“If you look at the entire physical cosmos, our brains are a tiny, tiny part of it. But they’re the most perfectly organized part.” says Noble-Prize winner, physicist Sir Roger Penrose, comparing the complexity of the universe to the human brain with its cerebral cortex, the folded gray matter that covers the first couple of millimeters of the outer brain like wrapping paper, where “matter is transformed into the mystery of consciousness.”“I have a much easier time imagining how we understand the Big Bang than I have imagining how we can understand consciousness,” says Edward Witten, theoretical physicist and ‘father’ of string theory at the Institute for Advanced Study in Princeton, New Jersey.
Two of the Most Challenging and Complex Systems in Nature
Enter astrophysicist Franco Vazza at the University of Bologna and Alberto Feletti a neurosurgeon at the University of Verona who have investigated “the similarities between two of the most challenging and complex systems in nature: the cosmic network of galaxies and the network of neuronal cells in the human brain despite the substantial difference in scale between the two networks (more than 27 orders of magnitude). Their quantitative analysis, which sits at the crossroads of cosmology and neurosurgery, suggests that diverse physical processes can build structures characterized by similar levels of complexity and self-organization.”
Galaxies and Neurons
The human brain functions thanks to its wide neuronal network that is deemed to contain approximately 69 billion neurons. On the other hand, the observable universe can count upon a cosmic web of at least 100 billion galaxies. Within both systems, only 30% of their masses are composed of galaxies and neurons. Within both systems, galaxies and neurons arrange themselves in long filaments or nodes between the filaments. Finally, within both systems, 70% of the distribution of mass or energy is composed of components playing an apparently passive role: water in the brain and dark energy in the observable Universe.
Starting from the shared features of the two systems, researchers compared a simulation of the network of galaxies to sections of the cerebral cortex and the cerebellum. The goal was to observe how matter fluctuations scatter over such diverse scales.
“Calculating the Spectral Density”
“We calculated the spectral density of both systems. This is a technique often employed in cosmology for studying the spatial distribution of galaxies”, explains Vazza. “Our analysis showed that the distribution of the fluctuation within the cerebellum neuronal network on a scale from 1 micrometer to 0.1 millimeters follows the same progression of the distribution of matter in the cosmic web but, of course, on a larger scale that goes from 5 million to 500 million light-years”.
Neuron Network and the Cosmic Web
The two researchers also calculated some parameters characterizing both the neuronal network and the cosmic web: the average number of connections in each node and the tendency of clustering several connections in relevant central nodes within the network.
“Once again, structural parameters have identified unexpected agreement levels. Probably, the connectivity within the two networks evolves following similar physical principles, despite the striking and obvious difference between the physical powers regulating galaxies and neurons”, adds Alberto Feletti. “These two complex networks show more similarities than those shared between the cosmic web and a galaxy or a neuronal network and the inside of a neuronal body”.
The results of this seminal study are prompting the researchers to think that new and effective analysis techniques in both fields, cosmology, and neurosurgery, “will allow for a better understanding of the routed dynamics underlying the temporal evolution of these two systems”.
Source: Frontiers of Physics with the title “The quantitative comparison between the neuronal network and the cosmic web”. Its authors are Franco Vazza from the Department of Physics and Astronomy of the University of Bologna, and Alberto Feletti from the Department of Neurosciences, Biomedicine, and Movement of the University of Verona.
The Daily Galaxy, Jake Burba, via University of Bologna
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