Month: April 2013

Good enough

Last week I stayed at the Goodenough Club in London while teaching part of a workshop on ‘Engaging Engineering Students in the Classroom’.  The Club provides accommodation for university staff and students visiting London and is attached to Goodenough College, which was founded by Sir Frederick Goodenough in 1930 to provide a collegiate residence and educational trust for international students.  It is located in a leafy square near Coram’s Field and is a tranquil environment to stay in the centre of London.

The name of the College and Club stimulated me to think about the concept of Good Enough or something that is satisfactory or sufficient without excelling.  The concept of sufficiency is one that needs to be closely connected to sustainability because to achieve sustainability we need to remove any tendency towards excess, since excess simply leads to a waste of the Earth’s finite resources [see my post on an ‘Open-world Mind-set’, 4th January, 2013].  As a society we are not very good at sufficiency or good enough.  Businesses and politicians sell us the idea that growth in the quantity and value of our material possessions is a desirable indicator of success so that we tend see self-sufficiency as a somewhat idiosyncratic approach to life.

Never ending growth of material possessions is not viable on a planet with finite resources so if there are to be any resources left for grandchildren then we had better get used to good enough.

Advertisements

Sonic screwdrivers

138-3816_IMG

No relevance except for the tranquility or absence of noise.

In a recent post on Noise Transfer [27th March, 2013] I highlighted the parallels between energy transfer by heat and noise.  In many cases, the heat and, or noise transfer is by-product of a process through which energy is dispersed to satisfy the requirements of the second law of thermodynamics, that entropy must increase as a product of all real processes.  Entropy, can be interpreted as a measure of dispersion, or the lack of availability to do anything useful and this applies to most heat and noise that we encounter in everyday life.

We can use concentrated sources of heat to produce useful work such as the furnace in a power station, but the second law of thermodynamics demands that we waste a substantial proportion of it through the creation of entropy.  It is also possible to use concentrated sources of noise, such as ultrasonic transducer to perform useful work for us, such as in surgery and the manufacture of composite materials [see Professional Engineering, http://profeng.com/features/good-vibrations ]; although an all-purpose sonic screw-driver of the kind used by Dr Who is not possible, yet.

Extraordinary technical intelligence

In his book ‘A History of the World’, Andrew Marr identifies a recurring process in the development of societies, from an agricultural revolution that releases enough people from food production in the countryside to enable basic manufacturing in town and cities, through an industrial revolutions leading to more sophisticated manufacturing and a large, rapid rise in the standards of living.  This process happened first in Britain during the 18th and 19th century, in the US during the 19th and 20th century and then more quickly in Japan, Korea and Taiwan in the second half of the 20th century.  It is happening now and even faster in China with the same ‘grim working conditions in the factories, the raucous enjoyment of plenty by the winners in the cities and a certain recklessness about pollution’ to quote Andrew Marr [Marr, A., A History of the World, MacMillan, 2012].  It is starting in India and Africa might be next, though in the Financial Times on Friday 22nd March, 2013 Chandran Nair argues that we should reverse the flow from the countryside to the cities if we want to achieve a sustainable society.  This might just be possible in Africa, probably not in India and China seems set to follow the well-beaten path to urban industrialisation.

What comes next in the process?  Perhaps a loss of interest in manufacturing industry, followed by over-spending by individuals and governments, economic recession or collapse and stagnation of growth.  Andrew Marr suggests that the wealth based on manufacturing derives from ‘mankind’s extraordinary technical intelligence’ and that there is ‘a long lag in advancing our political and social intelligence’.  The stale-mate at the heart of US politics and the failure of successive UK governments to avert a multi-dip economic recession would suggest the need to advance our political intelligence.  In the meantime we might lose our technical intelligence if don’t train more graduates in technology [see my post on Financial crisis, 27th March, 2013].

Noise transfer

This is not the author's house!

This is not the author’s house!

We are privileged to have magnificent views of the river and mountains beyond from our city centre house.  However, the house was built before the motor car was invented when the loudest event outside might have been rowdy party-goers heading for home.  We still have some party-goers walking home under our bedroom window at night but most of them travel by noisy taxis.  I look forward to when the price of fossil fuels, or legislation will force taxis to become electric-powered.  In the meantime, we have been designing secondary glazing that will offer a high resistance to noise transmission and be in keeping with the early 19th century windows.  Noise is a form of energy transfer by vibrations, acoustic energy would be an alternative term for it, and so the combined resistance of the outside wall of my bedroom can be calculated using Kirchhoff’s law, as discussed for heat transfer in my last post [Born in a barn, 20th March, 2013].  In this case, the thin and badly-fitting but antique glass is the dominant component of both the heat and noise resistance.  We were happy to deal with the poor resistance to heat transfer by using plenty of bedclothes, i.e. adding a large resistance in series, but the same approach does not work with noise because earplugs are uncomfortable, fall out in your sleep and have a low resistance at the frequency of taxi-generated noise.  So, the solution is secondary glazing and the best performance is achieved using an acoustic laminate consisting of a polymer sandwiched between two sheets of glass which should be different thickness to avoid resonant effects.  Of course this will also improve the resistance to heat transfer which will be advantageous in winter, but perhaps not in summer…