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
How holography works. To create a hologram, you need an object (or person) that you want to record; a laser beam to be shined upon the object and the recording medium; a recording medium with the proper materials needed to help clarify the image; and a clear environment to enable the light beams to intersect.arious types of holograms have been made over the years, including transmission holograms, which allow light to be shined through them and the image to be viewed from the side; and rainbow holograms, which are used for security purposes â on credit cards and driver's licenses, for example. Recording a hologram.