Vedas

The Vedas (/ˈveɪdəz, ˈviː-/;Sanskrit: वेद véda, "knowledge") are a large body of texts originating in ancient India. Composed in Vedic Sanskrit, the texts constitute the oldest layer of Sanskrit literature and the oldest scriptures of Hinduism. Hindus consider the Vedas to be apauruṣeya, which means "not of a man, superhuman" and "impersonal, authorless".

Vedas are also called śruti ("what is heard") literature, distinguishing them from other religious texts, which are called smṛti ("what is remembered"). The Veda, for orthodox Indian theologians, are considered revelations seen by ancient sages after intense meditation, and texts that have been more carefully preserved since ancient times. In the Hindu Epic the Mahabharata, the creation of Vedas is credited to Brahma. The Vedic hymns themselves assert that they were skillfully created by Rishis (sages), after inspired creativity, just as a carpenter builds a chariot.

There are four Vedas: the Rigveda, the Yajurveda, the Samaveda and the Atharvaveda. Each Veda has been subclassified into four major text types – the Samhitas (mantras and benedictions), the Aranyakas (text on rituals, ceremonies, sacrifices and symbolic-sacrifices), the Brahmanas (commentaries on rituals, ceremonies and sacrifices), and the Upanishads (text discussing meditation, philosophy and spiritual knowledge). Some scholars add a fifth category – the Upasanas (worship).

Vedic (disambiguation)

Vedic may refer to:

Differential interference contrast microscopy

Differential interference contrast (DIC) microscopy, also known as Nomarski interference contrast (NIC) or Nomarski microscopy, is an optical microscopy technique used to enhance the contrast in unstained, transparent samples. DIC works on the principle of interferometry to gain information about the optical path length of the sample, to see otherwise invisible features. A relatively complex optical system produces an image with the object appearing black to white on a grey background. This image is similar to that obtained by phase contrast microscopy but without the bright diffraction halo. The technique was developed by Georges Nomarski.

DIC works by separating a polarized light source into two orthogonally polarized mutually coherent parts which are spatially displaced (sheared) at the sample plane, and recombined before observation. The interference of the two parts at recombination is sensitive to their optical path difference (i.e. the product of refractive index and geometric path length). Adding an adjustable offset phase determining the interference at zero optical path difference in the sample, the contrast is proportional to the path length gradient along the shear direction, giving the appearance of a three-dimensional physical relief corresponding to the variation of optical density of the sample, emphasising lines and edges though not providing a topographically accurate image.

Viscosity

The viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress. For liquids, it corresponds to the informal concept of "thickness". For example, honey has a much higher viscosity than water.

Viscosity is a property arising from collisions between neighboring particles in a fluid that are moving at different velocities. When the fluid is forced through a tube, the particles which compose the fluid generally move more quickly near the tube's axis and more slowly near its walls: therefore some stress, (such as a pressure difference between the two ends of the tube), is needed to overcome the friction between particle layers to keep the fluid moving. For the same velocity pattern, the stress required is proportional to the fluid's viscosity.

A fluid that has no resistance to shear stress is known as an ideal or inviscid fluid. Zero viscosity is observed only at very low temperatures in superfluids. Otherwise, all fluids have positive viscosity, and are technically said to be viscous or viscid. In common parlance however, a liquid is said to be viscous if its viscosity is substantially greater than that of water; and may be described as mobile if the viscosity is noticeably less than water. A fluid with a relatively high viscosity, for example, pitch, may appear to be a solid.

Viscosity (programming)

In object oriented programming, viscosity refers to the ease at which a developer can add design-preserving code to a system. If it is easier to add a hack than it is to add code that fits into the program's design, then the system has high viscosity. If it is easy to add new code to the program while maintaining the design, then the program has low viscosity.

The name is a metaphor for viscosity in liquids.

See also

Viscosity printing

Viscosity printing is a multi-color printmaking technique that incorporates principles of relief printing and intaglio printing. It was pioneered by Stanley William Hayter.

The process uses the principle of viscosity to print multiple colors of ink from a single plate, rather than relying upon multiple plates for color separation. It is a fine art printmaking technique, making original prints in limited editions, as it is slow and allows too much variation between proofs to make large editions feasible. Color viscosity printing is among the latest developments in intaglio printmaking. Stanley William Hayter developed it during the late 1960s in Paris.

Intaglio

There are a number of different types of original print methods to be aware of. Intaglio prints: for example a dollar bill—bills and most stamps are engraved in metal plates and are printed after a viscous ink (about the consistency of oil paint) is forced into grooves, scratches, etched lines or indentations. The polished surface is then wiped clean using newsprint and tarlatan, leaving ink only below plate level. The plate is then covered with a dampened paper and felt blankets. It is run through the press where great pressure (approximately 8 tons to the square inch) pushes the dampened paper down into the engraved or etched grooves to pick up ink. In other words, in intaglio we see printed what is below the surface of the plate and the ink is now embossed on the paper. Among the greatest masters of engraving and etching are Albrecht Dürer, Hans Holbien, Rembrandt, Goya, and Picasso.