Classical unified field theories accepted by physicists. Classical unified field theories Since the 19th century, some physicists, notably Albert Einstein, have attempted to develop a single theoretical framework that can account for all the fundamental forces of nature – a unified field theory. Classical unified field theories are attempts to create a unified field theory based on classical physics. In particular, unification of gravitation and electromagnetism was actively pursued by several physicists and mathematicians in the years between the two World Wars. This work spurred the purely mathematical development of differential geometry. This article describes various attempts at formulating a classical (non-quantum), relativistic unified
Unified combatant command forces in an efficient "unified combatant command" force. Furthermore, the Secretaries of the Military Departments (i.e. Secretary of the Army, Secretary of the Navy, and the Secretary of the Air Force) are legally responsible to "organize, train and equip" combatant forces and, as directed by the Secretary of Defense, assign their forces for use by the combatant commands. The Secretaries of the Military Departments also do not exercise any operational control over their forces. Each combatant command can be led by a generalor flag officer from any of the military services. Unified combatant command A unified combatant command (UCC) is