Heat capacity of thermal radiation

In summary, the conversation discusses the need to demonstrate that the heat capacity of thermal radiation at constant pressure is infinite. The speaker proposes an argument, using the relationship Cp = dQ/dT at constant p, and concludes that if dP=0 and dT=0, then the denominator of Cp is zero, resulting in an infinite value for Cp. The interpretation of this is then discussed, with one person suggesting that it means adding or subtracting energy has no effect on temperature at constant pressure, while the other raises the issue of calculating the specific heat of a reflective volume of space.
  • #1
sachi
75
1
we need to show that the heat capacity of thermal radiation at constant pressure is infinity. I have an argument, but am not sure if it works. we know that Cp = dQ/dT at constant p, but we also know that p is a function of T only, and therefore that T is a function of P only, therefore if dP=0,dT=0, so the denominator of Cp is zero and Cp is infinite. we are then asked to interpret this. I think it means that adding energy or subtracting it makes no difference to temperature if the pressure is constant, i.e thermal radiation acts as a heat resevoir at constant P, or does it mean that we can't add/subtract energy at constant temperature?

thanks
 
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  • #2
Similar problem here. I'm conflicted by considering the release of energy into a volume of space. If you assume reflective boundary conditions, then I think the space could be taken to have some specific heat. I would like to know how to effectively calculate that.
 

1. What is heat capacity of thermal radiation?

The heat capacity of thermal radiation is the amount of thermal energy required to raise the temperature of a material by 1 degree Celsius. It is a measure of the material's ability to store and release heat energy.

2. How is heat capacity of thermal radiation measured?

The heat capacity of thermal radiation is typically measured using calorimetry, which involves heating a material and measuring the change in its temperature. The heat capacity is then calculated by dividing the amount of heat energy transferred by the change in temperature.

3. What factors affect the heat capacity of thermal radiation?

The heat capacity of thermal radiation is affected by the type of material, its mass, and its temperature. It also depends on the wavelength of the radiation, with longer wavelengths having a higher heat capacity.

4. How does the heat capacity of thermal radiation differ from other types of heat capacity?

The heat capacity of thermal radiation is unique in that it is not dependent on the material's physical properties, such as density or specific heat capacity. Instead, it is determined by the material's ability to absorb and emit thermal radiation.

5. Why is understanding heat capacity of thermal radiation important?

Understanding the heat capacity of thermal radiation is important in many fields, including engineering, materials science, and climate science. It helps us predict how materials will respond to changes in temperature and radiation, and can be used to develop more efficient systems for storing and transferring heat energy.

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