angular length
81Insect wing — Original veins and wing posture of a dragonfly. Hoverflies hovering to mate …
82Edinburgh — EDINBURGH, a city, the seat of a university, and the metropolis of the kingdom of Scotland, situated in longitude 3° 10 30 (W.), and latitude 55° 57 29 (N.), about a mile (S. by W.) from Leith, 40 miles (S.S.W.) from Dundee, 42 (E. by N.) from …
83Fourier optics — is the study of classical optics using techniques involving Fourier transforms and can be seen as an extension of the Huygens Fresnel principle. The underlying theorem that light waves can be described as made up of sinusoidal waves, in a manner… …
84Cosmic 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… …
85Introduction to quantum mechanics — This article is an accessible, non technical introduction to the subject. For the main encyclopedia article, see Quantum mechanics. Quantum mechanics …
86Piston motion equations — The motion of a non offset piston connected to a crank through a connecting rod (as would be found in internal combustion engines), can be expressed through several mathematical equations. This article shows how these motion equations are derived …
87Tropical year — A tropical year (also known as a solar year), for general purposes, is the length of time that the Sun takes to return to the same position in the cycle of seasons, as seen from Earth; for example, the time from vernal equinox to vernal equinox,… …
88Fourier transform — Fourier transforms Continuous Fourier transform Fourier series Discrete Fourier transform Discrete time Fourier transform Related transforms The Fourier transform is a mathematical operation that decomposes a function into its constituent… …
89Old quantum theory — Quantum mechanics Uncertainty principle …
90Rotational-vibrational coupling — occurs when the rotation frequency of an object is close to or identical to a natural internal vibration frequency. The animation on the right shows a simple example. The motion depicted in the animation is for the idealized situation that the… …
