Energy

In physics, energy is a property of objects which can be transferred to other objects or converted into different forms, but cannot be created or destroyed. The "ability of a system to perform work" is a common description, but it is difficult to give one single comprehensive definition of energy because of its many forms. For instance, in SI units, energy is measured in joules, and one joule is defined "mechanically", being the energy transferred to an object by the mechanical work of moving it a distance of 1 metre against a force of 1 newton. However, there are many other definitions of energy, depending on the context, such as thermal energy, radiant energy, electromagnetic, nuclear, etc., where definitions are derived that are the most convenient.

Common energy forms include the kinetic energy of a moving object, the potential energy stored by an object's position in a force field (gravitational, electric or magnetic), the elastic energy stored by stretching solid objects, the chemical energy released when a fuel burns, the radiant energy carried by light, and the thermal energy due to an object's temperature. All of the many forms of energy are convertible to other kinds of energy, and obey the law of conservation of energy which says that energy can be neither created nor be destroyed; however, it can change from one form to another.

Major

Major is a military rank of commissioned officer, with corresponding ranks existing in many military forces. When used unhyphenated, in conjunction with no other indicators, the rank is just senior to that of an army captain and right below the rank of lieutenant colonel. It is considered the most junior of the field officer ranks.

Majors are typically assigned as specialized executive or operations officers for battalion-sized units of 300 to 1,200 soldiers. In some militaries, notably France and Ireland, the rank of major is referred to as commandant, while in others it is known as captain-major. It is also used in some police forces and other paramilitary rank structures, such as the New York State Police, New Jersey State Police and several others. As a police rank, Major roughly corresponds to the UK rank of Superintendent.

When used in hyphenated or combined fashion, the term can also imply seniority at other levels of rank, including general-major or major general, denoting a mid-level general officer, and sergeant major, denoting the most senior NCO of a military unit. The term Major can also be used with a hyphen to denote the leader of a military band such as in pipe-major or drum-major.