Aristotle, the first person to think about the functioning of the brain, believed that it regulated body temperature while the heart controlled the emotions. Now, with sophisticated machinery, we can actually see inside the brain and observe how it functions, how different parts of the brain deal with memory, consciousness and the senses and how the electrical impulses are passed from one neuron to another at a speed of 400 kilometres an hour. The brain contains 100 billion neurons, enough to illuminate a light bulb if all their power were harnessed together. Between each neuron is a tiny gap which is bridged by chemical go-betweens which transmit our thoughts. Humans can alter the balance of their brains by submitting them to chemical changes, for example, by drinking a few pints.
Alcohol slows the chemical reactions in our brains.
Termites Robert Winston compares the brain to a mound of termites. None of them has an overall knowledge of what they are doing, but together, almost by chemical signals, they work to create complex structures. People can learn new skills easily The success of the brain depends on all its many units working in harmony. The brain has to adapt to new tasks. Like a child, an astronaut has to learn to move and function in an alien gravity-less world.