The Goldilocks Principle: why size and scale must be just right | The Dyson Blog

Have you ever spent much time thinking about why things are the size they are?

I have often come back to contemplating this topic when reading about mitochondria. We have mitochondria in all our cells, they convert carbohydrate molecules into packets of energy (ATP) that can then be used directly by our cells to function. ATP powers muscle cell contraction, protein building, cell replication. 

To go down a rabbit hole briefly, these fascinating organelles are the vestiges of ancient bacteria which somehow became intertwined with the larger eucaryote cells of animals and plants. They have their own DNA which is only passed on through the female line. The way they produce ATP is by becoming self-charging batteries of 180mV which drives all the processes in a cell.

To get back to scale; do we have one of these in each cell? The answer is no, we have a few 100,000 per cell. Over millions of years of evolution although much has changed, they have not changed in size, because the size and structure represent a sweet spot for their function. You could say that we have learned similarly in the building of batteries; replicating and combining small cells works much better than trying to create large cells. The body itself carries on the advantages of scaling. An organ contains some hundred billion cells and the body is made up of about 100 organs and limbs. 

If we look more broadly into the living world, we can see that size and scale are really important factors in function, efficiency, and survival. Human beings are not accidentally the size we are. We’re a size that allows us to travel long distances. We developed in the Rift Valley in Africa, a landscape that was rapidly changing, in relative terms, creating new and diverse habitats. To survive and exploit this, we needed to be able to travel, develop technologies (fire and tools), problem solve, and adapt. Homo erectus, our earlier cousin, could do all these things and spread out globally surviving and developing for a million years. Interestingly, Homo sapiens, us, developing later and in parallel were a bit smaller. The current view is that the advantage was size and reduced testosterone leading to less aggression and the ability to create and work in large social groups.

Mammals, themselves really came into their own after the last mass-extinction event some 65 million years ago. They were overall much smaller than the dominant animals - the dinosaurs - and their size and adaptability is seen as a key feature for their survival and thriving.

Moving away from the natural world into the world designed by Homo sapiens, there is a very different approach to scale. Things are scaled up and down from the size of a human. Houses and buildings are sized to wrap around humans and floor heights set to allow humans to walk upright. The first factories were simply extensions on houses and the machines and equipment were generally sized to fit into slightly large rooms. Of course, technology has pushed these boundaries to some degree and there are now large process plants like refineries or mega-factories.

The railway system of the world is scaled around the size of a horse and cart as that was the predominant transport technology when they came into existence. 

Moving down in scale, we scale craft and industrial laboratory equipment so that humans can interact with it using their hands.

Evolution is an excellent process to improve and adapt size and function to meet the demands of survival. Its downside for humans is that in the context of the human lifespan it is very slow. We do not have the luxury of a million years to size our factories. However, neither should we now be constrained by the size of a human, a building or by the relatively recent economic dogma. 

I don’t think we can credibly argue that capitalism has not been a key enabler in the rapid technological advancements of the last two to three hundred years. And when we talk about capitalism, we cannot ignore the name Adam Smith. The problem I have with the way we’ve taken Smith’s thoughts and works is that it is piecemeal and skewed – we’ve latched onto some of his insights without exploring them more widely. He was one of the first theorists to develop the idea of the economy of scale. How making things bigger, growing operations tends toward greater economic efficiency. He was right, in some circumstances. The problem is that such simple rules, although alluring, can be unhelpful or plain wrong in other circumstances. 

When lecturing my students, I discuss the dis-economy of scale. How large processes need large peak demands of inputs, how many design factors are not linear so doubling the size of a process can mean 4x or 8x the energy, the time, or the effort. For some processes, a colony of ants would be much more efficient than a brontosaurus. 

The point is that scale is a complex but critical issue if you are concerned with multiple factors – profitability, economic agility, sustainability, system reliability. We cannot just keep doing what we have always done or following over-simplistic thinking. The technological advances of the last 50 years have allowed us to be able to model scenarios from millisecond by millisecond to decade by decade. This allows us to control processes at both ends of the scale – from an oil refinery to a micro robot. This is a time when we need to learn from nature and think hard about scale.

Going back to the rise of mammals or Homo sapiens, a change in scale is an adaptation to a transforming environment. This is arguably exactly where we are today with industrialisation – the ground is shifting quickly, fissures are opening up, lethal challenge and paths to opportunity are open to us like they were to our ancestors in the Rift Valley. We need to be at the right scale to survive and prosper.

More in my next Blog…