enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Planck's law - Wikipedia

    en.wikipedia.org/wiki/Planck's_law

    In 1905, "Einstein believed that Planck's theory could not be made to agree with the idea of light quanta, a mistake he corrected in 1906." [133] Contrary to Planck's beliefs of the time, Einstein proposed a model and formula whereby light was emitted, absorbed, and propagated in free space in energy quanta localized in points of space. [132]

  3. Bessel function - Wikipedia

    en.wikipedia.org/wiki/Bessel_function

    Bessel function. Bessel functions describe the radial part of vibrations of a circular membrane. Bessel functions, first defined by the mathematician Daniel Bernoulli and then generalized by Friedrich Bessel, are canonical solutions y(x) of Bessel's differential equation for an arbitrary complex number , which represents the order of the Bessel ...

  4. Pythagorean theorem - Wikipedia

    en.wikipedia.org/wiki/Pythagorean_theorem

    In mathematics, the Pythagorean theorem or Pythagoras' theorem is a fundamental relation in Euclidean geometry between the three sides of a right triangle. It states that the area of the square whose side is the hypotenuse (the side opposite the right angle) is equal to the sum of the areas of the squares on the other two sides.

  5. Drake equation - Wikipedia

    en.wikipedia.org/wiki/Drake_equation

    The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way Galaxy. [ 1 ] [ 2 ] [ 3 ] The equation was formulated in 1961 by Frank Drake , not for purposes of quantifying the number of civilizations, but as a way to stimulate scientific dialogue at the first ...

  6. Maxwell's equations - Wikipedia

    en.wikipedia.org/wiki/Maxwell's_equations

    Maxwell's equations, or Maxwell–Heaviside equations, are a set of coupled partial differential equations that, together with the Lorentz force law, form the foundation of classical electromagnetism, classical optics, electric and magnetic circuits. The equations provide a mathematical model for electric, optical, and radio technologies, such ...

  7. Relativistic Lagrangian mechanics - Wikipedia

    en.wikipedia.org/wiki/Relativistic_Lagrangian...

    The relativistic Lagrangian can be derived in relativistic mechanics to be of the form: Although, unlike non-relativistic mechanics, the relativistic Lagrangian is not expressed as difference of kinetic energy with potential energy, the relativistic Hamiltonian corresponds to total energy in a similar manner but without including rest energy.

  8. Hamilton–Jacobi equation - Wikipedia

    en.wikipedia.org/wiki/Hamilton–Jacobi_equation

    The Hamilton–Jacobi equation is a first-order, non-linear partial differential equation. for a system of particles at coordinates ⁠ ⁠. The function is the system's Hamiltonian giving the system's energy. The solution of the equation is the action functional, ⁠ ⁠, [4] called Hamilton's principal function in older textbooks.

  9. Lagrangian mechanics - Wikipedia

    en.wikipedia.org/wiki/Lagrangian_mechanics

    Lagrangian mechanics describes a mechanical system as a pair (M, L) consisting of a configuration space M and a smooth function within that space called a Lagrangian. For many systems, L = T − V, where T and V are the kinetic and potential energy of the system, respectively. [3]