Sunglasses are a kind of visual correction aid, variously termed spectacles or glasses, which feature lenses that are coloured or darkened to screen out strong light from the eyes.
Many people find direct sunlight too bright to be comfortable, particularly when reading from paper on which the sun directly shines. In outdoor activities like skiing and flying, the eye can receive more light than usual. It has been recommended to wear these kind of glasses on sunny days to protect the eyes from ultraviolet radiation, which can lead to the development of a cataract. Sunglasses have also been linked with celebrities and film actors mainly due to the desire to mask identity, but in part due to the lighting involved in production being typically stronger than natural light and uncomfortable to the naked eye.
Augusto Pinochet sits with sunglasses in the front of the Chilean JuntaContents


The materials definition of a glass is a uniform amorphous solid material, frequently produced when a suitably viscous molten material cools very fast to below its glass transition temperature, thereby not giving enough time for a regular crystal lattice to form. A simple example is when table sugar is melted and cooled quickly by dumping the liquid sugar onto a cold surface. The resultant solid is amorphous, not crystaline like the sugar was initially, which can be seen in its conchoidal fracture.
The word glass comes from Latin glacies (ice) and corresponds to German Glas, M.E. glas, A.S. glaes. Germanic tribes used the word glaes to describe amber, recorded by Roman historians as glaesum. Anglo-Saxons used the word glaer for amber.
The remainder of this article will be concerned with a specific type of glass—the silica-based glasses in common use as a building, container or decorative material.
In its pure form, glass is a transparent, comparatively strong, hard-wearing, essentially inert, and biologically inactive material which can be created with very smooth and impervious surfaces. These desirable properties lead to a great many uses of glass. Glass is, however, brittle and will break into sharp shards. These properties can be modified, or even changed completely, with the addition of other compounds or heat treatment.
Common glass is frequently amorphous silicon dioxide (SiO2), which is the same chemical compound found in quartz, or in its polycrystalline form, sand.


A rocket is a vehicle, missile or aircraft which obtains thrust by the reaction to the ejection of fast moving exhaust gas from within a rocket engine. Often the term rocket is also used to denote a rocket engine.
In military terminology, a rocket usually uses solid propellant and is unguided. These rockets can be fired by ground-attack aircraft at fixed targets such as buildings, or can be launched by ground forces at other ground targets. During the Vietnam era, there were also air launched unguided rockets that carried a nuclear payload intended to attack aircraft formations in flight. A missile, by contrast, can use either solid or liquid propellant, and has a guidance system. This distinction usually applies only in the case of weapons, though, and not to civilian or orbital launch vehicles.
In all rockets the exhaust is created from propellant which is carried within the rocket prior to its release. Rocket thrust is due to accelerating the exhaust gases .There are many dissimilar types of rockets, and a comprehensive list can be found in spacecraft propulsion- they range in size from tiny models that can be purchased at a hobby store, to the enormous Saturn V used for the Apollo program.
Rockets are used to accelerate, change orbits, de-orbit for landing, for the whole landing if there is no atmosphere, and sometimes to soften a parachute landing immediately before touchdown.

Slavonian Grebe

The Slavonian Grebe, Podiceps auritus , is a associate of the grebe family of water birds. It is known in North America as the Horned Grebe.
It is a small grebe at 31-38 cm (12"-15") long with a 46-55 cm wingspan. It is duck-like, with scarlet eyes, and a small, straight black bill tipped with white during the summer. It rides high in the water.
Unmistakable in summer, the male's nesting plumage includes a black head with brown-yellow puffy earlike tufts along the sides of its face, and a red neck.
Slavonian Grebe breeds in vegetated areas of freshwater lakes across Europe and Asia. It also breeds in remote inland parts of the United States and much of Canada. Most birds migrate in winter to the coast. In winter, this small grebe is mainly white with a sharply defined black cap, and resembles a small Red-necked Grebe.
Like all grebes, it nests on the water's edge, since its legs are set very far back and it cannot walk well. generally two eggs are laid, and the striped young are sometimes carried on the adult's back.
Slavonian Grebe is an outstanding swimmer and diver, and pursues its fish prey underwater.
During breeding, the male's call is heard as an odd, striking series of loud croaks and chattering notes followed by prolonged shrieks.
Folk names of this bird comprise Devil-diver, hell-diver, pink-eyed diver, and water witch.


Silk, known as pattu, has a long history in India and is generally produced today. Historically silk was used by the upper classes, while cotton was used by the poorer classes. Today silk is mostly produced in Kanchipuram, Dharmavaram, Mysore, etc. in South India and Banaras in the North. "Murshidabad silk", well-known from historical times, is mostly produced in Malda and Murshidabad district of West Bengal and woven with hand looms in Birbhum and Murshidabad district. The silk from Kanchi is mainly well-known for its classic designs and enduring quality. The silk is traditionally hand-woven and hand-dyed and regularly also has silver threads woven into the cloth. Most of this silk is used to make saris. The saris usually are very expensive and vibrant in color. Garments made from silk form an integral part of Indian weddings and other celebrations. In the northeastern state of Assam, three different types of silk are produced, together called Assam silk: Muga, Eri and Pat silk. Muga, the golden silk, and Eri are produced by silkworms that are native only to Assam. The heritage of silk rearing and weaving is very old and continues today particularly with the production of Muga and Pat riha and mekhela sador, the three-piece silk saris woven with traditional motifs.


A rainbow is an optical and meteorological phenomenon that causes a almost continuous spectrum of light to become visible in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere. It takes the form of a multicoloured arc, with red on the outside and violet on the inside. More not often, a double rainbow is seen, which includes a second, fainter arc with colours in the opposite order, that is, with violet on the outside and red on the inside.
Even though a rainbow spans a continuous spectrum of colours, conventionally the full sequence of colours is most commonly cited and remembered as red, orange, yellow, green, blue, indigo and violet.

Computer network

A computer network is two or more computers linked together using a telecommunication system for the purpose of communicating and sharing resources. Experts in the field of networking debate whether two computers that are associated together using some form of communications medium comprise a network. Therefore, some works state that a network requires three connected computers. For example, "Telecommunications: Glossary of Telecommunication Terms" states that a computer network is "A network of data processing nodes that are consistent for the purpose of data communication", the term "network" being defined in the same document as "An interconnection of three or more communicating entities". A computer connected to a non-computing device (e.g., networked to a printer via an Ethernet link) may also correspond to a computer network, although this article does not address this configuration.
This article uses the definition which requires two or more computers to be linked together to form a network. The same basic functions are normally present in this case as with larger numbers of connected computers.