What radiates more heat, white or black?

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In summary, the question is about which object, black or white, will radiate heat faster. The answer is that it depends on the surrounding temperature, as warmer surroundings will cause the object to absorb heat faster. However, the color of the object is not a determining factor in thermodynamics. It is the surface emissivity that affects the temperature of the object. In general, black objects tend to absorb more energy and emit more heat, but this is not always the case and other factors such as surface properties also play a role.
  • #1
ShawnD
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If I have 2 objects that are the same is every way except for the color, which object will radiate heat faster; the black or the white?
 
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  • #2
Black.
 
  • #3
FZ is right as the question is worded. However, it depends on if the surrounding space is warmer or colder. If it's warmer it will be absorbing heat faster.
 
  • #4
well i have never heard of white body radiation...
 
  • #5
It really is not that easy of a question to answer. Color is not specifically a factor in any thermodynamics relationship. What is a factor is surface emissivity. If the bodies are the same in every way the temperature of the 2 bodies will only be different the emissivity has changed. (This may well happen)
 
  • #6
Originally posted by Artman
FZ is right as the question is worded. However, it depends on if the surrounding space is warmer or colder. If it's warmer it will be absorbing heat faster.
Faster than what? The question wasn't whether it would absorb or emit, but which would emit more: Black. The way the equations work, you can consider an object to be simultaneously absorbing and emitting radiation.
 
  • #7
Ok now is there a reason for why black emits more? I mean like a real reason not just a vague logical explanation.
 
  • #8
Black tends to adsorp a wider band of energy then lighter colors which reflect more, thus black surfaces can be warmer then light. There is much more then just color involved, so this is pretty much a generaliztion which may not be true in every case.
 
  • #9
Originally posted by russ_watters
...The question wasn't whether it would absorb or emit, but which would emit more: Black. The way the equations work, you can consider an object to be simultaneously absorbing and emitting radiation.

He also said radiate HEAT faster. If the space around them is colder than the two objects, which will radiate heat faster? The energy emitted may not be in the form of heat.
 
  • #10
Actually the surroundings make no difference. Let's say you have 2 objects, one of them black and one of them not black and both are gaining more heat than they are emiting. The black object will radiate more heat as well as absorb more heat.
 

1. What is the difference between white and black in terms of radiating heat?

The main difference between white and black in terms of radiating heat is their ability to absorb and reflect light. White objects reflect most of the light that hits them, while black objects absorb most of the light. This means that black objects will also absorb more heat and radiate it at a higher rate than white objects.

2. Does the color of an object affect how much heat it radiates?

Yes, the color of an object does affect how much heat it radiates. As mentioned before, darker colors like black absorb more light and heat, thus radiating more heat than lighter colors like white.

3. Is there a scientific reason for why black objects radiate more heat?

Yes, there is a scientific reason for why black objects radiate more heat. This is due to the object's ability to absorb light. Darker colors have a higher absorption rate, which means they absorb more light and heat energy, and then radiate it at a higher rate.

4. Can the type of material affect how much heat an object radiates?

Yes, the type of material can also affect how much heat an object radiates. Materials with a high thermal conductivity, such as metals, are more efficient at absorbing and radiating heat compared to materials with low thermal conductivity, such as wood or plastic.

5. Does the color of an object affect its temperature?

Yes, the color of an object can affect its temperature. Darker colors, like black, absorb more light and heat energy, causing the object's temperature to increase. This is why dark-colored cars can feel hotter to the touch compared to lighter-colored cars on a sunny day.

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