Tag Archives: bees

Letting the grass grow while learning some engineering

Photograph of ATCO 17-inch petrol lawnmower in a gardenLast month was #NoMowMay during which we were encouraged to let the grass grow and allow bees, butterflies and other wildlife to thrive unmolested by your lawnmower.  Our townhouse in the centre of Liverpool does not have enough space for a lawn so I have not mown a lawn since we moved here from the USA nearly a decade ago.  In the USA we followed the convention and maintained our front lawn as manicured green carpet by watering daily, mowing weekly and feeding it monthly during the summer.  An automatic sprinkler system looked after the watering and a lawn service provided monthly doses of chemicals; however, we walked up and down behind the lawnmower each week.  Much to my disappointment, our garden was not really large enough to justify a garden tractor or sit-on mower which has been a dream since I learnt my first self-taught engineering by ‘repairing’ my father’s green ATCO lawnmower when I was about 10 or 12.  I was not allowed lift the bonnet or hood of the family car; and so as the only other piece of mechanical engineering in the garage that has an engine, the lawnmower became the focus of my attention.  I suspect that old lawnmower did not run any better as a result of my ministrations but I certainly understood how an internal combustion engine worked by the time I went to university.  I am an enthusiastic supporter of letting the grass grow, perhaps with a mown pathway so that the lawnmower has to be re-assembled periodically by whichever budding engineer has dismantled your lawnmower.

Source: Joy Lo Dico, How the lawn became a no-mow area, FT Weekend, 29/30 May 2021.

Image: An ATCO 17-inch petrol lawnmower similar to the one mentioned above, from http://www.lawnmowersshop.co.uk/atco-17-inch-self-propelled-petrol-lawnmower-b17.htm

No closed systems in nature

WP_20150722_008 (2)While I was away on vacation last month, WordPress sent an email congratulating me on the third anniversary of the start of this blog.  This stimulated me to look at the statistics on the most frequently read, or at least viewed, of the approximately 160 postings that I have written.  Top of the list is an early posting which asks the question ‘Are there any closed systems in nature?’ (see post entitled ‘Closed systems in Nature?’ on December 21st, 2012).  Since this question has generated more interest than any of my subsequent postings, it seems appropriate, after 30 months, to attempt an answer.

Alexander Bogdanov (1873-1928), and independently Karl Ludwig von Bertalanffy (1901-1972), recognized that all living systems are open systems in the thermodynamic sense, which operate far-from equilibrium and require a continual flux of matter and energy to sustain life.  By contrast, closed thermodynamic systems tend to settle into a state of equilibrium, i.e. with no differences in energy, no chemical reactions in progress and no unbalanced forces.

The cybernetist, William Ross Ashby (1903-1972) suggested that living systems are energetically open but operationally closed, i.e. closed to information and control.  In other words, a cell, or any other living organism, needs no information from the environment to be itself. All the information for a bee to be a bee is contained inside a bee (for more on the bee theme see ‘Entropy management for bees and flights‘ on November 5th, 2014 and ‘Fields of flowers’ on July 8th, 2015).  These concepts, of being energetically open and operationally closed, form the essence of the characteristics of biological life as described by Capra and Luisi, whom I have loosely quoted in the previous sentence.

So, to answer my original question, there are no closed living systems in nature.  We can take this a step further: in 1927  Charles Elton defined an ecosystem in terms of the flow of energy and matter from one organism to another. Consequently, the only waste generated by an ecosystem as a whole is the entropy associated with respiration, which allows the system to satisfy the second law of thermodynamics, and the waste is replaced with energy from the sun through photosynthesis.  The sum of all ecosystems is the biosphere.  So, it can be construed that everything on Earth is part of one giant open system – this is essentially the Gaia hypothesis.


Gorelik, G., Principal ideas of Bogdanov’s tektology: the universal science of organisation, General Systems, 20:3-13, 1975.

Bertalanffy, L. von, General Systems Theory, New York: Braziller, 1968.

Ashby, W.R., Design for a Brain, New York: Wiley, 1952.

Capra, F., Luisi, P.L., The Systems View of Life – A unifying vision, Cambridge: Cambridge University Press, 2014.

Elton, C.S, Animal Ecology, London: Sidgwick & Jackson, 1927 (reprinted 2001, University of Chicago Press).

Lovelock, J., Gaia, Oxford: Oxford University Press, 1979.



Fields of flowers

It’s not often that someone presents you with a completely new way of looking at the world around us but that’s what Dr Gregory Sutton did a few weeks ago at a Royal Society Regional Networking Event in Bristol where he is a University Research Fellow funded by the Royal Society. He told us that every flower is a conductor sticking out of the ground which on a sunny day has an electric field around it of the order of 100 volts per metre. Bees can identify the type of flower that they are approaching based on the interaction between this field and the electrostatic field generated around them as they fly. Bees are covered in tiny hairs and he believes that they use these to sense the electric field around them. The next research question that he is tackling is how bees are affected by the anthropogenic electric fields from power lines, mobile phones etc.

The plots of the electric field around a flower really caught my attention. You can see one in the thumbnail photo. I walked across Brandon Hill in Bristol after the talk to meet a former PhD student for dinner. I kept stopping on the way to try to detect this field with the hairs on the back of my hand. It was a beautiful sunny day but I was not sensitive enough to feel anything. Or maybe I was sensing it but my brain is not programmed to recognise the sensation. We discussed it over dinner and marvelled at the bees’ ability to process the information from its multiple sensors in the light of our knowledge of the computing power required to handle what it is fashionable to call ‘Big Data’ from man-made sensors.

Once again Nature humbles us with its ingenuity and makes our efforts look clumsy if not feeble. Dr Sutton’s insights have given me a whole new way to attempt to connect with Nature while I am on deep vacation.

Sorry about the pun in the title. I couldn’t resist it.


Clarke D, Whitney H, Sutton G & Robert D, Detection and Learning of Floral Electric Fields by Bumblebee, Science, 5 April 2013: 66-69. [DOI:10.1126/science.1230883].

Entropy management for bees and flights

entropy_vectorEngineers like to apply the second law of thermodynamics to chemical processes and power generation cycles. However, it has some useful lessons for everyday life since it can be paraphrased as ‘whenever you organise any process expect some disorder, or entropy to be generated’, so a shrewd person plans for disorder and designs in a bit of slack or redundancy.

Bob and I gave an example of this in our book, ‘The Entropy Vector’.  We pointed out that if you plan your flight schedule to use all of the available gates at an airport then you will have unhappy passengers when flights are delayed, unless you plan for buses to unload planes parked away from the terminal. European airports tend to be good at this whereas US ones tend to leave passengers in planes that are unable to dock at the terminal.

Our example was inspired by frustrating experiences when we were writing the book. A more topical and important example was raised by Mark Winston in the New York Times on July 14th, 2014 in reporting the importance of bees to farming. His research team found that crop yields were maximised when large acreages were left uncultivated to support wild pollinators. He postulated that a variety of wild plants means a healthier, more diverse bee population which will be more active in the planted fields next door. Their numbers were startling with profits more than doubling for farmers that left a third of their acreage fallow. Winston highlights that this contravenes conventional wisdom that bees and fields can be micromanaged.

This seems like reinventing the wheel because I remember being taught about the importance of crop rotation, including a fallow period, in my ‘middle’ school geography classes. Oh dear, now I am showing my age.

The bottom-line is don’t micromanage. Allow for a bit of inefficiency, not too much of course or your competitors will get ahead! It’s a question of balance.