deep reflector
121Perkins Observatory — is an astronomical observatory in Delaware, Ohio. It is owned and operated by Ohio Wesleyan University.Early HistoryThe observatory is named for Hiram Perkins, a professor of mathematics and astronomy at the Ohio Wesleyan University in Delaware,… …
122Peaceful nuclear explosions — (PNEs) are nuclear explosions conducted for non military purposes, such as activities related to economic development including the creation of canals. During the 1960s and 1970s, both the United States and the Soviet Union conducted a number of… …
123Maritime history of California — History of California This article is part of a series Timeline …
124Nuclear safety — covers the actions taken to prevent nuclear and radiation accidents or to limit their consequences. This covers nuclear power plants as well as all other nuclear facilities, the transportation of nuclear materials, and the use and storage of… …
125Passive margin — A passive margin is the transition between oceanic and continental crust which is not an active plate margin. It is constructed by sedimentation above an ancient rift, now marked by transitional crust. Continental rifting creates new ocean basins …
126Undersea Kingdom — Infobox Film name = Undersea Kingdom director =B. Reeves Eason Joseph Kane producer =Nat Levine writer =Tracy Knight John Rathmell Maurice Geraghty Oliver Drake starring =Ray Corrigan Lois Wilde Monte Blue William Farnum C. Montague Shaw Lee Van… …
127Light tube — This article is about light tubes used for the illumination of buildings. For other uses of the phrase light tubes , see Light tube (disambiguation). Light tubes Light tubes or light pipes are used for transporting or distributing natural or… …
128Underground nuclear testing — Preparation for an underground nuclear test at the Nevada Test Site in the 1990s. Nuclear weapons …
