Phi phenomenon

The phi phenomenon is the optical illusion of perceiving a series of still images, when viewed in rapid succession, as continuous motion. Max Wertheimer defined this phenomenon in 1912. The phi phenomenon and persistence of vision together formed the foundation of Hugo Münsterberg's theory of film and are part of the process of motion perception.

The phi phenomenon is similar to beta movement in that both cause sensation of movement. However, the phi phenomenon is an apparent movement caused by luminous impulses in sequence, whereas beta movement is an apparent movement caused by luminous stationary impulses.

Persistence of vision

Persistence of vision, which is popularly taught as the reason for motion illusion, is in reality merely the reason that the black spaces that come between each "real" movie frame are not perceived, which makes the phi phenomenon the true reason for motion illusion in cinema and animation, including the phenakistoscope, zoetrope, and others.

Experimental demonstration

Gestalt psychology

Gestalt psychology or gestaltism (German: Gestalt [ɡəˈʃtalt] "shape, form") is a theory of mind of the Berlin School of experimental psychology. Gestalt psychology tries to understand the laws of our ability to acquire and maintain meaningful perceptions in an apparently chaotic world. The central principle of gestalt psychology is that the mind forms a global whole with self-organizing tendencies.

This principle maintains that when the human mind (perceptual system) forms a percept or gestalt, the whole has a reality of its own, independent of the parts. The original famous phrase of Gestalt psychologist Kurt Koffka, "The whole is other than the sum of the parts" is often incorrectly translated as "The whole is greater than the sum of its parts" and thus used when explaining gestalt theory, and further incorrectly applied to systems theory. Koffka did not like the translation. He firmly corrected students who replaced "other" with "greater". "This is not a principle of addition" he said. The whole has an independent existence.

Phenomenon

A phenomenon (Greek: φαινόμενoν, phainomenon, from the verb φαίνειν, phainein, to show, shine, appear, to be manifest or manifest itself, plural phenomena), is any thing which manifests itself. Phenomena are often, but not always, understood as "things that appear" or "experiences" for a sentient being, or in principle may be so.

The term came into its modern philosophical usage through Immanuel Kant, who contrasted it with the noumenon. In contrast to a phenomenon, a noumenon is not directly accessible to observation. Kant was heavily influenced by Leibniz in this part of his philosophy, in which phenomenon and noumenon serve as interrelated technical terms.

Modern philosophical usage

In modern philosophical use, the term 'phenomena' has come to mean 'what is experienced is the basis of reality'. In Immanuel Kant's Inaugural Dissertation, On the Form and Principles of the Sensible and Intelligible World (1770), Kant theorizes that the human mind is restricted to the logical world and thus can only interpret and understand occurrences according to their physical appearances. He wrote that humans could infer only as much as their senses allowed, but not experience the actual object itself. Thus, the term phenomenon refers to any incident deserving of inquiry and investigation, especially events that are particularly unusual or of distinctive importance. According to The Columbia Encyclopedia, "Modern philosophers have used 'phenomenon' to designate what is apprehended before judgment is applied." This may not be possible if observation is theory laden.

Persistence of vision

Persistence of vision refers to the optical illusion whereby multiple discrete images blend into a single image in the human mind and believed to be the explanation for motion perception in cinema and animated films. Like other illusions of visual perception, it is produced by certain characteristics of the visual system.

History

Narrowly defined, the theory of persistence of vision is the belief that human perception of motion (brain centered) is the result of persistence of vision (eye centered). That version of the theory was disproved in 1912 by Wertheimer but persists in many citations in many classic and modern film-theory texts. A more plausible theory to explain motion perception (at least on a descriptive level) are two distinct perceptual illusions: phi phenomenon and beta movement.

A visual form of memory known as iconic memory has been described as the cause of this phenomenon. Although psychologists and physiologists have rejected the relevance of this theory to film viewership, film academics and theorists generally have not. Some scientists nowadays consider the entire theory a myth.

LED display

An LED display is a flat panel display, which uses an array of light-emitting diodes as pixels for a video display. Their brightness allows them to be used outdoors in store signs and billboards, and in recent years they have also become commonly used in destination signs on public transport vehicles. LED displays are capable of providing general illumination in addition to visual display, as when used for stage lighting or other decorative (as opposed to informational) purposes.

History

The first true all-LED flat panel television screen was possibly developed, demonstrated and documented by James P. Mitchell in 1977. The modular, scalable display was initially designed with hundreds of MV50 LEDs and a newly available transistor-transistor logic memory addressing circuit from Texas Instruments. The ¼-inch thin flat panel prototype and the scientific paper were displayed at the 29th ISEF expo in Washington D.C. in May 1978. It received awards by NASA and General Motors Corporation. A liquid crystal display (LCD) matrix design was also cited in the LED paper as an alternative x-y scan technology and as a future alternate television display method. Additional recognition was provided by Westinghouse Educational Foundation "Honors Group" and the concept prototype was also a selected scientific paper at the Iowa Academy of Science of the University of Northern Iowa. The replacement of the 70 year+ high-voltage analog system (cathode-ray tube technology) with a digital x-y scan system has been a significant achievement. Displacement of the electromagnetic scan systems included the removal of inductive deflection, electron beam and color convergence circuits. The digital x-y scan system has helped the modern television to “collapse” into its current thin form factor.