Contextual Outline Humans are social animals and have successfully communicated through the spoken word, and then, as the use of written codes developed, through increasingly sophisticated graphic symbols. The use of a hard copy medium to transfer information in coded form meant that communication was able to cross greater distances with improved accuracy of information transfer. A messenger was required to carry the information in hard copy form and this carrier could have been a vehicle or person. There was, however, still a time limit and several days were needed to get hard copy information from one side of the world to the other. The discovery of electricity and then the electromagnetic spectrum has led to the rapid increase in the number of communication devices throughout the twentieth century. The carrier of the information is no longer a vehicle or person — rather, an increasing range of energy waves is used to transfer the message. The delay in relaying signals around the world is determined only by the speed of the wave, and the speed and efficiency of the coding and decoding devices at the departure and arrival points of the message. The time between sending and receiving messages through telecommunications networks is measured in fractions of a second allowing almost instantaneous delivery of messages, in spoken and coded forms, around the world. This module increases students’ understanding of the nature, practice, application and uses of physics and current issues, research and developments in physics.
1. The wave model can be used to explain how current technologies transfer information 1.1 - describe the energy transformations required in one of the following: • mobile telephone • fax/modem • radio and television • Mobile phones have a built-in microphone that changes sound waves into electrical signals. These signals are digitised, and transmitted as radio waves to a base station. This base station consists of a