Emergent properties

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Perhaps my strongest memory of being taught at school is that of the head of chemistry combining hydrogen and oxygen using an old glass drinks bottle and a burning taper. The result was explosive, exciting and memorable. It certainly engaged the attention of everyone in the class. As far as I am aware, the demonstration was performed at least once per year for decades; but modern health and safety regulations would probably prevent such a demonstration today.

One of the interesting things about combining these two gases at room temperature is that the result is a liquid: water. This could be construed as an emergent property because an examination of the properties of water would not lead you to predict that it was formed from two gases. The philosopher C.D. Broad (1887-1971) coined the term ’emergent properties’ for those properties that emerge at a certain level of complexity but do not exist at lower levels.

Perhaps a better example of emergent properties is the pressure and temperature of steam. We know that water molecules in a cloud of steam are whizzing around randomly,bouncing into one another and the walls of the container – this is the kinetic theory of gases. If we add energy to the steam, for instance by heating it, then the molecules will gain kinetic energy and move around more quickly. The properties of pressure and temperature emerge when we zoom out from the molecules and consider the system of the steam in a container. The temperature of the steam is a measure of the average kinetic energy of the molecules and the pressure is the average force with which the molecules hit the walls of the container.

Manuel Delanda takes these ideas further in a brilliant description of modelling a thunderstorm in his book Philosophy and Simulation: The Emergence of Synthetic Reason. There are no equations and it is written for the layman so don’t be put off by the title. He explains that emergent properties can be established by elucidating the mechanisms that produce them at one scale and then these emergent properties become the components of a phenomenon at a much larger scale. This allows engineers to construct models that take for granted the existence of emergent properties at one scale to explain behaviour at another, so for example we don’t need to model molecular movement to predict heat transfer. This is termed ‘mechanism-independence’.

Ok, that’s deep enough for one post! Except to mention that Capri & Luisi have proposed that life is an emergent property that is not present in the constituent parts of living things and which only appears when the parts are assembled. Of course, it also disappears when you disassemble a living system, i.e. dissect it.

Sources:

Chapter 1 ‘The Storm in the Computer’ in Philosophy and Simulation: The Emergence of Synthetic Reason by Manuel Delanda, published by Continuum, London, 2011 (pages 7-21).

Fritjof Capra and Luigi Luisi, The Systems View of Life: A Unifying Vision, Cambridge University Press, 2014.

Pope and Austen

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A few weeks ago we visited the Marks of Genius exhibition in the recently refurbished Weston Library which is part of the Bodleian Library in Oxford. It is a remarkable exhibition with an overwhelming collection of riches in terms of manuscripts and rare books. You might expect to see a copy of Philosophiae Naturalis Principia Mathematica by Sir Isaac Newton. But one of the items that bowled me over was the original manuscript of ‘An Essay on Criticism’ written in Alexander Pope’s own hand and used by the printer to prepare the first edition in 1711. It was open at the first page and you could see Pope’s annotations and corrections. Pope instructed the printer to put the following lines at the top of the second page:

Tis with our judgments as our watches, none

Go just alike, yet each believes his own

I think he would be astonished at our ability today, not only to believe but, to publish our judgments in blogs. We might have the technology to synchronise our time-keeping devices, whether they are watches or smart phones, but there is still a huge diversity of opinions.

The other item in the exhibition that fascinated me was an unpublished manuscript by Jane Austen of a novel called ‘The Watsons‘. It is tempting to think that the prose written by great authors flows effortlessly onto the page. However, this was clearly not the case for Jane Austen as can be seen from the many crossings out and insertions in this handwritten manuscript. It should perhaps encourage my students who frequently have reports and manuscripts returned to them containing a similar level of my deletions and additions [see my post entitled ‘Reader, Reader, Reader‘ on April 15th, 2015].

The Bodleian Library has digitised the entire exhibition so you can see exactly what I have written about above by following the links to their website:

Alexander Pope’s manuscript

Jane Austen’s The Watsons manuscript

Where science meets society

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Harley_Davidson first electric motorcycle [http://www.harley-davidson.com/content/h-d/en_US/home/motorcycles/project-livewire.html#gallery]

Harley-Davidson’s first electric motorcycle

‘Where scientific advances impact on the health, wealth and well-being of individuals’ is a longer version but I like the pithy version in my title: ‘Where science meets society’. They are both descriptions of engineering. Not the dictionary-style definition of my earlier post [‘Skilled in ingenuity‘ on August 19th, 2015] but a much better tag line to go with those discussed in ‘Engineers sustain society‘ on May 27th, 2015.

Engineers design, build and maintain systems that deliver capabilities. Society and individuals are usually not interested in the system just the capability, unless the system is particular aesthetic or advertising creates the need to own something, i.e. the system becomes a fashion accessory. Consumers are usually more interested in the reliability and life expectancy of the system, or in other words, they would like the absolute certainty that the capability will be available whenever and for as long as it is required. This expectation is problematic for engineers because nothing is certain and entropic degradation ensures nothing remains the same forever. Creative thinking is needed to generate elegant solutions that are cheaper than those of your competitors and this should ensure that engineers are never replaced by artificial intelligence [see my post entitled ‘Engineers are slow, error-prone…‘ on April 29th, 2015]. Engineering might not be a job for life, because nothing is certain, but a bright future, at least until consumers become post-modernists with a tolerance of uncertainty and ambiguity.

Sources:

Thumbnail: http://www.harley-davidson.com/content/h-d/en_US/home/motorcycles/project-livewire.html#gallery

Take a walk on the wild side

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Last month I extolled the virtues of ‘mind-wandering’ (see also the original posting entitled ‘Mind-wandering’ September 3rd, 2014) and I have written in the past about the benefits of taking short walks to improve creative thinking (see my post entitled ‘The Charismatic Engineer‘ on June 4th, 2014). Recent research by Greg Bateman and his colleagues at Stanford has shown it is better for your mental health to take those walks in the countryside. Walking in a natural environment reduces rumination more effectively than in an urban environment. Rumination is repetitive, negative and self-critical thinking that is often damaging to mental health. Of course, this will not be news to many outdoor enthusiasts and ‘pastoral crazes’ are not new. Helen MacDonald has described how in 1930s people used to enjoy long walks in the countryside, including moonlit rambles. For instance, in 1932 the Southern Railway Company offered an excursion to a moonlit walk along the South Downs in England. They expected to sell three or four dozen tickets but one and half thousand people showed up. This 1930s pastoral craze was described by Jed Esty as ‘one element in a wider movement of national cultural salvage’ following the economic disaster of the Great Depression and the instabilities in Europe. Maybe it’s time for train companies to offer moonlit excursions again?