When we spoke earlier about conduction, we also mentioned rate of energy transfer. Here we can also talk about a similar concept, rate of energy transfer. But the formula here, it's different. The formula here is power, which is actually change in energy over time, which is a rate flow is equal to sigma, which is a constant and will be given to you admissitivity value A and T. T is the temperature of the object. A is the area of the face that's radiating the heat, and this is a value between zero and one. Now, where this value is one, that that simply means that the object is absorbing all the heat, is absorbing all the radiation, which means that it also releases all the radiation, okay?