center holes
51Doughnut — For other uses, see Doughnut (disambiguation). A glazed doughnut …
52Hillsboro, Oregon — Infobox Settlement official name = Hillsboro, Oregon settlement type = City nickname = The Hub City motto = imagesize = 240px image caption = Downtown with Mount Hood and Tuality Hospital in the background. image established date = 1876… …
53Compact star — In astronomy, the term compact star (sometimes compact object) is used to refer collectively to white dwarfs, neutron stars, other exotic dense stars, and black holes. These objects are all small for their mass. The term compact star is often… …
54ICF Bogie — is a conventional railway bogie used on the majority of Indian Railway main line passenger coaches. The design of the bogie was developed by ICF (Integral Coach Factory), Perumbur, India in collaboration with the Swiss Car Elevator Manufacturing… …
55Movie projector — This article is concerned with technical aspects of moving film projection. For non film movie projection, see digital cinema. For historical aspects, see the article history of cinema. 35 mm movie projector in operation …
56Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
57Galaxy — This article is about the astronomical structure. For other uses, see Galaxy (disambiguation). NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 55,000 light years in diameter and approximately 60 million light… …
58Introduction to general relativity — General relativity (GR) is a theory of gravitation that was developed by Albert Einstein between 1907 and 1915. According to general relativity, the observed gravitational attraction between masses results from the warping of space and time by… …
59Episode list of The Universe (TV series) — This is a list of the currently released and yet to be released episodes of The History Channel s television Series The Universe .eason One Episodes* Episode 1 Secrets of the Sun It is a fireball in the sky, a bubbling, boiling, kinetic sphere of …
60Hubble 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 =… …
