Incandescent light bulbAn incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament that is heated until it glows. The filament is enclosed in a glass bulb that is filled with vacuum or inert gas to protect the filament from oxidation. Current is supplied to the filament by terminals or wires embedded in the glass. A bulb socket provides mechanical support and electrical connections. Incandescent bulbs are manufactured in a wide range of sizes, light output, and voltage ratings, from 1.
PhotodetectorPhotodetectors, also called photosensors, are sensors of light or other electromagnetic radiation. There is a wide variety of photodetectors which may be classified by mechanism of detection, such as photoelectric or photochemical effects, or by various performance metrics, such as spectral response. Semiconductor-based photodetectors typically photo detector have a p–n junction that converts light photons into current. The absorbed photons make electron–hole pairs in the depletion region.
Railroad chronometerA railroad chronometer or railroad standard watch is a specialized timepiece that once was crucial for safe and correct operation of trains in many countries. A system of timetable and train order, which relied on highly accurate timekeeping, was used to ensure that two trains could not be on the same stretch of track at the same time. Regulations of the watches used by critical personnel on the railroads (engineer, conductor, switch yard controllers, etc.) were specified almost from the beginning of widespread railroad use in the 1850s and 1860s.
5K resolution5K resolution refers to display formats with a horizontal resolution of around 5,000 pixels. The most common 5K resolution is , which has an aspect ratio of with around 14.7 million pixels (just over seven times as many pixels as 1080p Full HD), with exactly twice the linear resolution of 1440p and four times that of 720p. This resolution is typically used in computer monitors to achieve a higher pixel density, and is not a standard format in digital television and digital cinematography, which feature 4K resolutions and 8K resolutions.
Coupon-eligible converter boxA coupon-eligible converter box (CECB) was a digital television adapter that met eligibility specifications for subsidy "coupons" from the United States government. The subsidy program was enacted to provide terrestrial television viewers with an affordable way to continue receiving free digital terrestrial television services after the nation's television service transitioned to digital transmission and analog transmissions ceased.
Level (video games)In video games, a level (also referred to as a map, stage, or round in some older games) is any space available to the player during the course of completion of an objective. Video game levels generally have progressively increasing difficulty to appeal to players with different skill levels. Each level may present new concepts and challenges to keep a player's interest high. In games with linear progression, levels are areas of a larger world, such as Green Hill Zone. Games may also feature interconnected levels, representing locations.
History of longitudeThe history of longitude describes the centuries-long effort by astronomers, cartographers and navigators to discover a means of determining the longitude of any given place on Earth. The measurement of longitude is important to both cartography and navigation. In particular, for safe ocean navigation, knowledge of both latitude and longitude is required, however latitude can be determined with good accuracy with local astronomical observations.
