The scale of the global network of brains and the universe
April 17, 2011 § 1 Comment
Astronomers have recently increased the estimation of the number of stars in the known universe (P. van Dokkum & C. Conroy. A substantial population of low-mass stars in luminous elliptical galaxies. Nature, 2010) and it is now of the order of 3 x 100,000,000,000,000,000,000,000, or to put it into a readable form, 3 x 1023. While this long line of zeros would not surprise us even if there were 10 zeros more in these numbers beyond our understanding, one of the authors had noticed an interesting coincidence (cf. Huffpost Green): a simple calculation by Conroy suggested that the rough number of cells in the human bodies on earth is also of the order of 1023, in other words, the total number of cells in all the human bodies on earth equals the number of stars in the universe. This is a reminder of the scale of the scientific challenges facing us in studying the biology of life and especially it gives something to think about for brain scientists who might believe that we have come close in solving the problem of the human brain. There is another inspiring message in these numbers.
Neural connectivity of the mankind
The human brain has roughly 1011 neurons and each of them has, on average, thousands of synaptic links to other neurons. It is possible that the estimated number of these connections will increase when more is known about the combined hormonal, chemical and electric nature of cell communication. Nevertheless, it is not a monumental mistake to assume that number of synapses per neuron is of the order of 10000 or 104. If we take the human population on earth that is 1010 we can realize that the total number of neuron connections (synapses) on earth, in the human brains, is of the order of 10 11+4+10 = 1025 = 10 000 000 000 000 000 000 000 000. I really don’t know what to call this exhausting number but it tells that all the human neural connections are significantly more abundant than the estimated number of stars in the universe. Why should this matter?
Global synaptic connection mass as a theoretical upper limit for human culture potential
One can think of the neural synapses as the structure, mechanism and information architecture through which change and learning in life can take place. The huge number 1025 of connections in the brains of the mankind invites us to think about the global connected neuron population in all the human brains as the potential network that the human global society and all its cultures have as the resource for developing now and in the future.
Anyone can understand that while a single brain with its 1015 connections has some limitations, the total brain pool has an amazing potential – if it can be used. One cannot avoid thinking that this simple “neuro-cultural computation” provides an immense call to all of us to think theoretically, how much potential we have as a human species and community. In this sense the problem is analogous to the estimation of the number of stars in the known universe.
There is also another, perhaps wild but delicious analogy: stars are connected with each other via gravitation and radiation. Is it then possible to consider the gravitational forces in the stellar systems as an analog to the synaptic connections between neurons and also between different brains? Gravitation regulates the dynamic and mechanic relationships between the stars and galaxies and it determines their ways of communicating with electromagnetic radiation. Not quite similarly, but interestingly though, in the same sense there are only a few material ways of communication between different brains: it has to happen via synaptic activities: the synapses in our brains are used and altered every time we are affected by the nature or by the direct or indirect actions of other human beings and life on earth in general.
In this speculative sense, our environment and other people act on us just like gravitation acts on other stellar systems. But neither of these mechanisms is scientifically understood: how and by which exact mechanism does gravitation affect distant objects or how the synapses of our brains are changed via external events by direct or indirect communication. All we can right now do in science is to observe and somewhat also predict the constellations of the stars and the changes in the brains (our behavior) but the true underlying mechanisms remain still hidden.
Togetherness via synapses
A sceptic may claim that our brains are not physically connected and that information does not flow directly from a neuron of one brain to a neuron of another brain and that pooling the brain networks together in the calculations as I have done here makes no sense.
But our brains are continuously connected in numerous indirect ways, not least due to the global communication technology: in the way we transform our environment for other to see, feel, experience and live in or in the way we communicate, create and shape cultures around us and globally. An especially effective way to have an impact on others is in the way we transform our environment. It is possible to think that the huge human synaptic connection mass in all human brains is the only known upper limit for the development of the human culture. This potential gives hope: it is difficult to imagine any limitation to our cultural and human development due to this immense information theoretical limit. On the other hand it makes one wonder, what is the nature of this inter-brain networking? How are we, actually, connected with each other’s brains?
Of course we can think about all this from a number of constraining perspectives: human information processing, human physiology and anatomy in general, development and evolution, food and drugs, environmental changes, and any other factors that alter our brains. But nothing in the human life on earth happens without the presence of these synaptic forces of change and we cannot achieve more that this potential allows. In that sense, it is an inspiring scientific challenge to make these calculations and read their story to the human cultural potential, in good and bad. These or similar computational considerations can form a basis for looking at the information theoretical constraints that our networked brains provide to the civilization and human beings on earth. Based on these simple computational speculations, these extreme values are as far as the limits of the known universe. But then of course, it is possible that the theory of synapses collapses and the computed limits will change, just as it is continuously happening in astronomy. The good side of all this is that the limits will be pushed farther.
The photo above is from Stanford, I thank Sayed Shariq for the inspiring synaptic energy.