Month: February 2015

‘Culture eats strategy for breakfast’

130-3071_IMGMy title is unashamedly borrowed from Richard Plepler, CEO of the premium US cable network, HBO.  He was quoted in an interview reported in the Financial Times on January 11th, 2015 [Lunch with the FT by Matthew Garrahan].  It was said in the context of discussing how a company can encourage creativity.  I like it because it sums up my own approach to nurturing an environment in which high-quality innovative research can flourish.  The role of the leader is to establish and maintain that environment in which everyone must feel able to express their opinions and then once the decision is made be prepared to unite in achieving the goal.  This requires a level of transparency that many leaders find hard to implement and ability to listen to dissenting views that most leaders find difficult or impossible to tolerate. Good leaders create a culture in which people feel safe expressing their views.  To quote Richard Plepler again “Someone once said to me, ‘You made the room safe to talk.’ And I said. ‘If you want to win, what other way is there to be?'”.

Engineering is a creative profession in which we need to worry more about culture and less about strategy.  Of course, bringing about culture change is much harder than writing a new strategy!

Good reads for budding engineers

Photo credit: Tom

Photo credit: Tom

I have been asked to help populate a school library with books that will be of interest to prospective engineers.  I suspect there is a sub-text that it would be good to include books that might stimulate more pupils to consider becoming engineers.  I think this is a hard task and so I am hoping my readers will help me by leaving a comment in the form a personal recommendation.

There are a number of suggested reading lists available, e.g. the one provided by Cambridge University Engineering Department.  However, the feedback that I have had from an enthusiastic budding engineer is not encouraging.  She found all the books she read from these lists to be dull and uninspiring.  So, that’s why I am issuing a challenge this week: find books connected to engineering that under-18s think are interesting!

Please don’t send me a recommendation unless you have actually checked with a teenage that they enjoyed it.

Cosmic heat death

MSUSpartans_Logo.svgWhen I was at Michigan State University, Lou Anna Simon, the President was fond of talking about constructive tension as a source of innovation and progress. In other words, creative or productive work arises out of differences, for instance between aspirations and reality, or between supply and demand.  Rudolf Clausius in the 1850’s identified the irreversibility of heat flow across a temperature difference from hot to cold [see last week’s post on ‘Why is thermodynamics so hard?].  Sadi Carnot worked out the productivity of this difference in terms of the maximum efficiency with which work could be extracted from it [see my post ‘Impossible perfection‘ on June 5th, 2013].

William Thomson [1827-1907] followed a much more sinister line of thought and concluded that if all heat flows from hot to cold then eventually everything must end up at a uniform temperature, i.e. no differences.  He argued that no temperature differences implies no work could be extracted.  And nothing at all happens.  This is known as ‘cosmic heat death’.

A fellow Scotsman, James Clerk Maxwell [1831-1879] believed that this challenged human free will.  He proposed a loophole in the second law of thermodynamics to demonstrate its falsity and invalidate the cosmic heat death argument.  Imagine Maxwell’s demon, as it became known, controlling a trapdoor separating two clouds of gas initially at the same temperature, which means the gas molecules in the two clouds have the same average internal energy.  The demon allows ‘hot’ molecules (i.e. those with higher than average internal energy) to one pass way through the trapdoor and ‘cold’ molecules (i.e. those with lower than average internal energy) to move the other way. After a period of time, all the ‘hot’ molecules will be on one side of the trapdoor and all the ‘cold’ molecules will be on the other side.  Heat has moved from colder (initial average temperature) to hotter (on one side of the trapdoor) and the second law has been contravened.

Maxwell created hope for the inventors of perpetual motion machines! [see my post entitled ‘Dream machine‘ on February 4th , 2015]  But then along came Leó Szilárd in 1929, who pointed out that the demon would have to expend energy [do work] to identify the internal energy of the molecules and to open the trap-door.  The second law was saved and cosmic heat death became a prospect once again although a very, very distant one.  Some modern physicists, though not Professor Brian Cox, reject the possibility of cosmic heat death by suggesting that the universe is too complex and our understanding too incomplete to allow Thomson’s simple reasoning to be applied.  John Updike protested against the idea in his poem ‘Ode to Entropy‘.  And on a human timescale, it is hard to believe that all tensions will ever be resolved.

