Infrared radiation

• all objects emit and absorb infrared radiation,
• The amount of infrared radiation emitted depends on the temperature of the object
• the hotter an object is the more infrared radiation it radiates in a given time
• an object that's hotter than its surroundings emits more infrared radiation than it absorbs as it cools down. (e.g. cup of tea left on a table)
• a black surface is better at absorbing and emitting radiation than a white one
• a matte surface is better at absorbing and emitting radiation than a shiny one
• all objects emit electromagnetic radiation due to the energy in their thermal energy stores
• as the temperature of an object increases the intensity of every emitted wavelength increases. the intensity of shorter wavelengths increases more rapidly.
• The temperature of the earth depends on the amount of radiation it reflects, absorbs and emits.
• during the day lots of radiation is transferred to the Earth from the Sun and absorbed. This causes an increase in local temperature.
• at night less radiation is absorbed by the Earth than is being emitted so the local temperature goes down