Tag: science

Lasers go oooooommmmmmm

In a previous post I mentioned, in passing, surface quasi-elastic light scattering (SQELS). SQELS is a fancy way of measuring the surface tension of a liquid using light, it has some advantages over the alternative method: sticking something into the surface of the liquid and measuring the pull but it is technically challenging to do.

The basic idea of SQELS is this: if you take a liquid surface, even in the absence of breezes or shakes, it is perturbed by tiny waves the properties of which tell you about the surface properties of the liquid. These waves have frequencies of 10kHz, wavelengths of 0.1mm and amplitudes of only a few angstroms. They are driven by the thermal motion that means everything, on a small enough scale, is jiggling away incessantly. To measure these waves laser light is shone on the surface, most of the light is scattered elastically that’s to say it stays exactly the same colour. However, some of the light is scattered inelastically (or quasi-elastically since the effect is small) – it changes colour slightly, the power spectrum of the surface waves is imprinted onto the laser light in terms of shifts in its colour. So all we need to do is measure the power spectrum of the light reflected from the surface to find out about the surface properties of the liquid.

It turns out I don’t have any photos of the SQELS apparatus in all its glory, so I shall describe it in words. The whole thing is found on an 8 foot by 4 foot by 1 foot thick optical table. A fine, very solid table whose top surface is a sheet of brushed steel, pierced by a grid of threaded holes 25mm apart. The apparatus is in the form of a large U covering two long sides and one short side of the table. A laser is bolted at the start of the U; light heads from the laser along the table through a set of lenses, polarisers, a diffraction grating, then upwards through a periscope before being directed down onto the liquid in Langmuir trough. The Langmuir trough is protected by a cardboard box, decorated in the style of a Freisian cow with holes cut roughly in the sides to allow light in and out. Captured after reflection from the surface of the liquid, the laser light is directed back down to the table surface by a second periscope from where it passes back along the long side of the table into a photomultiplier tube – the detector.

The cardboard box is there to stop air currents disturbing the surface of the liquid, vibration is the enemy for this experiment because the liquid in the Langmuir trough picks up the slightest disturbance and wobbles around. Sitting on an optical table weighing a large fraction of a tonne isn’t enough – it needs to be on the ground floor too because buildings wobble and in this instance the Langmuir trough sat on an active anti-vibration table – a bit like noise cancellation headphones but the size of a small coffee table. You can manage without active anti-vibration if you’re willing to do your experiments in the dead of night.

The cardboard box is emblematic of a piece of research apparatus: much of it is constructed from pre-fabricated components, some of it is custom-made in the departmental workshop but then there are the finishing touches that depend on your ingenuity and black masking tape. I did have plans to get the cardboard box remade in perspex but the box was just the right size and if I wanted more holes in it I could easily cut them with a knife so it was never worth the effort. I seem to remember a bit of drainpipe being involved too. As an experimental scientist you get your eye tuned in to spot things just right to add to your apparatus.

The laser is a single mode solid-state laser producing light of 532nm wavelength – a brilliant green colour. Three things are important about lasers: firstly, they are fantastically bright; secondly, they produce light of a very pure colour – a single wavelength. Thirdly, lasers go “oooooooommmmmmmmm”, whilst conventional light-sources go “pip-pip—-pip-pip—pip”. Technically this is described as “coherence”, we’re using a laser in part because we want something to compare against and a conventional light-source isn’t going to work for this. If you’re measuring a small change, it’s very handy to have a “ruler” close at hand, and in this case the elastically scattered light is that ruler.

You’ll notice that I’ve not said anything about the results we obtained using the SQELS; truth be told, despite all the hours spent building the apparatus, doing the experiments and analysing the data the results we obtained told us little more than that which we could get by easier and simpler means that I described in my earlier post. I also had the sneaking suspicion that it would have helped if I knew more about optical engineering.

(I got distracted in the middle of this post, browsing through the Newport optical components catalogue site!)

Reference
Cicuta, P., and I. Hopkinson. “Studies of a weak polyampholyte at the air-buffer interface: The effect of varying pH and ionic strength.” Journal of Chemical Physics 114(19), 2001, 8659-8670. (pdf)

Experiments for obsessive compulsives

It feels like I’ve not really been writing about science very much recently, so I thought I’d return to some work on which I spent a few years, with my former PhD student, Pietro Cicuta.

