accurate measurement
41Julian year — (a) the average length of the year in the Julian calendar, equal to exactly 365.25 days. See year2. Astronomers use Julian years in computing the motions of planets and other bodies of the Solar System. This simplifies their calculations, but… …
42twip — a unit of distance used in computer graphics for high resolution control of the elements of an image. One twip is equal to 1/1440 inch, about 17.639 micrometers, or 0.070 556 kyu. Twip is an acronym for twentieth of a point, which is accurate… …
43Clock — For other uses, see Clock (disambiguation). Timepiece redirects here. For the Kenny Rogers album, see Timepiece (album). Platform clock at King s Cross railway station, London …
44Vacuum — This article is about empty physical space or the absence of matter. For other uses, see Vacuum (disambiguation). Free space redirects here. For other uses, see Free space (disambiguation). Pump to demonstrate vacuum In everyday usage, vacuum is… …
45Cosmic distance ladder — * Light green boxes: Technique applicable to star forming galaxies. * Light blue boxes: Technique applicable to Population II galaxies. * Light Purple boxes: Geometric distance technique. * Light Red box: The planetary nebula luminosity function… …
46mass spectrometry — or mass spectroscopy Analytic technique by which chemical substances are identified by sorting gaseous ions by mass using electric and magnetic fields. A mass spectrometer uses electrical means to detect the sorted ions, while a mass spectrograph …
47Driller's depth — The original depth recorded while drilling an oil or gas well is known as the Driller s Depth. Contents 1 The Problem 1.1 Measurement of Driller s Depth 1.2 Measuring drill string length 1.2.1 …
48Norden bombsight — The Norden bombsight at the Computer History Museum in Mountain View, California. This example does not have the associated autopilot attached …
49Investment management — is the professional management of various securities (shares, bonds etc.) and assets (e.g., real estate), to meet specified investment goals for the benefit of the investors. Investors may be institutions (insurance companies, pension funds,… …
50Tonometry — In music, a tonometer is an instrument used to determine the pitch or vibration rate of tones, such as a tuning fork. Tonometry is the measurement of tension or pressure [http://www.mercksource.org/pp/us/cns/cns hl… …
