The Board of studies has set the broad outline for the context of this unit:
Humans are social animals and have successfully communicated within groups 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 a coded form meant that communication was able to cross greater spatial and time barriers. A messenger was required to carry the information in hard copy form and this messenger may be 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 messenger carrying 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. (The full text of the Stage 6 Physics Course is available from the NSW Board of Studies)
At the heart of all our modern communications systems is our use of light to transmit information. We started by sending electrical signals down wires, then through space and now down tiny tubes of glass. We started by sending one signal at a time and now we can send thousands. We started by processing the signals mechanically, then by using electronics and in the future we will use photonics to process light signals directly.
Throughout it’s history, the development of communications and communications technology has changed our world by bringing people into closer contact with each other. In it’s early years it overcame the tyranny of distance, global communications today has changed the nature of commerce and today the internet is making a reality of McLuhan’s "global village".
The unit is structured around the history of communications and communications systems and their evolving impact on human society. The structure combines the content of Course Outcome P8 (waves) with Prescribed Focus Areas P1 (the history of physics), P3 (applications and uses of physics), P4 (implications for society and the environment) and P5 (current issues, research and developments in physics).
This unit is designed for a Year 11 class of students of intermediate ability at a well-resourced school. The class has access, at least once per week, to a PC lab with sufficient machines for all students in the class.
The lesson structure is designed around a timetable accommodating 5 hours of lessons each week over 6 weeks providing for 30 hours of lessons in total.
In stage 5 students learnt to:
- Identify waves as carriers of energy (5.6.1a);
- Qualitatively describe features of waves including frequency, wavelength and speed (5.6.1b);
- Give examples of different types of radiation that make up the electromagnetic spectrum and identify some of their uses (5.6.1c);
- Distinguish between the absorption, reflection, refraction and scattering of light and identify everyday situations where each occurs (5.6.4a);
- Identify that some types of electromagnetic radiation are used to provide information about the universe (5.9.1b); and
- Describe some everyday uses and effects of electromagnetic radiation, including applications in communications technology (5.12a).
A key component of student assessments will be their efforts in the research project. This project will be set early in the course for individual (or group) presentations at the end of week 6 and will represent half of the assessment marks for the unit.
The other half of the unit assessment will be based on student records of their first-hand investigations as written in their notebooks. Notebooks will be collected at the end of each of the first 5 weeks with marks for each week representing 10% of the course total.
