The White Sands National Monument is a U.S. National Monument situated about 25km (15 miles) southwest of Alamogordo in the state of New Mexico. The area is in the mountain-ringed Tularosa Basin valley area and comprises the southern part of a 710km² (275-square mile) field of white sand dunes composed of gypsum crystals.
Gypsum is rarely found in the shape of sand because it is water soluble. generally, rain would dissolve the gypsum and carry it to the sea. Since the Tularosa Basin has no outlet to the sea, rain that dissolves gypsum from the surrounding San Andres and Sacramento Mountains is trapped within the basin and either sinks into the ground or forms shallow pools that next dry out and leave gypsum in a crystalline form called selenite on the surface. During the last ice age a lake called Lake Otero enclosed much of the basin. When it dried out it left a large flat area of selenite crystals which is now the Alkali Flat. Lake Lucero, at the south-west corner of the park, is a dry lake bed at one of the lowest points of the basin that infrequently fills with water.
The ground in the Alkali Flat and along Lake Lucero's shore is covered with selenite crystals which reach lengths of up to three feet. Weather erosion ultimately breaks the crystals into sand-size grains that are carried away by the prevailing winds from the south-west, forming white dunes.
Thursday, March 29, 2007
Monday, March 26, 2007
Personal computer
A personal computer or PC is usually a microcomputer intended to be used by one person at a time, and suitable for general purpose tasks such as word processing, programming, sending messages or digital documents (comprising text, images, audio or video) to other computers on the network (E-mail), multimedia editing or game play, usually used to run software not written by the user. Unlike minicomputers, a personal computer is often owned by the person using it, representing a low cost of purchase and simplicity of operation. The user of a modern personal computer may have significant knowledge of the operating environment and application programs, but is not necessarily interested in programming nor even able to write programs for the computer.
In modern usage PC nearly always refers to an IBM PC compatible and the term may even be used for machines that are in no way personal computers but still use the basic architecture of the IBM PC.
In modern usage PC nearly always refers to an IBM PC compatible and the term may even be used for machines that are in no way personal computers but still use the basic architecture of the IBM PC.
Wednesday, March 21, 2007
Light Pollution
In urban areas light pollution can hide the stars and get in the way with astronomy. In settings near astronomical telescopes and observatories, low pressure sodium lamps may be used. These lamps are beneficial over other lamps such as mercury and halogen lamps because low pressure sodium lamps emit lower intensity, monochromatic light. Observatories can filter the sodium wavelength out of their observations and almost eliminate the interference from nearby urban lighting.The light pollution also disrupts the natural increasing cycle of plants.
Friday, March 16, 2007
Bournemouth
Bournemouth is a seaside resort in the county of Dorset on the south coast of England. It is situated about 107 miles southwest of London, at latitude 50.43N and longitude 1.54W. The town overlooks Poole Bay.
It was initially part of Hampshire but was ceded to Dorset in a 1974 local government reform. proof of this can be found at a roundabout at the end of the Wessex Way called "County gates" where the gate marking the divide between Hampshire and Dorset once stood, and which now marks the border between Poole and Bournemouth. On April 1, 1997 Bournemouth became an independent unitary authority.
Bournemouth is one of the most popular tourist destinations on the English south coast, as of its fine long beach, the wide range of accommodation and entertainment, the mild climate, and easy access to the New Forest, Jurassic Coast, Devon, and the Dorset and Hampshire countryside. This section of the English coast enjoys some of the warmest, driest, and sunniest weather in Britain.
It was initially part of Hampshire but was ceded to Dorset in a 1974 local government reform. proof of this can be found at a roundabout at the end of the Wessex Way called "County gates" where the gate marking the divide between Hampshire and Dorset once stood, and which now marks the border between Poole and Bournemouth. On April 1, 1997 Bournemouth became an independent unitary authority.
Bournemouth is one of the most popular tourist destinations on the English south coast, as of its fine long beach, the wide range of accommodation and entertainment, the mild climate, and easy access to the New Forest, Jurassic Coast, Devon, and the Dorset and Hampshire countryside. This section of the English coast enjoys some of the warmest, driest, and sunniest weather in Britain.
Sunday, March 11, 2007
Ice travel
Ice can also be an obstacle; for harbors near the poles, being ice-free is an significant advantage, ideally all-year round. Examples are Murmansk (Russia), Petsamo (Russia, formerly Finland) and Vardø (Norway). Harbors that are not ice-free are opened up using icebreakers.
Ice forming on roads is a unsafe winter hazard. Black ice is very difficult to see because it lacks the predictable glossy surface. Whenever there is freezing rain or snow that occurs at a temperature near the melting point, it is common for ice to build up on the windows of vehicles. Driving safely requires the removal of the ice build-up. Ice scrapers are tools designed to break the ice free and clear the windows, while removing the ice can be a long and labor-intensive process.
