom. The result is a tiny attraction between each of the nanoscale protrusions on the foot and the nearby surface, which add up over the whole of the foot to provide enough force to keep the gecko in place.

Remarkably, if every single protrusion on a typical gecko’s foot was simultaneously in contact with a surface it could keep a heavy human in place – up to around 133 kg. In fact the biggest problem a gecko has is not staying on a surface, but getting its foot off. To make this possible its toes are jointed unusually and it seems to secrete a lubricating fluid that makes it easier to detach its otherwise dry but sticky pads.

Not surprisingly, there is a lot of interest in making use of gecko-style technology. After all, master this approach and you have a form of adhesion that is extremely powerful, yet doesn’t deteriorate with repeated attaching and detaching like a conventional adhesive. A number of universities have been researching the subject.

The first publication seems to have been from the University of Akron in Ohio, where a paper in 2007 described a gecko technology sticky tape with four times the sticking power of a gecko’s foot, meaning fully deployed gecko-sized pads could hold up around half a tonne. With these on its feet, a 40 kilogram golden retriever would have no problem walking up walls – the only difficulty would be managing to apply enough force to detach its paws as it walked. In the tape, the gecko’s setae are replaced by nanotubes of carbon fibre which are attached to a sheet of flexible polymer, acting as the tape.

The great thing about carbon nanotubes, which are effectively long, thin, flexible carbon crystals, is that they can be significantly narrower than the smallest protrusions from a gecko’s foot. A typical nanotube has a diameter of a single nanometer – pure nanotechnology – maximising the opportunity for van der Waals attraction. Within a year, other researchers at the University of Dayton (Ohio again!) were announcing a glue with ten times the sticking power of the gecko’s foot.

Such adhesives are available commercially on a small scale, offering the ability to stick under extreme temperature conditions and to surfaces that are wet or flexible that would defeat practically any conventional adhesive. We can expect to see a lot more gecko tapes (like the Geckskin product) and gecko glues in the future.

There have been other theories to explain the mechanism of the gecko’s foot, including a form of capillary attraction, but the best evidence at the moment is in favour of van der Waals forces. This seems to be borne out by the problem geckos have sticking to Teflon – PTFE has very low van der Waals attractiveness. To find out more about the gecko’s foot (and other technological inspirations from nature) I would recommend the aptly titled The Gecko’s Foot by Peter Forbes.

The action that keeps a gecko in place is a dry application of natural nanotechnology, but the more you look at the nanotech biological world, the more you realize it’s mostly a wet world. In the next feature in this series we’ll look at why conventional ‘dry’ engineering often won’t work on nanoscales and how we need to take a different look at the way we build our technology, bringing liquids into the mix.

Image from Wikipedia

In which we go bonkers in the Languedoc

I quite often get asked if I'd like a book for review. If it's not self published and it's a science book, it's usually an easy yes. With fiction, it's very much a matter of whether or not it tickles my fancy - hence the review a while ago of Miss Peregrine's Home for Peculiar Children . So when I received the offer of Carla McKay's The Folly of French Kissing, not an obvious choice of reading for me, I at least weighed up the pros and cons.

On the plus side it was set it France, which I love, and the puff comments ('The Gallic equivalent of something out of Midsomer Murders...') caught my eye. I like a touch of murder if it's British in feel, and this was an ex-pat novel. On the downside it really wasn't the kind of book I usually read (and the cover, according to the chick-lit convention, seems to suggest it's aimed at women).

Now the publisher did themselves no favours sending me a bound proof to review. I hate reading from bound proofs - they don't look and feel right (this one had a blank white cover), and there's always something irritatingly wrong with the text - in this case a whole repeated page (which I hope didn't make it to the printed version). But I persevered and on the whole I'm glad I did. It's a novel of three parts.

At the beginning, when we're being introduced to the ex-pats we'll find in an obscure part of the Languedoc, and how they got there, it's a bit slow. I also was beginning to worry this was a self-published book, as there were a few writing issues that needed some stern editing (more than the requisite zero adverbs, for example). But once we got into the main middle section the style picked up a little and the plot got some pace. Before long I was tearing through it, wanting to find what happened next. For older readers I could best describe it as a girlie version of Leslie Thomas - a lighter touch, but a similar feel in many respects. Like Thomas there was a slight tendency to 2D secondary characters - there was a bluff northerner who was straight out of central casting - but the main characters were quite well drawn.

