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
An electroencephalogram (EEG) is a recording of brain activity. During the test, small sensors are attached to the scalp to pick up the electrical signals produced when brain cells send messages to each other.hen an EEG is used. An EEG can be used to help diagnose and monitor a number of conditions affecting the brain. It may help identify the cause of certain symptoms â such as seizures (fits) or memory problems â or find out more about a condition you've already been diagnosed with.