Sources:

Ball, P., A demon-haunted theory, Physics World, April, 2013, p.36-9

Updike, J., ‘Ode to Entropy‘ available in the Faber Book of Science edited by John Carey 2005

Cox, B., Death of the Universe, World Space Week Special BBC Wonders of the Universe, 2013

Why is thermodynamics so hard?

boltzmannAn understanding of the second law of thermodynamics has been equated to reading Shakespeare in terms of its cultural significance [see my post entitled ‘Two Cultures‘ on March 5th, 2013].  So why do so few people understand it?

Perhaps it is the way that it is traditionally taught starting from a series of corollaries. Oops.  There is the first problem. Most students don’t know what a corollary is.  It is a statement that builds on a previous statement.

It is hard to find a simple statement of the second law of thermodynamics. There is the Clausius statement: no process is possible, the sole result of which is that heat is transferred from a cold body to hot body.  Then there is the Kelvin-Planck statement and if you really want to be confused then try the Carathéodory formulation.  You can read them at the bottom of this post to reassure yourself that they are impenetrable.  They were formulated when steam engines were the main source of energy and it is hard to see their relevance today in biology, chemistry and culture.

A more generic expression of the second law of thermodynamics is ‘entropy always increases’.  Oh, but now I’ve introduced entropy.  Entropy is a measure of disorder [see my posts entitled ‘Entropy management for bees and flights‘ on November 5th, 2014 and ‘Zen and entropy‘ on December 11th, 2013 ].  So according to the second law, the level of disorder must always increase. Boltzmann proposed that the level of disorder of a system could be quantified as a universal constant [k] multiplied by the logarithm of the number of ways [W] a system could be arranged with the same energy content.  Ok, so that’s getting complicated again.  But Boltzmann was so proud of it that it is carved on his grave stone [see picture] and the constant is known as the Boltzmann’s constant [=ratio of the molar gas constant and Avogadro’s number].

In an attempt to express the second law in everyday language, Bob and I re-wrote the second law as ‘you can’t have it just anyway you like it‘ in our book, The Entropy Vector.  In other words there always has to be some unwanted disorder created.

 

Statements (corollaries) of the second law of thermodynamics:

Clausius statement: no process is possible, the sole result of which is that heat is transferred from a cold body to hot body.

Kelvin-Planck statement: no process is possible, the sole result of which is that a body is cooled and work is performed.

Carathéodory’s formation: in every neighbourhood of every equilibrium state there is at least one state which cannot be accessed by an adiabatic process.

 

Sources:

Thess A., The Entropy Principle: Thermodynamics for the Unsatisfied, Springer-Verlag, Berlin, 2011.

Handscombe RD., & Patterson, EA., The Entropy Vector: Connecting Science and Business, World Scientific Press, Singapore, 2004.

Dream machine

Painting by Katy Gibson

Painting by Katy Gibson

A machine that can do work indefinitely without any external input of energy.  It would solve the world’s energy problems, eliminate global warming and make the inventor very rich.  There have been so many attempts to design such a machine that a classification system has been established.  My machine, that does work indefinitely with no energy input, would be a perpetual motion machine of the first type because energy is not conserved – a contradiction of the first law of thermodynamics.  The second type contravene the second law of thermodynamics, usually by spontaneously converting heat into work, and the third type eliminates friction and, or other dissipative forces.

I said ‘my machine’ in the sense that I have an on-going sporadic correspondence with the inventor of a machine that is claimed to produce ‘power above the primary power that drives it’.  It is an epistemic impossibility, which means that it cannot exist within our current understanding of the real world.  In other words, if a perpetual motion machine was to be proven to exist then the laws of thermodynamics would have to be rewritten.  This would probably lead to an invitation to Stockholm to collect a Nobel prize.

Such arguments make no difference to inventors of perpetual motion machines.  Many appear to start from the premise that the laws of thermodynamics have not been proven and hence they must not be universally applicable, i.e. there is space for their invention.  Whereas the laws of thermodynamics form part of our current understanding of the world because no one has demonstrated their falsity despite many attempts over the last two hundred years.  This is consistent with the philosophical ideas introduced by Karl Popper in the middle of the last century.  He proposed that a hypothesis cannot be proven to be correct using observational evidence but its falsity can be demonstrated.

So, inventors need to build and demonstrate their perpetual motion machines in order to falsify the relevant law of science.  At this stage money as an input usually becomes an issue rather than energy!

 

The painting by Katy Gibson is from a series made as part from an art and engine collaboration between Okemos High School Art Program and the Department of Mechanical Engineering at Michigan State University.