Then came the final section where the strings were drawn together. I found this a little disappointing as it seemed rushed and a little calculating.

Altogether it was interesting to dive beneath a chick-lit cover, something I would never normally do. The Midsomer Murders hint was entirely misleading - there is crime in it, but not in the way that would give you to expect - but on the whole I enjoyed the experience of The Folly of French Kissing. Ideal for a hot weather, lightweight summer read. See at Amazon.co.uk and Amazon.com

Time to pull on the Lycra

It's Royal Society of Chemistry podcast time again, and hard though I may try, I can't totally ignore the Olympics.


What does 'The Olympics' say to the compound-loving chemist? The achievement? The national pride? No! The Lycra. We may mock the weekend cyclists puffing along in their shiny Lycra shorts, but the fact is it's an essential these days for many sports. And Lycra turns up in some surprising places. So maybe it's time to slip into something stretchy and find out more. Take a listen.

Causality vs correlation in military domestic violence

Does this get you pregnant?Sorry if that title sounds a bit like an obscure scientific paper, but there's an important point to make. I was listening last night to a radio documentary about domestic violence among military personnel and it made the most fundamental scientific blunder. It missed a phrase that should be tattooed on the hand of every broadcaster: 'Do not confuse correlation and causation.'

Let me take a step back with an example that was used on my Operational Research masters course. For a good few years after the war, the pregnancy rate in the UK had a strong correlation with the import of bananas. When more bananas were imported there were more pregnancies. Fewer bananas, fewer pregnancies.

The amusing response is that the bananas were causing the pregnancies. But to accept that at face value is to miss two other possibilities. One is simple reversal. The pregnancies could be causing the bananas. By this I mean that there could be a causal connection between someone being pregnant and increased consumption of bananas. Maybe pregnant women crave bananas. Or maybe young children (a common  result of pregnancy) eat more bananas than older people.

The second, and much wider, option to explain the apparent link is that there is a third factor that causes both the increase in pregnancies and the increase in bananas. Perhaps there was more money around and this caused both. Or one of many other potential third factors.

I am not suggesting any of these alternative causal processes is correct, but that it would be absolutely stupid to make the initial assumption that because banana imports went up and pregnancies went up, eating bananas make you pregnant.

Now let's go back to that radio programme. Because it made just such a stupid assumption. Let's be clear again - I'm not saying what the causal link is, merely pointing out the unscientific way in which correlation was turned into a particular causality.

The topic of the radio programme was essentially that, despite denials from the MOD, there was more likelihood of domestic violence in an army household than a civilian one. The big, bad assumption was that being in the army (and the experiences you had there) made you a more violent person. There was no attempt whatsoever to look at the two alternative causalities. What if being a more violent than average person made you more likely to join the army? Was the causality the reverse of the one they assumed? For that matter could there be a third factor that caused people join the army and to be more violent?

This was sloppy journalism and bad science.