We looked at the properties of a protein from milk (β-casein) spread on the surface of water: principally the effect that it had on the surface tension as a function of amount of protein. Experimental variables were the acidity and saltiness of the water. We did this using a Langmuir trough which I’ll describe below. b-casein is what’s known as a random coil protein: in contrast to many proteins, which curl up into a well-defined, unique shape, β-casein flops around like a piece of string. This work is directly relevant to people working in the food industry, and more generally interesting to people who work with polymers (chemists) and proteins (biologists).

β-casein acts as a surfactant which helps stabilise fat globules in milk. Surfactants are common type of molecule, the name is a contraction of “surface”, “active” and “agent”, unsurprisingly they are found at surfaces: typically between one liquids, like oil and water, but also at interfaces between liquid and air. Surfaces are important, they keep the inside in, and the outside out. Surfactant molecules help with this important process by stabilising surfaces (the natural tendency of liquids is to form big blobs, surfactants stop this process). Some examples: the cells in your body are surrounded by surfactants, mayonnaise contains surfactants from egg which keep the oil suspended in the water, all manner of cleaning products for clothes, hair, work by using surfactants to stabilise dirt in water, and foams are formed using surfactants.

To achieve this magic surfactants share a common feature: part of the molecule likes oil and part of the molecule likes water, so to keep both parts happy they hang around at interfaces. Most surfactants are like little tadpoles with water-loving heads and water-hating tails. β-casein is a bit different, parts of the string like water, so they try to stick into the water and parts don’t like water so they head for the air. However changing the acidity and saltiness of the water changes the strength of the love for water.

In most cases substances love water because they have an electrical charge, and this is why salinity and aciditiy are important in this experiment: if you change the acidity of the water the electrical charge on the protein changes because of the chemistry of the protein, if you change the salinity then how well the water can see the charges changes. It’s a bit like fog, when there is no salt in the water it’s as if the electric charges are seen through clear air and their influence spreads far and wide, adding salt is like a mist reducing the visibility of charges until ultimately the electric charges can’t be seen at all.

A Langmuir trough is a way of probing surfactant properties. It comprises a shallow trough made of Teflon, a barrier made of Teflon (which can be swept across the surface of liquid in the trough) and a surface tension sensor. Teflon is used because water sits on top of it forming a proud meniscus rather than spreading out, damply. The sensor is nothing more than a bit of filter paper attached to a force measuring device, dip it into the water and feel the pull – that’s surface tension. The idea with the barrier is that you place the barrier at one end of the trough, drop your molecules on the surface and then slide the barrier along, the molecules on the surface have few places to go so the decreasing the area amounts to increasing the concentration of the molecules at the surface. It’s really the 2D version of compressing a gas with a piston. I tried to find a picture of a trough with a single barrier, but couldn’t – the principle of the two-barrier trough shown here is the same, the black tower in the middle is the surface tension sensor.

Langmuir trough experiments are ideal for obsessive-compulsives: before you start your actual experiment you have to get the surface of the liquid you’re using absolutely clean. To do this you clean your trough, add in the ultrapure water, compress the surface, hoover (with a glass pipette connected to a vacuum pump) contaminants off the surface if there was an upturn in the surface tension, then go back to compressing the surface, hoovering the surface etc. Some times it just doesn’t work and you spend a morning trying to get your trough clean. Doing this for an oil/water interface is difficult, much more difficult actually I never succeeded. The core of the problem is that you don’t need much material to make a surface dirty, imagine painting a ball – the amount of paint required to cover the surface is much smaller than the volume of the ball.

The Langmuir trough was developed by Irving Langmuir, building on work by Agnes Pockels done towards the end of the 19th century. You’ll often see references to the Langmuir-Blodgett trough, the two terms seem to be used interchangeably but my understanding is that the Langmuir-Blodgett device is used to deposit surface active molecules onto a surface (which is not what we were doing). The Blodgett is Katherine Blodgett, who was the first woman to be awarded a PhD in Physics from Cambridge University.

From the surface tension data we extracted two things: firstly, how the protein molecules interact with each other – this comes from the early part of the compression data when the molecules are just starting to touch each other. Secondly, we get some idea of the innards of the protein from what happens when we squeeze the molecule harder and it starts to deform. Think of it like a bunch of eggs if you’re bouncing them around in a basket you find out about how bouncy they are, if you grab hold of one and squeeze it really hard you first discover that it has a tough outer shell, then you discover it has a soft squishy inside, then you discover you have egg all over your hands and you forgot to get the kitchen towel out before you started.