Far enough below the freezing point, a thin layer of ice crystals can form on the inside surface of windows. This frequently happens when a vehicle has been left alone after being driven for a while, but can happen while driving if the outside temperature is low enough. Moisture from the driver's breath is the source of water for the crystals. It is troublesome to take away this form of ice, so people often open their windows somewhat when the vehicle is parked in order to let the moisture dissipate, and it is now common for cars to have rear-window defrosters to combat the problem. A similar problem can happen in homes, which is one reason why many colder regions require double-pane windows for insulation.
When the outdoor temperature stays below freezing for comprehensive periods, very thick layers of ice can form on lakes and other bodies of water (although places with flowing water require much colder temperatures). The ice can become thick enough to drive onto with automobiles and trucks. Doing this safely requires a thickness of at least 30 centimeters (one foot).
Ice forming on roads is a unsafe winter hazard. Black ice is very difficult to see because it lacks the predictable glossy surface. Whenever there is freezing rain or snow that occurs at a temperature near the melting point, it is common for ice to build up on the windows of vehicles. Driving safely requires the removal of the ice build-up. Ice scrapers are tools designed to break the ice free and clear the windows, while removing the ice can be a long and labor-intensive process.
Far enough below the freezing point, a thin layer of ice crystals can form on the inside surface of windows. This frequently happens when a vehicle has been left alone after being driven for a while, but can happen while driving if the outside temperature is low enough. Moisture from the driver's breath is the source of water for the crystals. It is troublesome to take away this form of ice, so people often open their windows somewhat when the vehicle is parked in order to let the moisture dissipate, and it is now common for cars to have rear-window defrosters to combat the problem. A similar problem can happen in homes, which is one reason why many colder regions require double-pane windows for insulation.
When the outdoor temperature stays below freezing for comprehensive periods, very thick layers of ice can form on lakes and other bodies of water (although places with flowing water require much colder temperatures). The ice can become thick enough to drive onto with automobiles and trucks. Doing this safely requires a thickness of at least 30 centimeters (one foot).
Tuesday, March 06, 2007
Piano
A piano or pianoforte is a musical instrument classified as a keyboard, percussion, or string instrument, depending on the system of categorization used. The piano produces sound by striking steel strings with felt hammers that at once rebound allowing the string to continue vibrating at its resonant frequency. These vibrations are transmitted through the bridges to the soundboard, which amplifies them.
The piano is generally used in western music for solo performance, chamber music, and accompaniment. It is also very popular as an aid to composing and rehearsal. Even though not portable and often expensive, the piano's versatility and ubiquity has made it among the most familiar of musical instruments.
The word piano is a shortened form of the word pianoforte, which is seldom used except in formal language and resultant from the original Italian name for the instrument, gravicèmbalo col piano e forte (literally harpsichord with soft and loud). This refers to the capability of the piano to produce notes at different volumes depending on the amount of force used to press the keys.
The piano is generally used in western music for solo performance, chamber music, and accompaniment. It is also very popular as an aid to composing and rehearsal. Even though not portable and often expensive, the piano's versatility and ubiquity has made it among the most familiar of musical instruments.
The word piano is a shortened form of the word pianoforte, which is seldom used except in formal language and resultant from the original Italian name for the instrument, gravicèmbalo col piano e forte (literally harpsichord with soft and loud). This refers to the capability of the piano to produce notes at different volumes depending on the amount of force used to press the keys.
Thursday, March 01, 2007
Coconut water
Coconut water is the liquid endosperm inside young coconuts. As the coconut matures this liquid mostly becomes absorbed into the flesh found in grown-up coconuts. Coconut water has long been a popular drink in the tropics. It is logically fat-free and low in food energy (16.7 calories or 70 kJ per 100 g). Due to its sterility, pH, mineral, and sugar content, coconut water had been effectively used as liquid in intravenous therapy in crisis situations.
Coconuts for drinking are packaged and sold in many places. These are typically Thai coconuts whose outer green husk has been removed, and the rest wrapped in plastic. Coconut water can also be found in regular cans or tetra paks, and is also marketed as a sports drink because of its high potassium and mineral content which helps the body recover from rigorous exercise.
It can also be used as intravenous fluid resuscitation of patients with dehydration or hypovolemia, because it is isotonic and sterile.
Coconuts for drinking are packaged and sold in many places. These are typically Thai coconuts whose outer green husk has been removed, and the rest wrapped in plastic. Coconut water can also be found in regular cans or tetra paks, and is also marketed as a sports drink because of its high potassium and mineral content which helps the body recover from rigorous exercise.
It can also be used as intravenous fluid resuscitation of patients with dehydration or hypovolemia, because it is isotonic and sterile.
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