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What effect does color have on heat?
Question Date: 2013-05-07
Answer 1:

Objects can have color two ways: they can either reflect light or emit light. Light can be thought of as a wave. We perceive color because of different wavelengths of light. (Keep in mind that we can only see a small portion of the full electromagnetic spectrum of light. See
microworlds for an example of all the different wavelengths of light)

When an object absorbs and reflects light, the energy in that light is transferred to that object and dissipated as heat. When an object absorbs most of the light in the visual spectrum, it looks black. If it scatters most of the light, it looks white. Black objects absorb more heat than white objects. If an object is orange, that object reflects orange light and absorbs light that is not orange. As far the effect of specific colors on heat, it is difficult to judge for example whether something orange or something green would absorb more heat. It depends on whether the two objects are the same material, the shininess of the objects, exactly what shade of green or orange they are, and what kind of light source is illuminating them.

Conversely, temperature can also have an effect on color. Everything emits light because of its temperature, and as something gets hotter, the wavelength of light it emits becomes smaller and therefore higher in energy. Right now you are emitting infrared light, light that is just lower in energy than red light. They even make infrared cameras that can "see temperature"

watch here, please

If a black object is heated, at around 480 °C (896 °F) it will start to glow a faint red color. As it increases in temperature the color will change from red to orange to yellow to white to blue. This is the reason why coals glow red, incandescent light bulbs glow yellowish white, and Bunsen burners glow blue. Bunsen burner flames are hotter than light bulb filaments, which are hotter than coals.

Answer 2:

This question could have multiple interpretations. First, a darker object will absorb more radiation than a lighter colored one, and will thus heat up faster under bright light.

Second, a very hot object that radiates heat often has a characteristic color via black body radiation. The color of a flame or star, for instance, can be used to identify how hot the object is.

Answer 3:

Great question! Heat and color are generally related in that you can tell the temperature of a heat source by its color. This is how scientists can determine, for example, the temperatures of stars that are way too far away to measure directly. A metal that is heated to a high temperature can also glow with a color. For instance, a metal with temperature around 900 degrees Fahrenheit (500 degrees Celsius) is about a faint red glow, while metals with temperature above 2500 F (1400 C) glow hot white.

Answer 4:

Depends on what you mean by color.

Color is what we see as the frequency of light. Light is composed of waves (which have a wavelength) or particles called photons (of which each particle carries a certain amount of energy). Bluer light has higher frequency, shorter wavelength, and more energetic photons, while redder light has lower frequency, longer wavelength, and less energetic particles. Of course, your red light can have the same amount of energy as a blue light, just with a larger number of these photons and a higher amplitude (height) of the wave.

All objects that have temperature emit light. The hotter the object, the brighter and bluer the light emitted will be. Most objects that you interact with on a daily basis (including your body) are at the right temperature to emit mainly infrared light, which is a color too red for us to see. Hot coals in a fire are hot enough emit red light, molten lava is hotter still and emits orange to yellow light, the sun is hotter yet and emits green light, and lightning is so hot that most of its light is actually ultraviolet, too blue for us to see, but most of the light that we can see from lightning is blue or violet.

Objects also reflect light that hits them, which determines the color of the object. Lighter-colored objects emit more light, and darker colored objects absorb more light. The more light an object absorbs, the more it heats up when it is exposed to light, which is why dark things get hot more quickly than light things if left out in the sun. However, all of this depends on the fact that there is something shining light onto them (in this case, the sun); color of objects that are not emitting light makes no difference whatsoever.

Answer 5:

Objects that are more darkly colored are dark because they reflect less visible light. This means they absorb more light. Energy from light striking an object is transferred to the molecules in the object. This extra energy excites electrons in the object's molecules and when the electrons "fall back down" to their "ground states" the energy is released in the form of infrared light, or heat. The heat is then either released or the object retains the heat. I hope this helps!

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