number aperture
71gastropod — /gas treuh pod /, n. 1. any mollusk of the class Gastropoda, comprising the snails, whelks, slugs, etc. adj. 2. Also, gastropodous /ga strop euh deuhs/. belonging or pertaining to the gastropods. [1820 30; < NL Gast(e)ropoda a class of mollusks.… …
72photoreception — photoreceptive, adj. /foh toh ri sep sheuhn/, n. the physiological perception of light. [1905 10; PHOTO + RECEPTION] * * * Biological responses to stimulation by light, most often referring to the mechanism of vision. In one celled organisms such …
73radar — /ray dahr/, n. 1. Electronics. a device for determining the presence and location of an object by measuring the time for the echo of a radio wave to return from it and the direction from which it returns. 2. a means or sense of awareness or… …
74Contarex — The Contarex of 1958 1966 Type 35mm SLR camera Lens mount Contarex bayonet Focus lens helical Exposure 24 × 36mm on 35mm film …
75MQ-1 Predator — infobox Aircraft name = MQ 1 Predator type = Remote controlled UAV manufacturer = General Atomics Aeronautical Systems caption = designer = first flight = introduction = retired = status = primary user = United States Air Force more users =… …
76Digital single-lens reflex camera — Nikon D700 full frame (FX) digital SLR camera …
77Steam whistle — A steam whistle is a device used to produce sound with the aid of live steam. Unlike a horn, the sounding mechanism of a whistle contains no moving parts (compare to train horn).The whistle consists of the following main parts, as seen on the… …
78Locations of Half-Life — The Half Life series of video games features many locations set in a dystopian future stemming from the events of the first game, Half Life. These locations are used and referred to throughout the series. The locations, for the most part, are… …
79Iron sight — Sight picture through iron sights of an H K MP5 submachine gun. The annular shroud around the front post sight is aligned with the rear peep sight to ensure the weapon is properly trained. Iron sights are a system of shaped alignment markers… …
80History of radar — The history of radar starts with experiments by Heinrich Hertz in the late 19th century that showed that radio waves were reflected by metallic objects. This possibility was suggested in James Clerk Maxwell s seminal work on electromagnetism.… …
