One of the most important open questions in science is how our consciousness is established. In the 1990s, long before winning the 2020 Nobel Prize in Physics for his prediction of black holes, physicist Roger Penrose teamed up with anaesthesiologist Stuart Hameroff to propose an ambitious answer.
They claimed that the brain’s neuronal system forms an intricate network and that the consciousness this produces should obey the rules of quantum mechanics – the theory that determines how tiny particles like electrons move around. This, they argue, could explain the mysterious complexity of human consciousness.
Penrose and Hameroff were met with incredulity. Quantum mechanical laws are usually only found to apply at very low temperatures. Quantum computers, for example, currently operate at around -272°C. At higher temperatures, classical mechanics takes over.
Since our body works at room temperature, you would expect it to be governed by the classical laws of physics. For this reason, the quantum consciousness theory has been dismissed outright by many scientists – though others are persuaded supporters.
However, a simple approach between the ability of quantum computing to accomplish tasks that are extremely complex compared to ordinary computers; It suggests that our brains’ complex capabilities may be explained by quantum mechanics, too. Here we have to test some of the governing principles on which the theory of quantum consciousness is built.
Recently, a group of scientists in China studied how quantum particles move within complex structures that might resemble the brain. The results of the study were published in the journal Nature Photonics on July 19.
Fractals in our brains
Our brains are composed of cells called neurons, and their combined activity is believed to generate consciousness. Each neuron contains microtubules, which transport substances to different parts of the cell.
Quantum consciousness theory suggests that microtubules are shaped as “fractal patterns” that allow quantum processes to occur.
“Fractals” are defined as very small geometric structures with infinitesimal dimensions, and these structures are made up of smaller and smaller parts that repeat the same geometric pattern in the parent fraction over and over again. Thus, it generates fractal patterns that appear miraculous and have a structure with limited space and unlimited perimeter (dimensions).
The fractal patterns are repeated in nature as well as inside our bodies, as is the case in the structure of the bronchi and bronchioles that make up the lung, as well as in the structure of vessels and capillaries.
It’s easy to see why fractals have been used to explain the complexity of human consciousness. Because they’re infinitely intricate, allowing complexity to emerge from simple repeated patterns, they could be the structures that support the mysterious depths of our minds.
But if this is the case, it could only be happening on the quantum level, with tiny particles moving in fractal patterns within the brain’s neurons. That’s why Penrose and Hameroff’s proposal is called a theory of “quantum consciousness”.
We’re not yet able to measure the behaviour of quantum fractals in the brain – if they exist at all. But advanced technology means we can now measure quantum fractals in the lab. In recent research involving a scanning tunnelling microscope (STM), my colleagues at Utrecht and I carefully arranged electrons in a fractal pattern, creating a quantum fractal.
When we then measured the wave function of the electrons, which describes their quantum state, we found that they too lived at the fractal dimension dictated by the physical pattern we’d made. In this case, the pattern we used on the quantum scale was the Sierpiński triangle, which is a shape that’s somewhere between one-dimensional and two-dimensional.
The scientists noticed that the transmission of photons within these quantum fractal structures is quite different from the transmission in the classical case; There was a clear anomaly in how it was transmitted, as it depends on the dimensions of the fractal structure only. They also showed that the transition from the normal state to that anomaly depends on the fractal geometry.
Thus, this new knowledge of the foundations governing motion in quantum fractals may pave the way for an empirical test of quantum consciousness theory. If similar measurements were made to the human brain and were similar to these results, we might be able to know the reality of consciousness; Is it a quantum phenomenon or a classical one?
Published: 19 July 2021 in the Journal Nature – Quantum transport in fractal networks