Thursday, March 29, 2007

Ice Age

An ice age is a stage of long-term slump in the temperature of Earth's climate, resulting in an extension of the continental ice sheets, polar ice sheets and mountain glaciers. Glaciological, ice age is often used to mean a period of ice sheets in the northern and southern hemispheres; by this description we are still in an ice. More colloquially, when speaking of the last few million years, ice age is used to pass on to colder periods with wide ice sheets over the North American and European continents: in this sense, the last ice age ended about 10,000 years ago. This article will use the term ice age in the previous, glaciological, sense; and use the term 'glacial periods' for colder periods during ice ages and 'interglacial' for the heater periods.

During the last few million years, there have been many hostile periods, going on initially at 40,000-year frequency but more freshly at 100,000-year frequencies. These are the best deliberate. There have been four main ice ages in the advance history.

Origin of ice age theory

The idea that, in the past, glaciers had been far wider was folk knowledge in some alpine regions of Europe. No single person made-up the idea. Between 1825 and 1833, Jean de Charpentier assembled verification in support of this idea. In 1836 Charpentier influenced Louis Agassiz of the theory, and Agassiz published it in his book √Čtude sur les glaciers of 1840.

At this near the beginning stage of knowledge, what were being deliberate were the glacial periods within the past few hundred thousand years, during the present ice age. The far previous ice ages' very survival was unsuspected.

Sunday, March 25, 2007

Telephone

The telephone or phone (Greek: tele = far away and phone = voice) is a telecommunications device to transmits and receives sound (most commonly voice and speech) through great distances. Most telephones function by means of electric signals over a complex public switched telephone network of equipment which allows almost any phone user to speak to almost any other.
Until relatively recently the word telephone could generally be assumed to refer to a landline phone. Now, cordless telephones and cell phones have become sufficiently common that no such presumption can be made. There are four principal means by which telephone signals are transmitted: throughout a traditional landline which uses physical dedicated wire connections; wireless or Radiotelephony, which transmits messages using either analog or digital radio signals; satellite telephones which bounce signals off of telecommunications satelites; and voice over internet protocol (VOIP) telephones, which use broadband internet cables.
The electric telephone is recognized to various inventors. The actual history is a subject of complex dispute. Among others Antonio Meucci, Philip Reis, and Alexander Graham Bell are all credited with inventing.

Tuesday, March 20, 2007

Film

Film is a term that encompasses motion pictures as individual projects, as well as the field in general. The source of the name comes from the fact that photographic film (also called filmstock) has historically been the main medium for recording and displaying motion pictures. Many other terms exist — motion pictures, the silver screen, photoplays, picture shows, flicks — and most commonly movies. Academics and the English-speaking international society prefer to use film or "cinema", due to the colloquial nature of these other terms.
Films are created by recording actual people and objects with cameras, or by creating them using animation techniques and/or special effects. They include a series of individual frames, but when these images are shown quickly in succession, the illusion of motion is given to the viewer. Flickering between frames is not seen due to an effect known as persistence of vision — whereby the eye retains a visual image for a fraction of a second after the source has been removed. Perhaps of more relevance is what causes the perception of motion — a psychological effect known as beta movement.

Wednesday, March 14, 2007

Beauty

Beauty in nature is a general theme in modern life and in art, and books emphasizing beauty in nature fill large sections of libraries and bookstores. That nature has been depicted and famous by so much art, photography, poetry and other literature shows the strength with which many people associate nature and beauty. Why this association exists, and what the association consists of, is studied by the branch of philosophy called aesthetics. Beyond certain basic characteristics that many philosophers agree about to explain what is seen as beautiful, the opinions are almost endless.Many scientists, who study nature in more specific and organized ways, also share the conviction that nature is beautiful; the French mathematician, Jules Henri Poincaré (1854-1912) said:
The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.
If nature were not beautiful, it would not be worth knowing, and if nature were not worth meaningful, life would not be worth living. Of course I do not here speak of that beauty which strikes the senses, the beauty of character and of appearance; not that I undervalue such beauty, far from it, but it has not anything to do with science; I mean that profounder beauty which comes from the harmonious order of the parts and which a pure intelligence can grasp.
A general classical idea of beautiful art involves the word mimesis, the imitation of nature. Also in the realm of ideas about beauty in nature is that the perfect is indirect through symmetry, equal division, and other perfect mathematical forms and notions.

Friday, March 09, 2007

Coma

In medicine, a coma (from the Greek koma, meaning deep sleep) is a profound state of unconsciousness. A comatose patient cannot be awakened, fails to respond in general to pain or light, does not contain sleep-wake cycles, and does not take voluntary actions. Coma may result from a variety of conditions, including intoxication, metabolic abnormalities, central nervous system diseases, acute neurologic injuries such as stroke, and hypoxia. It may also be intentionally induced by pharmaceutical agents in order to preserve higher brain function following another form of brain trauma.

Distinctive phases of coma
Within coma itself, there are some categories that describe the severity of impairment. Contrary to popular belief, a patient in a comatose state does not always lay still and quiet. They may talk, walk, and perform other functions that may occasionally appear to be conscious acts, yet are not.
Two scales of measurement regularly used in TBI diagnosis to determine the phase of coma are the Glasgow Coma Scale and the Ranchos Los Amigos Scale. The GCS is a simple 15-point scale used by medical professionals to assess severity of neurologic trauma, and establish a prognosis. The RLAS is a more complex scale that describes up to eight separate levels of coma, and is often used in the first few weeks or months of coma while the patient is under nearer observation, and when shifts between levels are more frequent.

Monday, March 05, 2007

Language school

A language school is a place of education where one can study a foreign language. In most cases, classes at a language school are geared towards, but not limited to, talkative competence in a foreign language. Language learning in such schools usually supplements formal education or experience in a foreign language.
Students vary generally by, among other factors, age, educational background and work experience, as well as language ability. Teachers are likely to possess native fluency or acquired comptence in their target languages; formal qualifications to become a language teacher, however, vary by school, region or country.

Thursday, March 01, 2007

Gemstone

A gemstone is prized particularly for great beauty or perfection so appearance is almost always the most significant attribute of gemstones. Characteristics that make a stone beautiful or attractive are colour, unusual optical phenomena within the stone, an exciting inclusion such as a fossil, rarity, and sometimes the form of the natural crystal. Diamond is prized very much as a gemstone since it is the hardest naturally occurring substance known and is able to reflect light with fire and sparkle when faceted. However, diamonds are far from rare with millions of carats mined each year.
Traditionally, general gemstones were classified into precious stones (cardinal gems) and semi-precious stones. The former class was largely determined by a history of ecclesiastical, devotional or ceremonial use and rarity. Only five types of gemstones were considered precious: diamond, ruby, sapphire, emerald, and amethyst. In current usage by gemologists, all gems are considered precious, although four of the five original "cardinal gems" (excluding the now-common amethyst) are typically—but not always—the most valuable.
Rare or unusual gemstones, usually meant to include those gemstones which occur so infrequently in gem quality that they are only just known except to connoisseurs, include andalusite, axinite, cassiterite, clinohumite and iolite.