deep reflector
41High-gain antenna — The high gain antenna (HGA) is an antenna with a focused, narrow radiowave beam width. This narrow beam width allows more precise targeting of the radio signal also known as a directional antenna. Most commonly referred to during space missions,… …
42Bombe — In the history of cryptography, the Bombe was an electromechanical device used by British cryptologists to help break German Enigma machine signals during World War II. The bombe was designed by Alan Turing, with an important refinement suggested …
43Isaac Roberts — (January 27 1829 July 17 1904) was a Welsh astronomer who was a pioneer in photography of nebulae. He was a member of the Liverpool Astronomical Society in England and was a fellow of the Royal Geological Society. Roberts was also awarded the… …
44Microwave transmission — The atmospheric attenuation of microwaves in dry air with a precipitable water vapor level of 0.001 mm. The downward spikes in the graph correspond to frequencies at which microwaves are absorbed more strongly, such as by oxygen molecules… …
45cephalopod — /sef euh leuh pod /, n. 1. any mollusk of the class Cephalopoda, having tentacles attached to the head, including the cuttlefish, squid, and octopus. adj. 2. Also, cephalopodic, cephalopodous /sef euh lop euh deuhs/. belonging or pertaining to… …
46physical science, principles of — Introduction the procedures and concepts employed by those who study the inorganic world. physical science, like all the natural sciences, is concerned with describing and relating to one another those experiences of the surrounding… …
47Characters of Shakespear's Plays —   …
48Hubble Space Telescope — Infobox Space telescope name = Hubble Space Telescope (HST) caption = The Hubble Space Telescope as seen from Space Shuttle Discovery during its second servicing mission (STS 82) organization = NASAESASTScI alt names = nssdc id =… …
49building construction — Techniques and industry involved in the assembly and erection of structures. Early humans built primarily for shelter, using simple methods. Building materials came from the land, and fabrication was dictated by the limits of the materials and… …
50Enriched uranium — Proportions of uranium 238 (blue) and uranium 235 (red) found naturally versus enriched grades Enriched uranium is a kind of uranium in which the percent composition of uranium 235 has been increased through the process of isotope separation.… …
