In this section, you will observe the different frequencies of light produced by three different light bulbs housed in a device that can switch each bulb on or off. Modern fluorescents try to simulate daylight conditions by producing colors of various "temperatures". A fluorescent bulb actually contains a mixture of electrically excited gases that produce light at a number of narrow frequencies. Our eyes, however, are poor spectrometers and thus perceive this light as similar to light from other types of lightbulbs. Some of these are included in the device; there is also a LED bulb and an incandescent bulb.

Using Wien’s law, you can calculate the temperature of a black body emitter if you know the peak wavelength. Wien’s law is 

Wein's law

where λpeak and T are in units of nanometers (nm) and Kelvin (K), respectively. 


Solar spectrum