Colour Temperature: Light vs Heat - What's the Difference?

[binbots]

Do different colours all have different temperatures? what are they? I know that the infrared spectrum is heat, so that must mean the whole spectrum is the same, right? What is the difference between light and temperature?

 

[mgb_phys]

As you heat an object it glows with a different color.
First infrared, then red (ie red-hot) then white then blue

Color temperature is a measure of how hot a glowing object (like the sun or a light bulb) would be to give the same color.
The sun is around 6600 deg, so to get the same blue-white light from an artificial source you need to heat the lamp to the same temperature (or mix red and blue light in the correct proportions). Regular light bulbs are much cooler, around 2500 deg so look much redder on photographs.

The temperature is measured in kelvin (K) which are like deg C - except they are no negative values. 0C is 273K and 100C is 373K so at the temperatures of lights you can think of it as deg C.

 

[Gerenuk]

Not all colours have temperatures. You can see the correspondence in the picture of
http://en.wikipedia.org/wiki/Black_body

Basically there are three elements here to know about:
1) an arbitrary spectrum where each frequency gets some intensity
2) a temperature and its corresponding black body spectrum (see top picture in the above link). this represents a specific spectrum that photons have if they happen to equilibrate with the object at that temperature
3) colour vision of the human eye knows about three values (roughly R,G,B)
Now what are the connections?

Now for each (1) you can calculate (3), but many spectra will correspond to the same colour (triple).

For each (2) where you have only the temperature parameter to adjust, you can also calculate (3), i.e. a colour triple, but this way you won't get all available colours.

 

[Eric McClean]

Check this out
www(dot)mediacollege(dot)com/lighting/colour/colour-temperature(dot)html

 

[sardar]

I can provide an explanation to the question of color temperature and the difference between light and heat.

First, let's clarify the concept of color temperature. It is a characteristic of visible light that describes the color of light emitted by an object when it is heated to a specific temperature. This temperature is measured in Kelvin (K) and is used to describe the color of light emitted by a perfect black body radiator, which is an object that absorbs all incident light and emits the maximum amount of radiation possible at a given temperature.

Now, to answer the question of whether different colors have different temperatures, the answer is yes. Each color has a specific temperature associated with it, and this temperature is related to the wavelength of light that the object emits. For example, red light has a longer wavelength and is associated with a lower temperature, while blue light has a shorter wavelength and is associated with a higher temperature. This relationship is known as Wien's displacement law.

However, it is important to note that the color temperature of an object is not the same as its physical temperature. The color temperature is only a characteristic of the light that is emitted by the object, while its physical temperature is a measure of the average kinetic energy of the particles that make up the object.

To address the idea that the entire spectrum is the same because the infrared spectrum is associated with heat, it is important to understand that heat is a form of energy, while light is a form of electromagnetic radiation. While both heat and light can be measured in units of temperature, they are fundamentally different forms of energy and cannot be equated to each other.

In conclusion, the difference between light and temperature lies in their nature as forms of energy. Color temperature is a characteristic of visible light, while physical temperature is a measure of the average kinetic energy of particles. While different colors have different associated temperatures, it is important to distinguish between the concepts of color temperature and physical temperature.