1. Thermal radiation is energy transfer by waves.        A dull black surface is a good absorber of radiation.        A bright shiny surface is a poor absorber of radiation.    2. A skier's jacket has a shiny surface to reduce heat loss by radiation.    3. The surface of a radiator transfers energy to the surroundings by infra red waves passing         through the air.    4. People can be seen in darkness through Infra-red camera which detect the heat emitted from        people's bodies.        5. How Science Works        Kate investigates what colour of a surface is a good absorber of heat.        a) The independent variable is the colour of the surface.        b) The colour of the surface is a categoric variable.        c) The dependent variable is temperature.        d) Temperature is a continuous variable.