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.
The slash ( /), also known as a stroke and by the technical term solidus, is a sign used as a punctuation mark and for various other purposes. It is often called a forward slash, a retronym used to distinguish it from the backslash ( \). It has many other names.
An invention is a unique or noveldevice, method, composition or process. It may be an improvement upon a machine or product, or a new process for creating an object or a result. An invention that achieves a completely unique function or result may be a radical breakthrough. Such works are novel and not obvious to others skilled in the same field.