Transcript: Wien’s Law states that the wavelength of the maximum emission in a thermal spectrum is inversely proportional to the temperature. The mathematical form of this relationship gives the dominate wavelength in a thermal spectrum, although it should be remembered that a thermal spectrum is very broad and spans an order of magnitude more in wavelength. For example, the surface of the Sun is at a temperature of about 5,700 Kelvin. Using Wien’s Law says that the peak of the thermal radiation is about 5 times 10-7 meters of wavelength of radiation which corresponds to greenish-yellow visible light. Your body however is at a temperature of just over 300 Kelvin. Using Wien’s Law at this temperature produces a wavelength of about 10-5 meters. This is fifteen or so times longer wavelength then the red end of the visible spectrum, so your body and anything at room temperature, such as the surfaces of all terrestrial planets, are emitting radiation that is far beyond the visible end of the spectrum at infrared wavelengths.