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 and other sites 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. Please read about who we are in 2022.
See Recent Changes—an overview of articles we are writing now.
Citable Articles (153)
Developed Articles (1,175)
(17,519 total articles)
We do but learn today what our better advanced judgements will unteach tomorrow.
— Sir Thomas Browne
—add a quotation about knowledge or writing
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.  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.