We find out this information about interactions and internal properties as a function of acidity and salinity, which we can then compare with theories of charged polymers. This comparison turned out to work quite nicely, and Pietro came up with a neat way of illustrating how bits of the molecule appeared to plunge into the water as the surface layer was compressed.

This is pretty much my most cited piece of work, with just less than 30 citations. So there you go, several years in the lab condensed into just over a 1000 words, although I didn’t mention the Surface Quasi-elastic Light Scattering (SQELS).

Reference
Cicuta, P., and I. Hopkinson. “Studies of a weak polyampholyte at the air-buffer interface: The effect of varying pH and ionic strength.” Journal of Chemical Physics 114(19), 2001, 8659-8670. (pdf)

Seeing Further: A Blaggers Guide (Part 1)


I originally intended to describe this post as a book review, but really it isn’t. It’s a blagger’s guide for those that haven’t read the book in question, (Seeing Further: The Story of science and the Royal Society edited by Bill Bryson) or who have read it, but need reminding of the contents. If you want to read a proper review then I suggest Clare Dudman’s review at Bookmunch.

Seeing Further is a collection of essays from a wide range of authors, all relating in some way to the Royal Society which celebrates it’s 350th anniversary this year. I’ve read other work by most of the authors – they are all excellent.

Since I’ve written notes on each chapter this has become quite a long post, so I’ve broken it into two parts. Part two can be found here.

Bill Bryson starts things off with an introduction, providing a brief sketch of the history of the Royal Society and introducing a few of the distinguished fellows. His favourite is Reverend Thomas Bayes. Bayes’ most important work was on probabilities, published two years after his death in 1761. Few will have heard of Bayes, but his work is central to modern statistics. I must admit this chapter made me curious as to the origins of other learned societies across Europe.

Then the fun begins with James Gleick, who has written excellent books on chaos and Richard Feynmann amongst many other things. He writes of the Society as an earlier version of the internet and the first place where people started recording and communicating observations systematically. They also conducted their own experiments. The international reach of the Royal Society was an essential component, managed effectively by it’s first Secretary, Henry Oldenburg.  Perhaps wisely the fellows instituted a ban on discussing religion or politics.

Margaret Atwood writes about the development of the idea of the mad scientist as portrayed in the 50’s B-movies. She sees the Royal Society, satirised by Jonathan Swift as the Grand Academy of Lagado in Gulliver’s Travels, as the link between Dr Faustus and the modern mad scientist. Travelling by way of Mary Shelley’s Frankenstein and Robert Louis Stevenson’s Dr Jekyll and Mr Hyde.

These days it is broadly a given amongst scientists that the physical laws they determine here on earth extend throughout the cosmos. Margaret Wertheim writes on the genesis of this idea, the point when the boundary between heaven and earth was removed in mens minds and the heavens and earth started to be considered as a continuous whole, obeying the same physical laws. This transition had largely taken place prior to the formation of the Royal Society.

Neal Stephenson writes on Gottfried Leibniz and his monads. Stephenson is author of The Baroque Cycle, a historical science-fiction trilogy set around the time of the founding of the Royal Society with many of the early fellows featuring as characters. Monadology was Leibniz’s philosophical program for understanding the universe, looked at with a modern eye one can see intriguing insights but ultimately our current understanding of the universe is quite distant from Leibniz’s conception of monads. Nowadays it’s recognised that Leibniz and Newton invented calculus independently and simultaneously, although Leibniz published first. The priority in this area was greatly disputed, with the Royal Society standing firmly behind Newton, latterly their President.

Next up is Rebecca Newberger Goldstein on how the establishment of the Royal Society marked the coming together of the rationalists, whom we would probably call theoreticians now, and the empiricists, or experimentalist in modern parlance. Contrasting these two more modern movements with the teleologists of ancient Greece who believed that the world was designed with a purpose and so their philosophical program was to identify the purpose of all things and the progress of those things towards their final ends. Although the teleologists observed, they tended to do so passively whilst the empiricists actively experimented: setting up nature to reveal underlying processes. The immediate precursors to the Royal Society were represented by empiricists such as  Francis Bacon, William Gilbert, and William Harvey and the rationalists represented by Nicolaus Copernicus, Johannes Kepler, Galileo Galilei and Rene Descartes. John Locke, Isaac Newton and Robert Boyle are cited as those at the forefront of the debate on what constitutes an explanation during the forming of the Royal Society.

