Loom

A loom is a device used to weave cloth and tapestry. The basic purpose of any loom is to hold the warp threads under tension to facilitate the interweaving of the weft threads. The precise shape of the loom and its mechanics may vary, but the basic function is the same.

Etymology

The word "loom" is derived from the Old English "geloma" formed from ge-(perfective prefix) and loma, a root of unknown origin; this meant utensil or tool or machine of any kind. In 1404 it was used to mean a machine to enable weaving thread into cloth. By 1838 it had gained the meaning of a machine for interlacing thread.

Weaving

Weaving is done by intersecting the longitudinal threads, the warp, i.e. "that which is thrown across", with the transverse threads, the weft, i.e. "that which is woven".

The major components of the loom are the warp beam, heddles, harnesses or shafts (as few as two, four is common, sixteen not unheard of), shuttle, reed and takeup roll. In the loom, yarn processing includes shedding, picking, battening and taking-up operations. These are the principal motions.

Prism

In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. At least two of the flat surfaces must have an angle between them. The exact angles between the surfaces depend on the application. The traditional geometrical shape is that of a triangular prism with a triangular base and rectangular sides, and in colloquial use "prism" usually refers to this type. Some types of optical prism are not in fact in the shape of geometric prisms. Prisms can be made from any material that is transparent to the wavelengths for which they are designed. Typical materials include glass, plastic and fluorite.

A dispersive prism can be used to break light up into its constituent spectral colors (the colors of the rainbow). Furthermore, prisms can be used to reflect light, or to split light into components with different polarizations.

How prisms work

Light changes speed as it moves from one medium to another (for example, from air into the glass of the prism). This speed change causes the light to be refracted and to enter the new medium at a different angle (Huygens principle). The degree of bending of the light's path depends on the angle that the incident beam of light makes with the surface, and on the ratio between the refractive indices of the two media (Snell's law). The refractive index of many materials (such as glass) varies with the wavelength or color of the light used, a phenomenon known as dispersion. This causes light of different colors to be refracted differently and to leave the prism at different angles, creating an effect similar to a rainbow. This can be used to separate a beam of white light into its constituent spectrum of colors. Prisms will generally disperse light over a much larger frequency bandwidth than diffraction gratings, making them useful for broad-spectrum spectroscopy. Furthermore, prisms do not suffer from complications arising from overlapping spectral orders, which all gratings have.

List of Humanx Commonwealth planets

This is a list of the fictional planets in the Humanx Commonwealth series of novels by Alan Dean Foster.

Alaspin

Alaspin has large jungles surrounded by equally large savannas and river plains; its only notable celestial feature is two moons.

Currently the planet has no sentient race; the native race died out, possibly by racial suicide, over 75,000 years ago leaving behind hundreds of ancient, abandoned cities that have proved a source of fascination to modern xeno-archaeologists.

A variety of lifeforms currently live on Alaspin, most notably the Alaspinian minidrag.

Annubis

Annubis is most notable for the fictional Hyperion forests from which the fictional drug bloodhype is manufactured. In an attempt to eradicate the highly addictive and deadly drug, the trees were burned in 545 A.A. and are thought to be completely destroyed.

The planet first appeared in the novel Bloodhype.

Blasusarr

Blasusarr is the homeworld of the AAnn race and is often called the Imperial Home World. Climate is dry and hot, largely desert, the preferred atmospheric conditions of the AAnn. Beyond this, little is known about Blasusarr other than the fact that it is very well-protected by a detection and space defense network. Its capital city, also the capital of the AAnn Empire, is Krrassin.

Prism (disambiguation)

A prism is a transparent optical component with flat surfaces that refract light.

Prism may also refer to:

Science and mathematics

Government

Media and entertainment

Publications

Music