Welcome to Citizendium

From Citizendium
Jump to navigation Jump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
New Blog Post
Why save Citizendium? My reason number 1.
See the Technical Forum for news of new tools being made available.

Help Write Articles about our World

Welcome to Citizendium, a wiki for providing free knowledge where authors use their real names. We write the kinds of encyclopedia-style articles that Wikipedia can't write. We regard information as a public good and welcome anyone who wants to share their knowledge on virtually any subject. Our online community prides itself on being congenial and supportive.

Our goals have changed over the years. Please read more about who we are.

See Recent Changes—an overview of articles we are writing now.

Please help today!
Please make your donations here.
Donations go to keep our servers running. See our financial report.

Become a member--it's free!

Agriculture Earth Sciences Journalism Physics
Anthropology Economics Law Politics
Archaeology Education Library & Info. Sci. Psychology
Architecture Engineering Linguistics Religion
Astronomy Food Science Literature Robotics
Biology Games Mathematics Sociology
Business Geography Media Sports
Chemistry Health Sciences Military Theater
Classics History Music Topic Informant
Computers Hobbies Philosophy Visual Arts

Our help system and forum
Questions and answers to help you find the information you need

Article counts

Citable Articles (148)
Developed Articles (1,178)
Developing Articles (8,840)
Stubs (7,526)
(17,819 total articles)

That which we know is a little thing; that which we do not know is immense.
Pierre-Simon de Laplace (1749–1827), French physicist and mathematician, systematizer and elaborator of probability theory
       —add a quotation about knowledge or writing

Featured Article: Scientific method

CC Image
Statue of David Hume. "Man is a reasonable being; and as such, receives from science his proper food and nourishment: But so narrow are the bounds of human understanding, that little satisfaction can be hoped for in this particular..." Hume recognised clearly the difficulties in gaining a general understanding merely by accumulating observations.

Scientists use a scientific method to investigate phenomena and acquire knowledge. They base the method on verifiable observation — i.e., on replicable empirical evidence rather than on pure logic or supposition — and on the principles of reasoning.[1] [2] Scientists propose explanations — called hypotheses — for their observed phenomena, and perform experiments to determine whether the results accord with (support) the hypotheses or falsify them. They also formulate theories that encompass whole domains of inquiry, and which bind supported hypotheses together into logically coherent wholes. They refer to theories sometimes as ‘models’, which often have a mathematical or computational basis.[3] [4]


  1. Isaac Newton (1643-1727) The Rules of Reasoning in Philosophy Excerpts in: The Mathematical Principles of Natural Philosophy. Source: Modern History Sourcebook
  2. Full-Text: Newton's Principia: The Mathematical Principles of Natural Philosophy (c1846), including BOOK III. RULES OF REASONING IN PHILOSOPHY
  3. Leng G, MacGregor DJ. (2008) Mathematical Modelling in Neuroendocrinology. Journal of Neuroendocrinology: From Molecular to Translational Neurobiology 20:713-718.
    • Excerpt: Our science is not only about facts, but also about explanations; rational accounts of phenomena, embedded in a framework of theory, which include a wide range of observations and which are predictive of behaviour in circumstances as yet untested. We all seek to explain the world of observations using a set of logically interacting components, and we all simplify by recognising that some observations are important while others can be reasonably neglected. Formulating such explanations mathematically is a natural ambition, because this ensures their logical consistency, and makes them open to structured analysis; it is a stringent test of their intellectual coherence.
  4. Citizendium Collaborators. (2009) Biology’s Next Microscope: Mathematics. Citizendium Free Online Encyclopedia.
    • Excerpt: Mathematics broadly interpreted is a more general microscope. It can reveal otherwise invisible worlds in all kinds of data, not only optical….Charles Darwin was right when he wrote that people with an understanding “of the great leading principles of mathematics... seem to have an extra sense”….Today’s biologists increasingly recognize that appropriate mathematics can help interpret any kind of data. In this sense, mathematics is biology’s next microscope, only better.