Feet Definition. A foot (pl. feet) is a common length unit used in Imperial system and the current US customary unit system. A foot is equal to 0.3048 meter. This unit of length has been used in Europe since the times of the Roman Empire and ancient Greece. A foot has 12 inches, and 3 foot make a yard.
Holography is the science and practice of making holograms. Typically, a hologram is a photographic recording of a light field, rather than of an image formed by a lens, and it is used to display a fully three-dimensional image of the holographed subject, which is seen without the aid of special glasses or other intermediate optics. The hologram itself is not an image and it is usually unintelligible when viewed under diffuse ambient light. It is an encoding of the light field as an interference
Full Definition of KILOGRAM. 1. : the base unit of mass in the International System of Units that is equal to the mass of a prototype agreed upon by international convention and that is nearly equal to the mass of 1000 cubic centimeters of water at the temperature of its maximum density â see metric system table. 2.. : a unit of force or weight equal to the weight of a kilogram mass under a gravitational attraction equal to that of the earth. See kilogram defined for English-language learners. See kilogram defined for kids.