will be accurate to within
41Hill sphere — A Hill sphere is, roughly, the volume around an astronomical body (such as a planet) where it dominates in attraction of satellites to that body, rather than to a larger body (such as a star) which it orbits. Thus, for a planet to retain a moon,… …
42StarFire (navigation system) — StarFire is a wide area differential GPS developed by John Deere s NavCom and Precision Farming groups. StarFire broadcasts additional correction information over satellite L band frequencies around the world, allowing a StarFire equipped… …
43History of timekeeping devices — For thousands of years, devices have been used to measure and keep track of time. The current sexagesimal system of time measurement dates to approximately 2000 BC, in Sumer. The Ancient Egyptians divided the day into two 12 hour periods, and… …
44Magick — For other uses, see Magic (disambiguation). Thelema Category:Thelema Core topics The Book of the Law …
45De (Chinese) — Taoism portal Taoism …
46Mining feasibility study — A mining feasibility study is an evaluation of a proposed mining project to determine whether the mineral resource can be mined economically. There are three types of feasibility study used in mining, order of magnitude, preliminary feasibility… …
47Leap year — A leap year (or intercalary year) is a year containing one or more extra days (or, in the case of lunisolar calendars, an extra month) in order to keep the calendar year synchronised with the astronomical or seasonal year. For example, in the… …
48Morgenthau Plan — The Morgenthau Plan showing the planned partitioning of Germany into a North State, a South State, and an International zone. Areas in grey are areas intended for control by France, Poland and the USSR …
49Benchmarking (geolocating) — Benchmarking is an activity in which individuals or teams of participants go out and find benchmarks (also known as geodetic control points ). They typically then log their finds online. Like geocaching, the activity has mainly become popular in… …
50Marine chronometer — Breguet twin barrel box chronometer. Classification Clock Industry Transportation …
