The History of Energy part two: Some background on the laws we learnt in school but never really understood!

We are pleased to continue the series in which Gareth Wyn Jones, Professor Emeritus of plant biology and bioscience at Bangor University considers the history of energy and asks what lessons it holds for today’s world.

Gareth Wyn Jones

In my first article I used Russia’s aggression in Ukraine to highlight society’s dependence on energy whether as fossil fuels or food calories.

Of course, this dependence also helps explain the reluctance of countries, businesses and us as individuals, to take the necessary steps to avoid catastrophic global warming.

Human quest

We hear plenty about the urgent need to reduce our dependence on the fossil fuels that power our society that are leading to the massive greenhouse gas emissions which cause man-made global warming; often called Anthropogenic Global Warming (AGW).

But we are failing to act decisively. Moreover, we hear little about the underlying and fundamental role of energy in both biology and human culture.

A good place to start is with a quotation from the Canadian physicist, Vaclav Smil, apparently one of Bill Gates’ favourite authors.

He wrote: “All natural processes and all human actions are, in the most fundamental physical sense, transformations of energy. Civilization’s advances can be seen as a quest for the higher energy use required to produce increased food harvests, to mobilise a greater output and variety of materials, to produce more, and more diverse goods, to enable higher mobility, and to create access to virtually unlimited amounts of information”.

Smil is here expanding on a concept which dates from before the World War I. In 1912 the Nobel Laurate Wilhelm Ostwald wrote “free energy is therefore the capital consumed by all creatures of all kinds and by its conversion everything is done”.

Let us underline the enormity of these assertions – all processes – all actions – all creatures – all kinds.

Every damn thing depends on energy transformations. But what of the term free energy, why transformations and why not just energy?

Fission or fusion

This takes us to some of the most fundamental laws in all science – the laws of thermodynamics. The first states ‘energy cannot be created or destroyed’.

After Einstein and the discovery of atomic structures – we saw that changes in matter, either by nuclear fission (atom bombs) or fusion (hydrogen bombs), can lead to the release of vast amounts of energy.

This means that we needed to revise the First Law  to ‘Energy and Matter’, taken together, cannot be created or destroyed.

Energy in its many and varied forms is defined by an ability to do work i.e. to make things change; be that to move clod or a tonne of earth, burn wood or coal to generate heat or cook or boil water to create steam or indeed the calories in our own food, which allow me to move my hand and to write and think, or the flow of electricity to turn a motor to run a fridge or a washing machine.

Fraud

In every case such energy transformations, as well as doing useful work, release a small amount of energy which is dissipated as low level heat e.g. from friction in a motor or the heat lost from our bodies (note: wear a hat on cold day as our brains use lots of energy!).

This lost energy is no longer able to do work. So, the term free energy refers to the part of the transaction that can do useful work while the small amount that is ‘lost’ i.e., can no longer do work, is termed entropy.

In any closed system entropy gradually increases and useful free energy deceases – this is why perpetual motion machines are always a fraud.

Fortunately, our planet Earth is not a closed system as, daily, the planet receives the radiant energy from thermonuclear reactions in the Sun. Not so much ‘give us this day our daily bread’ but give us this day our energy fix (which of course also helps provide our bread).

Disorder

The second law of thermodynamics can be paraphrased, as ‘everything will run down into disorder unless free energy is put into the system’ i.e., entropy tends continually to increase in given closed system.

At the level of molecules, say in a gas, entropy is also a measure of increasing internal disorder and randomness. So, when entropy is high, the system is more randomised and disordered.

Conversely when entropy is very low or negative, it means the system is more ordered and more complex.

In our daily lives we intuitively realise a very similar phenomenon. If you don’t put in the work i.e., use ‘energy’, then things tend to fall apart in our private lives, in the repair of our homes and socially.

But, of course, too much can also create a bull in china shop!

Entropy

An additional insight was provided by the famous physicist, Ludwig Boltzmann.

He conceived entropy as a statistical phenomenon which means that it is closely linked with what we all obsess about now ‘information technology’.

Information is defined by the number of simple binary (yes/no) decisions required to specify a unique condition or the state of a system.

Broadly the more decisions that are needed to define a given specific state or object, the higher the information content and the more ordered it is.

According to Boltzmann’s formula, entropy can be interpreted in similar terms. But it’s an inverse relationship – the better defined and more ordered a system, the lower its entropy.

Contradiction

However, in thinking about how these laws may apply on our world, there is an apparent contradiction.

The laws of thermodynamics mean that in any closed system e.g. the Universe, everything will gradually and irreversibly run down; giving us the arrow of time.

Although our Universe is expanding, it is a closed system in the sense that there is nothing outside beaming in energy or matter.

So, the entropy of the Universe must be increasing, leading, over eons of time, to the so-called ‘heat death’ of the Universe i.e. an order-less, cold and dead Universe, including planet Earth.

But the Earth we see daily is alive, complex, full of beauty and with a large measure of order. How come?

Scary

The first key point is that the Earth is not a closed system. We are in receipt of solar, thermonuclear-generated energy from our star, the Sun. This allows our Earth to exist without reaching equilibrium with near space or, let’s face it, our planet too would be cold and lifeless.

However crucially both physical experiments and theory have shown that, under specific conditions, energy transformations in systems well out of equilibrium with their environment can, spontaneously, lead to the creation of complex, well-ordered, albeit transient structures.

Perhaps the best known and often scary example of such a phenomenon on Earth is a hurricane which uses energy and matter from very warm oceans to create a vast ordered structure.

But it is one that soon dissipates when the energy source is lost e.g. when the hurricane makes landfall. Everyone has seen the beautiful photographs of hurricanes from satellites as well as reading of their destructive power.

The energy-driven structures then can be lost, ‘dissipated’ is the term used, due to both too much and too little energy. A very well explored and simple example of this phenomenon is the Benard cell.

Power

This physical background leads to a simple, perhaps deceptively simple, proposition: The more free energy that can be exploited under specific conditions, the more work that can be done and power applied (in physics, power is defined as work per unit time).

This, in turn, can be coupled to the spontaneous emergence of ‘structures’ of more and more ordered complexity.

However, in marked contrast to the hurricanes and the Benard cells mentioned earlier, in biology, such complex systems have found ways to stabilize themselves/be stabilized and cope with changes in energy and material flows.

And I will argue later the same holds for human society.

Change

In Energy the Great Driver; Seven Revolutions and the Challenges of Climate Change, I explore how these propositions can be applied to and, I believe, illuminate both biological and human history.

This exploration has shown that a number of important, revolutionary step-changes in the energy economy of our planet can be identified, as I will discuss in my next article.

These changes were very gradual in the early millennia but have accelerated dramatically: that is the time between the major revolutions has decreased dramatically.

The energy revolutions have not only had profound effects on life forms but also the chemistry of the Earth’s oceans, atmosphere and even geology.

However, I wish to add other new dimensions to this concept.

Firstly, the mechanisms by which stability can be achieved in these energy-dependent structures. Secondly, the other properties that have emerged over time. And thirdly the implications of this analysis both to our combating climate change crisis and how human society might emerge for it.

I am suggesting the stories we are telling ourselves need to change dramatically to avoid damaging our future.

NOTE: Others including John Maynard Smith and Eors Szathmary, Robert Ayres, Eric Chaisson, Tim Lenton and Andrew Watson and Olivia Judson have made similar but not identical proposals about the energy events. In the case of Eric Chaisson he has also applied similar concepts to the evolution of stars.

Read all the other installments of The History of Energy here.