Now for Simon Schaffer who tells a tell about the use of scientific advice for public policy development, and public dispute over that advice. The story is set around the tale of a lightning strike in Norfolk which struck the Heckingham House of Industry (a workhouse) on 12 June 1781, causing substantial damage. The building was protected by pointy lightning rods, as recommended by the Royal Society and the tale is of much internal bickering as to whether the lightning rods had been installed properly or whether the advice given by the Society was wrong. This was highly relevant at the time since, for example, you’d want to be really sure of your lightning protection if you ran an arsenal, full of gunpowder. Also interesting is who the fellows of the Royal Society trusted to give eye-witness statements: gentleman! Schaffer never really resolves the issue of the accuracy of the advice but highlights the parallels of this argument with modern arguments about evidence-based policy and how best to make recommendations based on science.

We move on to Richard Holmes, who writes about ballomania. This is the name coined by Sir Joseph Banks, recent president of the Royal Society, for the enthusiasm in France for balloons of both hydrogen and hot air during the 1780’s. Outwardly Banks was dismissive of balloons, but in private he appears to have been keeping a close eye on developments. Ultimately the lack of navigability meant that interest in balloons waned. This chapter reminded me that Benjamin Franklin is someone of whom I need to know more, Franklin was Banks’ correspondent in Paris where much of the balloon-y action was based. Another snippet, Aeropaedia, published 1786 records a balloon flight from my now home-town of Chester. Richard Holmes is the author of The Age of Wonder, on which I wrote earlier.

Richard Fortey is up next, author of Dry Store Room No. 1, which is about the Natural History Museum, given this background it’s unsurprising that he writes about scientific collections. Well-curated collections of real objects are of critical importance to science. Fortey’s chapter explains the role that the Royal Society played in setting up such collections, principally through the work of Sir Hans Sloane, a president of the society, whose collection was to form the basis of the Natural History museum via the British Museum. Sir Joseph Banks makes an appearance, for his work in setting up the Royal Botanical Gardens at Kew, as does Carl Linaeus father of taxonomy.

Richard Dawkins, who needs no introduction, writes on the claims for precedence in the discovery of evolution. It’s relatively well-known that Alfred Russell Wallace spurred Charles Darwin into action by sending a manuscript to him which captured the core idea of evolution. Darwin’s great achievement was the full length exposition of the theory, backed with experiments, in On the Origin of Species. Perhaps less well known are Edward Blyth, who believed that natural selection stabilised those species created by God (which is not really evolution) and Patrick Matthew, who mentions an idea of evolution quite similar to Darwin in the appendix of his book Naval Timber and Arboriculture but seems to have little idea of its significance.

Here endeth the first part of this review, feel free to get up and move around, perhaps have a cake and a coffee. Then move on to Part 2.

Seeing Further: A Blagger’s Guide (Part 2)

My writings on Seeing Further: The Story of Science and the Royal Society became unmanageably long, so I have split it into two parts, this is the second part, the first part can be found here.

In the earlier chapters there was much philosophy and history. Henry Petroski writes on bridges, which I must admit surprised me a little as an area of interest for the Royal Society but the link is there. When Robert Stephenson proposed the design for the original Britannia Bridge it was William Fairbairn, soon to become a fellow of the Royal Society, who carried out experiment studies to establish the shape of the iron box-sections. This was done by testing the strength of scale models, and progressively increasing the size of the models – extrapolating the results to the full-size bridge. Later he went on to investigate metal fatigue, which had led to several serious rail disasters in the 19th century.

We’re heading into living memory now, with Georgina Ferry’s chapter on structural biology through the medium of x-ray crystallography. A field in which Britain led the world in the middle of the 20th century. This period sees the election of the first female fellow of the Royal Society, Kathleen Lonsdale, in 1945, who made some of the first determinations, by crystallography, of the structure of small molecules. Following this Dorothy Hodgkin determined the structure of penicillin in secret work during World War II. This type of investigation reached a climax with the determination of the structures of first proteins, massive efforts taking Hodgkin 35 years for insulin and Max Perutz taking 22 years for haemoglobin. Georgina Ferry’s biography of Dorothy Hodgkin is well worth a read and covers in more depth much of the material in this chapter.