Nature’s Nanotech #2 – The magic lotus leaf

This is one of a series of articles co-hosted with www.popularscience.co.uk Living things are built on hidden nanotechnology components, but sometimes that technology achieves remarkable things in a very visible way. A great example is the ‘lotus leaf effect.’ This is named after the sacred lotus, the Nelumbo nucifera, an Asian plant that looks a little like a water lily. The plant’s leaves often emerge into the air covered in sticky mud, but when water runs over them they are self cleaning – the mud runs off, leaving a bare leaf exposed to the sunlight. Water on a lotus leafOther plants have since been discovered to have a similar lotus leaf effect, including the nasturtium, the taro and the prickly pear cactus. Seen close up, the leaves of the sacred lotus are covered in a series of tiny protrusions, like a bad case of goose bumps. A combination of the shape of these projections and a covering of wax makes the surface hydrophobic. This literally means that it fears water, but more accurately, the leaf refuses to get too intimate with the liquid. This shouldn’t be confused with hydrophobia, a term for rabies!Water is naturally pulled into droplets by the hydrogen bonding that links its molecules and ensures that this essential liquid for life exists on the Earth (without hydrogen bonding, water would boil at around -70 Celsius). This attraction is why raindrops are spherical. They aren’t teardrop shaped as they are often portrayed. Left to their own devices, water drops are spherical because the force of the hydrogen bonding pulls all the molecules in towards each other, but there is no equivalent outward force, so the water naturally forms a sphere.The surface of the lotus leaf helps water stay in that spherical form, rather than spreading out and wetting the leaf. The result is that the water rolls off, carrying dirt with it, rather like an avalanche picking up rocks as it passes by. Because of the shape of the surface pimples on the leaf, known as papillae, particles of dirt do not stick to the surface well, but instead are more likely to stick to the rolling droplets and be carried away. As well as letting the light through to enable photosynthesis, this effect is beneficial to the leaves as it protects them against incursion by fungi and other predatory growths.Although the papillae themselves can be as large as 20,000 nanometres tall, the effectiveness of these bumps is in their nanoscale structure, with multiple tiny nobbly bits that reduce the amount of contact area the water has with the surface to a tiny percentage. After the effect was discovered in the 1960s, it seemed inevitable that industry would make use of it and there have been several remarkable applications.One example that is often used is self-cleaning glass – which seems very reasonable as the requirement is identical to the needs of the lotus leaf – yet strangely, what is used here is entirely different. Pilkington, the British company that invented the float glass process, has such a glass product known as Activ. This has a photo-catalytic material on its surface that helps daylight to break down dirt into small particles, but it also has a surface coating that works in the opposite way to the lotus leaf. It’s an anti-lotus leaf effect.The coating on this glass, a nanoscale thin film, is hydrophilic rather than hydrophobic. Instead of encouraging water to form into droplets that roll over the glass picking up the dirt as they go, this technology encourages water to slide over the surface in a sheet, sluicing the dirt away. In practice this works best with heavy rainfall, where the lotus effect is better at cleaning surfaces with less of a downpour – but both involve nanoscale modification of the surface to change the way that water molecules interact.Increasingly now, though, we are seeing true lotus leaf effect inspired products, that make objects hydrophobic. A process like P2i’s Aridion technology applies a nano-scale coating of a fluoro-polymer that keeps water in droplets. The most impressive aspect of this technology is just how flexible it is. Originally used to protect soldiers clothing against chemical attack , the coatings are now being applied to electronic equipment like smartphones, where internal and external components are coated to make them hydrophobic, as well as lifestyle products such as footwear, gloves and hats. Working like self-cleaning glass would be disastrous here. The whole point is to keep the water off the substance, not to get it wetter.We are really only just starting to see the applications of the lotus leaf effect come to full fruition. For now it is something of a rarity. Arguably it will become as common for a product to have a protective coating as it for it to be coloured with a dye or paint. Particularly for those of us who live in wet climates like the UK, it is hard to see why you wouldn’t want anything you use outdoors to shrug water off easily. I know there have been plenty of times when I have been worriedly rubbing my phone dry on my shirt that I would have loved the lotus leaf effect to have come to my rescue.Seeing nanotechnology at work in the natural world doesn’t have to help us come up with new products. It could just be a way of understanding better how a remarkable natural phenomenon takes place. In the next article in this series I will be looking at a mystery that was unlocked with a better understanding of nature’s nanotech – but one that also has significant commercial implications. How does a gecko cling on to apparently smooth walls?
Image from Wikipedia

Hunting wild skeuomorphs

A skeuomorph sounds like a baddy on the set of Alien vs Predator, but in reality a skeuomorph is an object or feature that copies the design of, or is made to look like something else. And it's a topic of much soul searching among Apple fans at the moment.
Apple's skeuomorphic podcast app
There are some aspects of skeuomorphism few would question. Functional skeuomorphism is why spreadsheets look like sheets of lined paper accountants used to use, why a word processor is a bit like typing on a piece of paper, or why a button in a computer interface looks like - well - a button.
However the aspect that is causing some concern is a tendency to go beyond function to appearance for appearance sake. This can be a good thing - some kinds of decorative skeuomorphism work well with a computer. So, for instance, brushed aluminium goes well with an iMac. But the problem is with decorative appearance based on non-tech stuff like leather bindings on the address book and calendar, and wooden bookshelves. This can look just naff.
This isn't a new problem. I had a US made tape player and games console in the 1970s both of which had plastic fake wood finish - it looked terrible, and I could never understand why they did it, but I assume it appealed to the US consumer.
I think if Apple is sensible they will listen to the growing groundswell against this retro skeuomorphism and at the very least give the option of switching it off. After all, I even saw an article the other day that suggested that Microsoft now has better taste than Apple - surely a call to arms.
I think it's very sensible for an address book to have some address book like layout options, or business-card like displays, but please drop the phoney leather and wood surrounds, Apple.
At the top of this piece is an illustration of another example of this concept. Apple's relatively new podcast app for the iPhone has a design based on a reel-to-reel tape player. This one I have mixed feelings about. At least it is tech, if old tech - so it's not quite so painful. In fact I find it quite sweet. But I don't think anyone can defend faux leather and wood. Get a grip, guys!

