enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Entropy and life - Wikipedia

    en.wikipedia.org/wiki/Entropy_and_life

    Research concerning the relationship between the thermodynamic quantity entropy and both the origin and evolution of life began around the turn of the 20th century. In 1910 American historian Henry Adams printed and distributed to university libraries and history professors the small volume A Letter to American Teachers of History proposing a theory of history based on the second law of ...

  3. Decidability of first-order theories of the real numbers

    en.wikipedia.org/wiki/Decidability_of_first...

    In mathematical logic, a first-order language of the real numbers is the set of all well-formed sentences of first-order logic that involve universal and existential quantifiers and logical combinations of equalities and inequalities of expressions over real variables. The corresponding first-order theory is the set of sentences that are ...

  4. Second-order logic - Wikipedia

    en.wikipedia.org/wiki/Second-order_logic

    For example, if the domain is the set of all real numbers, one can assert in first-order logic the existence of an additive inverse of each real number by writing ∀x ∃y (x + y = 0) but one needs second-order logic to assert the least-upper-bound property for sets of real numbers, which states that every bounded, nonempty set of real numbers ...

  5. Phase transition - Wikipedia

    en.wikipedia.org/wiki/Phase_transition

    First-order phase transitions exhibit a discontinuity in the first derivative of the free energy with respect to some thermodynamic variable. [6] The various solid/liquid/gas transitions are classified as first-order transitions because they involve a discontinuous change in density, which is the (inverse of the) first derivative of the free ...

  6. Entropy (order and disorder) - Wikipedia

    en.wikipedia.org/wiki/Entropy_(order_and_disorder)

    An example of an order parameter for crystallization is "bond orientational order" describing the development of preferred directions (the crystallographic axes) in space. For many systems, phases with more structural (e.g. crystalline) order exhibit less entropy than fluid phases under the same thermodynamic conditions.

  7. List of first-order theories - Wikipedia

    en.wikipedia.org/wiki/List_of_first-order_theories

    This is not a first-order axiomatization as one of Hilbert's axioms is a second order completeness axiom. Tarski's axioms are a first-order axiomatization of Euclidean geometry. Tarski showed this axiom system is complete and decidable by relating it to the complete and decidable theory of real closed fields.

  8. Entropy as an arrow of time - Wikipedia

    en.wikipedia.org/wiki/Entropy_as_an_arrow_of_time

    This is closely related to the second law of thermodynamics: For example, in a finite system interacting with finite heat reservoirs, entropy is equivalent to system-reservoir correlations, and thus both increase together. [5] Take for example (experiment A) a closed box that is, at the beginning, half-filled with ideal gas.

  9. Community psychology - Wikipedia

    en.wikipedia.org/wiki/Community_psychology

    first-order change: positively changing the individuals in a setting to attempt to fix a problem; second-order change: Attending to systems and structures involved with the problem to adjust the person–environment fit; As an example of how these methods differ, consider homelessness.