Welcome to Citizendium

Natural Sciences           Social Sciences           Humanities     Arts           Applied Arts and Sciences           Recreation

A new wiki encyclopedia project—and more! We aim at reliability and quality, not just quantity. We welcome collaboration with everyone who has knowledge, broad or narrow, about any of the world's innumerable subjects. We write under our real names—and are both collegial and congenial. We now have [[:Category:CZ Live|Template:Articles number+ articles]] and are gathering speed. Eduzendium participants write for academic credit. Write for the Citizendium—knowledge is fun! Sign up—we need both authors and editors (you might be both!) Then, get a quick start. Remember, we are an open, young project—it's easy to get involved! Wikipedians are very welcome! Learn about us Why Citizendium? For readers: About | FAQ For contributors: Authors | Editors | How to collaborate For the press Important new community pages WatchKnow will be a free, non-profit, K-12 educational video contest, currently under planning and development. Myths and Facts: Citizendium may be different from what you think! We are organizing Workgroup Weeks—our biggest initiative yet. Citizens, get involved, and watch our numbers multiply! Cleanup—helps to develop, keep and maintain a coherent structure for entries in Citizendium. Support us Our mission is educational, non-profit, global, and free. Shop at our Amazon.com and Barnes & Noble links and we'll get donations at no cost to you. Link to us so search engines can better find us.   (CC) Photo: Tanya Puntti Each sentence you add is another drop in an expanding sea of words.

Some of our finest [ about ] Approved Articles Developed Articles (over 900) "The ink of the learned is equal in merit to the blood of the martyrs." —Father Kristoforos, Birds Without Wings, by Louis de Bernières (b. 1954) Article of the Week [ about ] (CC) Photo: Daniel Ullrich Coal-fired power plant in Voerde, Germany A conventional coal-fired power plant produces electricity by burning coal in a steam generator that heats water to produce high pressure and high temperature steam. The steam flows through a series of steam turbines which spin an electrical generator to produce electricity. The exhaust steam from the turbines is cooled, condensed back into water, and returned to the steam generator to start the process over. Conventional coal-fired power plants are highly complex and custom designed on a large scale for continuous operation 24 hours per day and 365 days per year. Such plants provide most of the electrical energy used in many countries. Most plants built in the 1980s and early 1990s have a power of around 500 MW (500•106 watt), while many of the modern plants have a power of around 1000 MW. Also the efficiencies (ratio of electrical energy produced to energy released by the coal burned) of conventional coal-fired plants increased from under 35% to close to 45%. Because of the second law of thermodynamics there is a fixed physical limit on the efficiency. By Carnot's law the limit is proportional to the temperature difference of the steam and the cooling water, with the consequence that the efficiency of a plant cannot surpass 50% by much.[more...] New Draft of the Week [ about ] The Jass–Belote card games are a family of trick-taking card games in which the Jack ("jass") and Nine of the trump suit are the highest-ranking trumps, and the Tens and Aces of all suits are the next most valuable cards. Games in this family are typically played by 2 or 4 players with the 32 French-suited cards of a piquet pack. Variants of the basic 2-handed game – known under various names including Klaberjas, Clob and Bela – are played worldwide, especially in Jewish communities. 4-handed Belote with its numerous variants is the French national card game but has spread as far away as Cyprus and Saudi-Arabia. Other notable members of the family include the Swiss and Dutch national card games (Swiss Jass and Dutch Klaverjas). Twenty-Nine, a popular game in South Asia, is a descendent of these games sharing many of their characteristics. [more...]