Night VisionWritten by Jonny McPhil
Night Vision is an optical device consisting of high-quality image intensifier tubes and optics that amplify existing light. The Night Vision gives you ability to see in conditions that are too dark for a naked eye. Every Night Vision product has an Infrared Illuminator. The Infrared Illuminator provides a light source for system to amplify images. It can give you enhanced images in very low light conditions, such as caves, where no ambient light is available for amplification of objects inside.
The working principle of a Night Vision is simple as well as interesting. In very dark conditions, available light, like starlight, moonlight or infra-red light is gathered by front Objective Lens of Night Vision. The objective lens then transmits it through a set of optical lenses to Electronic Intensifier Tube (EIT.). The high levels of energy that is produced by device's intricate power supply rap out electrons from Photocathode Screen, located on front of Electronic Intensifier Tube.
The same energy from EIT generates a highly static field, pushing electrons to Phosphorescent Screen, which is a very sensitive layer at back of EIT. These electrons strike Phosphorescent Screen with immense speed and allow it to illuminate. This whole procedure produces an image, which is then magnified by Ocular Lens located at back of Night Vision. By looking through ocular lens of Night Vision, you will see image as you see in a normal optical device.
Wikipedia Vs Britanica Encyclopaedia madnessWritten by Yasir Ikram
When information highway evolves into a planet of shared knowledge, there has to be a method to madness. Toward this end, wikis are revolutionising way we handle information.
WIKIPEDIA: Wikipedia is a web-based, free content encyclopardia that is a collaborative effort involving several volunteers. wikipedia currently contains 1.5 million articles, more than 570,000 if which are in its english language edition, while german edition boasts 200,000 articles. The Japanese and French editions house approximately 100,000 articles each. These articles are constantly edited and added to by volunteers primarily following a "neutral point of view" guideline.
BRITANNICA: By comparison, Encyclopaedia Britannica has only 80,000 articles hence enormity of wikipedia alone is a clear measure of its success. wikipedia has more than 512 million word as of May 2005. Even taking every single revision of wikipedia into account, its entire database stands at only 35 gigabytes - they don`t even make hard drives that small anymore.