Universe Inside You on offer

Sorry, not really a post, more a shriek of excitement, but I had to mention that the Universe Inside You is on the same 24 hour Kindle offer that took Inflight Science up with the likes of 50 Shades of Grey.

Today (Saturday 21 June) it's 99p from the UK Kindle store and $1.54 from the US Kindle store.

When I last looked was #63 on the paid Kindle list: hope to get it all the way! Please spread the word...

Here's a bit about it:


Built from the debris of exploding stars that floated through space for billions of years, home to a zoo of tiny aliens, and controlled by a brain with more possible connections than there are atoms in the universe, the human body is the most incredible thing in existence.

In the sequel to his bestselling Inflight Science, Brian explores mitochondria, in-cell powerhouses which are thought to have once been separate creatures; how your eyes are quantum traps, consuming photons of light from the night sky that have travelled for millions of years; your many senses, which include the ability to detect warps in space and time, and why meeting an attractive person can turn you into a gibbering idiot. Find out more at the book’s website.

Bursting with eye-popping facts and the latest mind-bending theories, the book takes you on journey through the mind-boggling science of the human body:
Every atom in your body was either produced in the Big Bang 13.7 billion years ago or made in a star between seven and twelve billion years ago
Your body contains around 10 times as many bacterial cells as it does human cells
When you make a decision to do something your brain fires up about 1/3 of a second before you are consciously aware of making the decision.

The Baywatch principle

Science isn't always great at naming things. For every photon there are plenty of clunky names that don't do a lot for you. Take, for instance,  the 'principle of least action', which sounds like a description of the lives of teenagers. This is a shame because it is really interesting. For reasons that will become clear I like to think of it as 'the Baywatch Principle.' And what it says, in essence, is that nature is lazy.

French mathematician Pierre de Fermat used the principle of least action to explain why light bends as it moves from a thinner to a thicker substance (from air to glass, for instance) – and Richard Feynman made it a fundamental part of quantum electrodynamics.

The principle of least action describes why a basketball follows a particular route through space on its way to the basket. It rises and falls along the path that keeps the difference between the ball’s kinetic energy (the energy that makes it move) and potential energy (the energy that gravity gives it by pulling it downwards) to a minimum. Kinetic energy increases as the ball goes faster and decreases as it slows. Potential energy goes up as the ball gets higher in the air and reduces as it falls. The principle of least action establishes a balance between the two.

This principle is applied to light by considering time. The principle of least time says that light takes the quickest route. Fermat had to make two assumptions – that light’s speed isn’t infinite (the speed of light was yet to be measured in 1661 when Fermat produced this result), and that light moves slower in a dense material like glass than it does in air. We are used to straight lines being the quickest route between any two points – but that assumes that everything remains the same on the journey. In the case of light going from air to glass, bending is the quickest route. To see why this is the case, compare the light’s journey to a lifeguard, rescuing someone drowning in the sea. The obvious route is to head straight for the drowning person. But the lifeguard can run much faster on the beach than in the water. By heading away from the victim, taking a longer path on the sand, then bending inwards and taking a more direct path in the water, the lifeguard gets there quicker.

Similarly, a light ray can reduce its journey time by spending longer in air and less time in glass. The angle that minimizes the journey time is the one that actually occurs.

When Richard Feynman was inspired by the principle of least action to come up with quantum electrodynamics, the theory that describes the interaction of light and matter so brilliantly, he imagined not just the one “best” path but every single possible path a particle could take in getting from A to B. At the heart of QED is the idea that you can identify the particles behaviour by taking a sum of every single possible path combined with the probability of that path occurring.