Thermodynamics is a branch of natural science concerned with heat and its relation to energy and work. It defines macroscopic variables (such as temperature, internal energy, entropy, and pressure) that characterize materials and radiation, and explains how they are related and by what laws they change with time. Thermodynamics describes the average behavior of very large numbers of microscopic constituents, and its laws can be derived from statistical mechanics.
Cake is a form of bread or bread-like food. In its modern forms, it is typically a sweet bakeddessert. In its oldest forms, cakes were normally fried breads or , and normally had a disk shape. Determining whether a given food should be classified as bread, cake, or pastry can be difficult.