Steve Jones, geneticist, provides a chapter on biodiversity. We believe that evolution provides a good explanation of how species arise and change over time. The subject of biodiversity addresses the question: how many species can we expect to find in a particular environment? And the answer is we don’t really know,  there don’t seem to be any rules that allow us to predict biodiversity. There are some observations, such as biodiversity is greater in the tropics than elsewhere but no real understanding of why this might be.

C.P. Snow wrote about the two cultures, what is less well reported are his comments on the gulf between “pure” sciences and applied sciences. Philip Ball expands on this theme, and makes a plea for a better appreciation of the engineers and technologists, under whose aegis much essentially scientific work is done. One of his examples are plastics (or polymers), the field in which I am trained.

Paul Davies asks how special are we? In cosmology we hew to the Copernican Principle, the idea that there’s nothing special about earth, nor the sun nor even the galaxy we find ourselves in: if we look around the universe we expect to find planets, suns, galaxies just like our own. It is only when we enter the highly speculative area of the multiverse that this part of the Copernican Principle starts to break down. Related to this questions is the more open one of “Are we, intelligent life forms, special?”. We simply don’t know whether life, or intelligent life is common in the universe.

I hope you’re not getting bored of this machine gun delivery of chapter synopses!

Ian Stewart writes on the importance of mathematics, often hidden from view even to those in the know. He uses the example of the recent Mars missions, which fairly evidently use the mathematics of Isaac Newton (a fellow of the Royal Society), but less obviously the work of George Boole (another fellow living 1815-1864). Boole is responsible for providing the foundations of modern computing through his Boolean logic – the ones and zeros on which computers thrive. Compression and error-correction algorithms also make heavy but invisible use of mathematics. JPEG compression, in particular, uses the work of, foreign member of the Royal Society, Joseph Fourier (1768-1830).

John D. Barrow is up next, he is a cosmologist. He starts off explaining the underlying simplicity of physical laws, and the attempts to unify the theories of different forces into a single “Theory of Everything”. The current best candidate for this theory of everything is string theory. He then discusses chaos and complexity: simple laws do not lead to simple outcomes. The behaviour of a pile of sand is not easy to predict.

The next three chapters have a a slight theme running through them. Oliver Morton starts off with the “blue marble” image captured from Apollo 17. This demonstrates, self-evidently, the spherical nature of the earth but beyond this it implies an isolation and stasis. There is little evidence of movement, or process taking place. Morton’s point is that the Earth is not a static system: light from the sun enters and great cycles turn over carbon, nitrogen and water in the system, taking these chemicals through the earth and the sky. This leads into thinking about climate change.

Maggie Gee starts off by introducing about apocalyptic writing, fiction about the end of the world (or at least after a great disaster). Gee is an author of such fiction, including The Flood and The Burning Book. I must admit I’ve always seen this as a genre that doesn’t really ask me to contemplate my own end, but rather selfishly imagine my survival in the aftermath. After this introduction she then moves on to discuss global warming and the part that writers might play in it’s communication. I found this a very interesting perspective. Most of the authors in this volume I’ve read before, Maggie Gee is one I haven’t read but aim to address this lack.

Continuing the global warming theme, Stephen H. Schneider is a climate scientist who has long been involved in the the Intergovernmental Panel on Climate Change (IPCC), as an normal author in the first two reports and a lead author in the second two reports. In this chapter he talks about introducing standardised language to describe uncertainty into the fourth assessment report, known as AR4. There is a clear need to do this because if the scientists writing the report don’t communicate their assessments of uncertainty then others, less-qualified, will do it for them. It’s not that uncertainty was unrecognised in previous reports, but it’s communication was not clear. Schneider was involved in preparing clear advice in this area. Persuading scientists to use well-defined language to communicate uncertainty seems to have been a battle.

Gregory Benford talks about time, firstly he talks about the Deep Time discovered in the 19th century by geologists such as Charles Lyell FRS. This was the realisation that the earth had been around rather longer that the few thousand years that a literal reading of the bible suggested. This change in thinking was based on an assumption that the changes in landscape seen in the present were largely all that was required to create the landscape, this is in contrast to the prevailing view of the time based on cataclysms like the biblical Flood. Also, Darwin was of the view that evolution would have required hundreds of millions of years to lead to the diversity of species seen today.  The great age of the earth was subsequently confirmed using radioactive decay measurements. Also discussed is time and it’s merging into space which is central to Einstein’s general theory of relativity. Benford is a scientist and science-fiction writer, I can recommend Cosm, a story about physicists who create a universe in a particle accelerator and drive it off in a pickup truck.

