Search results
Results from the WOW.Com Content Network
Robert Fludd's 1618 "water screw" perpetual motion machine from a 1660 wood engraving.It is widely credited as the first attempt to describe such a device. [note 1] [1] Something for Nothing (1940), a short film featuring Rube Goldberg illustrating the U.S. Patent Office's policy regarding perpetual motion machines (and the power efficiency of gasoline)
An engraving of Robert Fludd's 1618 "water screw" perpetual motion machine.. The history of perpetual motion machines dates at least back to the Middle Ages.For millennia, it was not clear whether perpetual motion devices were possible or not, but modern theories of thermodynamics have shown that they are impossible.
The following table lists many common symbols, together with their name, how they should be read out loud, and the related field of mathematics. Additionally, the subsequent columns contains an informal explanation, a short example, the Unicode location, the name for use in HTML documents, [1] and the LaTeX symbol.
Depending on authors, the term "maps" or the term "functions" may be reserved for specific kinds of functions or morphisms (e.g., function as an analytic term and map as a general term). mathematics See mathematics. multivalued A "multivalued function” from a set A to a set B is a function from A to the subsets of B.
In a figure / ground ambigram, letters fit together so the negative space around and between one word spells another word. [42] In Gestalt psychology, figure–ground perception is known as identifying a figure from the background. For example, black words on a printed paper are seen as the "figure", and the white sheet as the "background".
In mathematics and physics, the term generator or generating set may refer to any of a number of related concepts. The underlying concept in each case is that of a smaller set of objects, together with a set of operations that can be applied to it, that result in the creation of a larger collection of objects, called the generated set .
A term can be visualized as a tree of symbols, the set of admitted symbols being fixed by a given signature. As a formalism, term rewriting systems have the full power of Turing machines, that is, every computable function can be defined by a term rewriting system. [13] Some programming languages are based on term rewriting.
Relations saying that one relation is a positive power of R times another *91.01, *91.02 Pot (Short for the Latin word "potentia" meaning power.) The positive powers of a relation *91.03 Potid ("Pot" for "potentia" + "id" for "identity".) The positive or zero powers of a relation *91.04 R po: The union of the positive power of R *91.05 B