Modern science is renowned for its complex calculations and manipulation of complex elements, yet most people do not realize that science is still limited by its inability to handle truly complex things. Physics and chemistry are relatively simple compared to biology, the weather, ecosystems and human systems such as economics, and it is precisely in these complex areas that humans are having a hard time.
For example, quantum physics maintains that everything can be explained in term of the Schrödinger equation, yet the equation itself is linear, and the world around us is most definitely not linear. Quantum physics suggests that randomness might solve the problem, but this is not yet a satisfactory explanation.
Theoretical physicist and YouTuber Sabine Hossenfelder explores the issue of complexity in a recent Youtube video. She discusses the problem and offers three elements useful in defining complexity.
The first is that complex systems have emergent properties. We can think of this as nested complexity, where different complexities and descriptions emerge at different sizes, temperatures, or states. Physics underlies chemistry, but the language of physics is not useful in describing chemical structures and reactions.
The second is that highly complex systems live on the edge of chaos, where it is not possible to predict that will happen next. This was originally an insight of Nobel prize winner Ilya Prigogine. Chaos theory has received a lot of attention in the last few decades.
The third element is that a complex system evolves and changes, which makes analysis difficult.
Sabine Hossenfelder discusses a few new theories of complexity, but it is clear that a science of complexity is still in its formative phase and that much more work needs to be done before we have tools to truly tackle and understand complex systems.
In the meantime, we should be cautious about promoting simple solutions for problems we know exist in a complex environment.