what is thermal constancy?
Temperature constancy occurs when the thermal energy emitted by an object is equal to the thermal energy absorbed by that object.
Any object with a temperature above absolute zero emits black body radiation. As the temperature increases the energy emitted increases.
Objects will absorb radiation that incidents its surface. The colour and reflectivity of the object determine the amount of radiation absorbed.
When the rate of energy emission and the rate of energy absorption are equal the object will remain at a constant temperature.
If the rate of emission is greater than the rate of absorption then the object will decrease in temperature until the rates are equal and it achieves temperature constancy.
If the rate of emission is less than the rate of absorption then the object will increase in temperature until the rates are equal and it achieves temperature constancy.