A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms (oscilloscope), pictures, radar targets, or other phenomena. A CRT on a television set is commonly called a picture tube. CRTs have also been used as memory devices, in which case the screen is not intended to be visible to an observer. The term cathode ray was used to describe electron beams when they were first discovered, before it was understood that what was emitted from the cathode was a beam of electrons.
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviolet, and infrared light. Because light is an electromagnetic wave, other forms of electromagnetic radiation such as X-rays, microwaves, and radio waves exhibit similar properties.
Derived from the Greek word for '5', and "domino", a pentomino is a polyomino of order 5, that is, a polygon in the plane made of 5 equal-sized squares connected edge-to-edge. When rotations and reflections are not considered to be distinct shapes, there are 12 different free pentominoes. When reflections are considered distinct, there are 18 one-sided pentominoes. When rotations are also considered distinct, there are 63 fixed pentominoes.
In 3-D computer graphics, ray tracing is a technique for modeling light transport for use in a wide variety of rendering algorithms for generating digital images.
The Vectrex is a vector display-based home video game console - the only one ever designed and released for the home market, that was developed by Smith Engineering and manufactured and sold by General Consumer Electronics. It was first released for the North America market in November 1982 and then Europe and Japan in 1983. Originally produced by General Consumer Electronics, it was later licensed to Milton Bradley after they acquired the company. Bandai released the system in Japan.
Cluedo, known as Clue in North America, is a murder mystery game for three to six players that was devised in 1943 by British board game designer Anthony E. Pratt. The game was first manufactured by Waddingtons in the United Kingdom in 1949. Since then, it has been relaunched and updated several times, and it is currently owned and published by the American game and toy company Hasbro.
Sir Joseph John Thomson was a British physicist and Nobel Laureate in Physics, credited with the discovery of the electron, the first subatomic particle to be found.
Battleship is a strategy type guessing game for two players. It is played on ruled grids on which each player's fleet of warships are marked. The locations of the fleets are concealed from the other player. Players alternate turns calling "shots" at the other player's ships, and the objective of the game is to destroy the opposing player's fleet.
The Geiger–Marsden experiments were a landmark series of experiments by which scientists learned that every atom has a nucleus where all of its positive charge and most of its mass is concentrated. They deduced this after measuring how an alpha particle beam is scattered when it strikes a thin metal foil. The experiments were performed between 1908 and 1913 by Hans Geiger and Ernest Marsden under the direction of Ernest Rutherford at the Physical Laboratories of the University of Manchester.
Ray casting is the methodological basis for 3D CAD/CAM solid modeling and image rendering. It is essentially the same as ray tracing for computer graphics where virtual light rays are "cast" or "traced" on their path from the focal point of a camera through each pixel in the camera sensor to determine what is visible along the ray in the 3D scene. The term "Ray Casting" was introduced by Scott Roth while at the General Motors Research Labs from 1978–1980. His paper, "Ray Casting for Modeling Solids", describes modeled solid objects by combining primitive solids, such as blocks and cylinders, using the set operators union (+), intersection (&), and difference (-). The general idea of using these binary operators for solid modeling is largely due to Voelcker and Requicha's geometric modelling group at the University of Rochester. See solid modeling for a broad overview of solid modeling methods. This figure on the right shows a U-Joint modeled from cylinders and blocks in a binary tree using Roth's ray casting system in 1979.
Rush Hour is a sliding block puzzle invented by Nob Yoshigahara in the 1970s. It was first sold in the United States in 1996. It is now being manufactured by ThinkFun.
In quantum physics, the Stern–Gerlach experiment demonstrated that the spatial orientation of angular momentum is quantized. Thus an atomic-scale system was shown to have intrinsically quantum properties. In the original experiment, silver atoms were sent through a spatially-varying magnetic field, which deflected them before they struck a detector screen, such as a glass slide. Particles with non-zero magnetic moment were deflected, owing to the magnetic field gradient, from a straight path. The screen revealed discrete points of accumulation, rather than a continuous distribution, owing to their quantized spin. Historically, this experiment was decisive in convincing physicists of the reality of angular-momentum quantization in all atomic-scale systems.
Arrow keys or cursor movement keys are keys on a computer keyboard that are either programmed or designated to move the cursor in a specified direction.
Waddingtons was a British manufacturer of card and board games. The company was founded by John Waddington of Leeds, England and the manager, actor and playwright Wilson Barrett, under the name Waddingtons Limited. The name was changed in 1905 to John Waddington Limited, then Waddington's House of Games, then Waddington Games, and finally just Waddingtons.
Tutankham is a 1982 arcade video game developed and released by Konami and released by Stern in North America. Named after the Egyptian pharaoh Tutankhamun, the game combines a maze shoot 'em up with light puzzle-solving elements. It debuted at the European ATE and IMA amusement shows in January 1982, before releasing worldwide in Summer 1982. The game was a critical and commercial success and was ported to home systems by Parker Brothers.
Rebound is a two-player sports arcade video game developed by Atari and released in February 1974. In the game, two players each control paddles on either side of a volleyball net, with a ball dropped from the top of the screen. The players bounce the ball back and forth across the net with the goal of scoring points by having the ball reach the bottom or side of the other player's half of the screen, with the trajectory of the ball dependent on where it strikes the paddle. The winner is the first player to reach eleven or fifteen points, depending on the game settings.
Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, α. The symbol for the alpha particle is α or α2+. Because they are identical to helium nuclei, they are also sometimes written as He2+
or 4
2He2+
indicating a helium ion with a +2 charge. Once the ion gains electrons from its environment, the alpha particle becomes a normal helium atom 4
2He.
Kareem Jackson is an American football safety for the Denver Broncos of the National Football League (NFL). He played college football at Alabama. He was drafted by the Houston Texans in the first round of the 2010 NFL Draft.
Cluedo, known as Clue in North America, is a murder mystery-themed multimedia franchise started in 1949 with the manufacture of the Cluedo board game. The franchise has since expanded to film, television game shows, book series, computer games, board game spinoffs, a comic, a play, a musical, jigsaws, card games, and other media.
