World of Thought

World of Thought

It was once thought, in the days before relativity, that light did propagate through a special medium that permeated all of space, called «the luminiferous aether ». But the famous Michelson-Morley experiment demonstrated that such an aether did not exist.

We sometimes hear of things that can travel faster than light. Something called “the speed of thought, is occasionally proffered. This is an exceptionally silly notion – especially since the speed of impulses through the neurons of or brains is about the same as the speed of a donkey cart. The human beings have been clever enough to devise relativity shows that we think well, but I do not think we can boast about thinking fast. The electrical impulses in modern computers do, however, travel at the speed of light.

The world of thought is divided roughly into two hemispheres. The right hemisphere of the cerebral cortex is mainly responsible for pattern recognition, intuition, sensitivity, creative insights. The left hemisphere presides over rational, analytical and critical thinking. These are the dual strengths, the essential opposites, that characterise human thinking. Together, they provide the means both for generating ideas and for testing their validity. A continuous dialogue is going on between the two hemispheres, channeled through an immense bundle of nerves, the corpus callosum, the bridge between creativity and analysis, both of which are necessary to understand the world.

The brain is a very big place in a very small space. Image: Nuclei Brain Cells Neurons. Drawing © Megan Jorgensen (Elena)

The information content of the human brain expressed in bits is probably comparable to the total number of connections among the neurons – about a hundred trillion, 10(14), bits. If written out in English, say, that information would fill some twenty million volumes, as many as in the world’s largest libraries. The equivalent of twenty million books is inside the heads of every one of us.

Most of the books in the brain are in the cerebral cortex. Down in the basement are the functions our remote ancestors mainly depended on – aggression, child-rearing, fear, sex, the willingness to follow leaders blindly. Or the higher brain functions, some – reading, writing, speaking – seem to be localized in particular places in the cerebral cortex. Memories, on the other hand, are stored redundantly in many locales. In such a thing as telepathy existed, one of its glories would be the opportunity for each of us to read the books in the cerebral cortices of our loved ones. But there is no compelling evidence for telepathy, and the communication of such information remains the task of artists and writers.

The brain does much more than recollect. It compares, analyses, synthesizes, generates abstractions. We must figure our much more than our genes can know. That is why the brain library is some ten thousand times larger than the gene library. Our passion for learning, evident in the behaviour of every toddler, is the proof of our survival.