And finishing off with a chapter by Lord Rees, the current President of the Royal Society. Rees looks forward  to discoveries in the next 50 years; at various times in the past people have claimed we are coming to the end of science. Rees points out that each new discovery opens up new areas, so feels there’s no risk of us running out of science to do. He also writes of the continuing role of scientists as advisers, a task that the Royal Society continues to coordinate and drive. And the finally on moral responsibilities of scientists, on which I wrote a little previously with regard to the atomic bomb.

All in all I found this a very enjoyable read, some of the philosophical and literary chapters I would not have read as full length treatments but enjoyed in shorter form. The links to the Royal Society are tenuous in many of the chapters, so perhaps it’s best to approach this book as a sampler for fine science writing.

The Green Scientist


This week I’m writing about my attitude to some green issues, and how I think my scientific background informs my approach. The reason I’m doing this is that when discussing green issues, it becomes obvious that I have some very different starting points compared to non-scientists. I can describe my own views, and I believe various of them are shared by other scientists for similar reasons. And it might get a little bit ranty.

First of all, I really like the idea of sustainability: the idea that after our lives we leave the earth in broadly the same state as we found it so that those that follow us have something to live on. I believe we should be trying to preserve our natural environment and the species in them, even the unattractive ones. How we achieve sustainability, and what we actually focus on are the areas of collision.

And so to “Chemicals”: “Chemicals” which are always bad and must be excluded from things. From a scientific point of view this is frustrating: all things are chemicals – atoms joined up together. Even if we’re slightly more sophisticated and claim that natural chemicals are good, and man-made chemicals are bad, we’re still on tricky ground. Anyone for strychnine, belladonna or ricin? Really we can only say “good chemical”, “bad chemical” by looking at the chemical in question. There is a Romantic view abroad that nature favours us and wishes to provide us with nice things: this simply isn’t true. At best nature is indifferent, and in many cases it is actively out to get us.

There’s a biological variant of this stance, in genetically modified organisms (GMO). I think there’s real potential for GMO’s in sustainable agriculture, but it is excluded for essentially ideological grounds and with ideological fervour. Misplaced genes can certainly be a problem but much more likely when introduced en bloc in introduced organisms (rabbits in Australia, rats in almost any island environment, Himalayan Balsam in UK), and we’re surprisingly tolerant of crops that are toxic if prepared inappropriately (potatoes, rhubarb, red kidney beans, cassava). We’re in the bizarre situation where one group can complain of the contamination of the genetic purity of their crops by GMO’s for which there is no evidence of harm, and no expectation of harm. Where the detection of the contamination takes rather sophisticated scientific techniques. And beyond that even people are getting agitated by the thought of eating cattle fed with GMO’s, when we have no way of detecting whether the cattle have eaten the GMO – there is no measurable effect.

The image at the top of this post is another example, I found it buy searching for “belching-pollution” it’s the type of image you often see illustrating a story about pollution but those are cooling towers, the stuff coming out of them is water vapour – clouds. Not pollution at all.

The Food Programme on Radio 4 irritates me every week, and I really like my food. A typical script runs roughly like this:

Supermarkets are bad, lets do a taste test. Here’s Mrs Miggin’s hand-knitted pie, with Mrs Miggins who we’ve been talking to for the last 10 minutes, here’s a supermarket pie, doesn’t it look nasty? I don’t think I want to eat that. Let’s try them both, well Mrs Miggins pie is lovely, but I really didn’t like the supermarket pie. The supermarkets are evil. What’s that you say? “Mrs Miggins pie costs 5 times as much as the supermarket pie”. Well I’m sure that isn’t important.

I think I drifted off the point slightly with that last bit of rant, but it reveals something of my character. I’m actually in favour of people that do stuff, rather than the people that stand on the sidelines complaining that they’re doing it wrong but don’t really proffer a workable solution.

Much of the problem here seems to be an elision over scientific issues and capitalism / globalisation. GMO’s largely became “bad” because they were developed by very large corporations for reasons of profit. I don’t see large companies as intrinsically malign, I see them responding to a set of circumstances which makes them appear malign. The trick for society is to make an environment that makes companies to act for our collective good because it’s in their best interest to do so.

So there you are: I’m a frustrated green, I sign up to the principles but the implementation offends my scientific sensibilities. In a timely fashion, it would appear I’m not alone – see this interview with Stewart Brand in New Scientist.

Thank you for hearing my rant.