From Brian Whittaker
How does electricity move through a metal, your feature asks (29 May, p 38)? It’s difficult for me to see this as anything other than a simple displacement effect. If you push some marbles into a tube filled with marbles then some marbles will emerge from the other end. The fact that they are not the same ones is irrelevant, because something has been transmitted very quickly – call it force, or information. Whatever it is, it is not marbles.
With electrons in a wire, electrons are forced in at one end and displace other electrons, by collision, repulsion or whatever, until the disturbance, which happens to move at the speed of light, reaches the other end. What is being transmitted is actually information. The movement of sound in air seems a good analogy. Nitrogen and oxygen molecules cannot travel far without colliding, but this does not prevent the transmission of what we call sound, which is also a form of information. Electricity is both electron movement and information movement.
Maybe the ghost in the machine is information.
Wantage, Oxfordshire, UK
