Tag Archives: disorder

Everything is flux but it’s not always been recognised

Decorative photograph or ruins of Fountains Abbey next to River SkellI am teaching thermodynamics to first year undergraduate students at the moment and in most previous years this experience has stimulated me to blog about thermodynamics [for example: ‘Isolated systems in nature?’ on February 12th, 2020].  However, this year I am more than half-way through the module and this is the first post on the topic.  Perhaps that is an impact of teaching on-line via live broadcasts rather than the performance involved in lecturing to hundreds of students in a lecture theatre.  Last week I introduced the second law of thermodynamics and explained its origins in efforts to improve the efficiency of steam engines by 19th century engineers and physicists, including Rudolf Clausius (1822 – 1888), William Thomson (1827 – 1907) and Ludwig Boltzmann (1844 – 1906).  The second law of thermodynamics states that the entropy of the universe increases during all real processes, where entropy can be described as the degree of disorder. The traditional narrative is that thermodynamics was developed by the Victorians; however, I think that the ancient Greeks had a pretty good understanding of it without calling it thermodynamics.  Heraclitus (c. 535 BCE – c. 475 BCE) understood that everything is in flux and nothing is at rest so that the world is one colossal process.  This concept comes close to the modern interpretation of the second of law of thermodynamics in which the entropy in the universe is constantly increasing leading to continuous change.  Heraclitus just did not state the direction of flux.  Unfortunately, Plato (c. 429 BCE – c. 347 BCE) did not agree with Heraclitus, but thought that some divine intervention had imposed order on pre-existing chaos to create an ordered universe, which precludes a constant flux and probably set back Western thought for a couple of millennia.  However, it seems likely that in the 17th century, Newton (1643 – 1727) and Leibniz (1646 – 1716), when they independently invented calculus, had more than an inkling about everything being in flux.  In the 18th century, the pioneering geologist James Hutton (1726 – 1797), while examining the tilted layers of the cliff at Siccar Point in Berwickshire, realised that the Earth was not simply created but instead is in a state of constant flux.  His ideas were spurned at the time and he was accused of atheism.  Boltzmann also had to vigorously defend his ideas to such an extent that his mental health deteriorated and he committed suicide while on vacation with his wife and daughter.  Today, it is widely accepted that the second law of thermodynamics governs all natural and synthetic processes, and many people have heard of entropy [see ‘Entropy on the brain’ on November 29th, 2017] but far fewer understand it [see ‘Two cultures’ on March 5th, 2013].  It is perhaps still controversial to talk about the theoretical long-term consequence of the second law, which is cosmic heat death corresponding to an equilibrium state of maximum entropy and uniform temperature across the universe such that nothing happens and life cannot exist [see ‘Will it all be over soon?’ on November 2nd, 2016].  This concept caused problems to 19th century thinkers, particular James Clerk Maxwell (1831 – 1979), and even perhaps to Plato who theorised two worlds in his theory of forms, one unchanging and the other in constant change, maybe in an effort to dodge the potential implications of degeneration of the universe into chaos.

Image: decaying ruins of Fountains Abbey beside the River Skell.  Heraclitus is reported to have said ‘no man ever steps twice into the same river; for it’s not the same river and he’s not the same man’.

Subtle balance of sustainable orderliness

129-2910_IMGI wrote this short essay a couple of weeks for another purpose and then changed my mind about using it.  So I thought I would share it on this blog.

Whenever we do something, some of our useful resource gets converted into productive activity but some is always lost in useless waste.  In other words, 100% efficiency is impossible – we can’t convert all of our resource into productive activity.  Engineers call this the second law of thermodynamics.  Thermodynamics is about energy transitions, for instance converting chemical energy in fossil fuels into electrical energy in a power station, and in these circumstances, the useless waste is called entropy.  At the time of the industrial revolution, Rudolf Clausius recognised that entropy can be related to the heat losses which occur whenever we do something useful, such as generating electricity in a power station, cleaning the house with an electric vacuum cleaner or running to catch the bus.

Clausius’s definition of entropy was really useful for designers of 19th century steam engines but it is difficult to use in other walks of life.  Fortunately Ludwig Boltzmann gave us a more valuable description.  He equated entropy to the number of states in which something could be arranged, or its lack of orderliness.  In other words, the more ways you can arrange something, the less ordered it is likely to be and the higher its entropy.  So a box of children’s building blocks has a low entropy when the blocks are packed in their box because there is a relatively small number of ways of arranging them to fit in the box.  When the box is emptied onto your living room floor, there are very many more possible arrangements and so the blocks have a high entropy.  The chance of knowing the whereabouts of a particular block is small. Whoops!  Now we’ve wondered into information theory.

Let’s get back to the second law, which using Boltzmann’s description of entropy, we can express as the level of orderliness should always decrease.  Stephen Hawking describes this as the arrow of time.  Because, if someone shows you a video clip in which steam gathers itself together and returns into a cup of coffee, or that box of children’s blocks repacks itself, then we know the video is being run backwards because these processes involve decreasing entropy and this can only happen spontaneously if we reverse the direction of time.  If this is true then why do we exist as highly ordered structures?

Erwin Schrödinger in his book, ‘What is Life’ says that organisms suck orderliness out of the environment in order to exist, so that the orderliness of the universe, that’s the organism and its environment, decreases.  Humans digest highly-ordered food to sustain life and food, in the form of plants, is brought into existence by metabolising energy from the sun and releasing entropy in the form of heat.  When we die these processes cease and the orderliness is sucked out of us to sustain insects, maggots and bacteria.

We are organisms, known as Sapiens, that organise ourselves into cultures and societies.  Organisation implies an increase in the level of orderliness in apparent contradiction of the second law.  So, we would expect to find a corresponding increase in disorder somewhere to counterbalance the order in society.  The more regimented society becomes the greater the requirement for counterbalancing disorder to occur somewhere in order to satisfy the second law, which might happen unexpectedly and explosively if the level of constraint or regulation is too great.  This is not an argument for anarchy or total deregulation, the financial sector has already demonstrated the risks associated with this path, but for an optimum and sustainable level of orderliness.  This requires subtle judgment just like in elegant engineering design and living a healthy life, both physically and psychologically.