Prime purpose of this lecture is to present on Sources of Infrared Light. Infrared light from the Sun accounts for 49% of the heating of Earth, with the rest being caused by visible light that is absorbed then re-radiated at longer wavelengths. Infrared light is even used to heat food sometimes – special lamps that emit thermal infrared waves are often used in fast food restaurants! Shorter, near infrared waves are not hot at all – in fact you cannot even feel them.
Sources of Infrared Light
