Peter Cochrane: Non-linearity is the norm and defies simple thinking

Disciplines are becoming more specialised at a time when global challenges have become more complex. Solving them may require the non-linear calculations that only quantum computing can provide, says Professor Peter Cochrane

Prior to the Reformation there were no intellectual divisions between art, science, maths and engineering, it was all one, broad discipline. But, as complexity mounted, they diverged as distinct disciplines.

This specialisation helped accelerate progress in each field and continues to do so today. However, we now face a new challenge, one of ever-more hyper-specialisation that is creating highly niche, isolated and insulated disciplines.

Hyper-specialisation continues and intellectual disciplines become ever narrower

Perhaps the most graphic manifestation of this are students who have become so subject-focused that they see the world through a narrow ‘soda-straw' of knowledge. Sure, they can build AI systems, but know nothing of hardware or interfaces. They can design electronic devices, but can't code or understand the underlying mathematics of information and measurement accuracy.

Nevertheless, hyper-specialisation continues and intellectual disciplines become ever narrower. Sometimes this can be at the expense of overlooking what is often already known and may be obvious!

Two recent examples have variously seen the realisation that the human brain will never be understood by the human brain, and that digital computers are fundamentally limited when modelling non-linear systems on a large scale, such as climate change and weather patterns.

Four billion number floating-point arithmetic still isn't large enough to accurately model weather or climate systems

Those engaged in studying the human brain have spent decades applying models, sensors, scanners and thousands of experiments.

Even though 20 years ago extensive efforts to map the brains of nematodes revealed little more than a neural road map, they plodded on. If only they had studied thermodynamics and the second law (of entropy) in the first case, and uncertainty theory in measurement and observation in the second - they could have got to the bottom line in minutes, not decades!

Recently, it has been realised that four billion number floating-point arithmetic still isn't large enough to accurately model weather or climate systems. The so-called ‘butterfly effect' means that just a tiny change in one parameter can cause violent outcomes overall. This is a well known and well-documented characteristic of non-linear systems, but overlooked by the linear thinkers.

Digital computers will never be able to accurately model chemical reactions, biological life or the behaviours of societies and markets at any scale

While non-linear systems are mostly seen as the exception, the reality is that they are the norm across the universe, and it turns out that pure linearity is extremely rare.

Hence, digital computers will never be able to accurately model chemical reactions, biological life or the behaviours of societies and markets at any scale. For that ability, we will have to look to quantum computing and a more analogue future more suited to describing all the statistical possibilities, while also identifying the tipping points defining new phase and state changes.

I'm now going to predict a counter-intuitive feature for global warming studies: In a linear world, the path to global warming would be one we could simply reverse back down by cutting carbon emissions and pollution.

^{Four potential temperature scenarios for global warming. Image by Peter Cochrane}

This seems to be the understanding of politicians and the green lobby, but that's not the way our non-linear planet works. We started with an industrial revolution that triggered massive industrial growth, as well as a spike in CO2 emissions as result, with cumulative damage, including most recently ice melt releasing methane from the tundra and a warming of the oceans.

On this basis alone we have created a global warming process we possibly can't reverse by going into reverse gear! Even if we cut our CO2 emissions to zero, we are heading for a new stability point and we have no idea where it is or the implications of it.

We have created a global warming process we possibly can't reverse by going into reverse gear

At the same time, planting billions of new trees across the planet as the Amazon is logged to extinction could achieve a new climatic equilibrium that might just make the tropics uninhabitable with London and Paris becoming the new sub-tropics. On this journey there's a high chance that we will see the extinction/reduction of entire insect and animal species, along with plants.

But with our current ‘tools' we simply can't accurately or honestly predict how this might end - although it's something that quantum computing could very well do, or at the very least help us with.

Professor Peter Cochrane OBE is the former CTO of BT, who now works as a consultant focusing on solving problems and improving the world through the application of technology. He is also a professor at the University of Suffolk's School of Science, Technology and Engineering