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  2. Isaac Newton - Wikipedia

    en.wikipedia.org/wiki/Isaac_Newton

    During this period he investigated the refraction of light, demonstrating that the multicoloured image produced by a prism, which he named a spectrum, could be recomposed into white light by a lens and a second prism. [63] Modern scholarship has revealed that Newton's analysis and resynthesis of white light owes a debt to corpuscular alchemy. [64]

  3. Dirac equation - Wikipedia

    en.wikipedia.org/wiki/Dirac_equation

    Quantum mechanics. In particle physics, the Dirac equation is a relativistic wave equation derived by British physicist Paul Dirac in 1928. In its free form, or including electromagnetic interactions, it describes all spin-1/2 massive particles, called "Dirac particles", such as electrons and quarks for which parity is a symmetry. It is ...

  4. Discrete Fourier transform - Wikipedia

    en.wikipedia.org/wiki/Discrete_Fourier_transform

    In mathematics, the discrete Fourier transform (DFT) converts a finite sequence of equally-spaced samples of a function into a same-length sequence of equally-spaced samples of the discrete-time Fourier transform (DTFT), which is a complex-valued function of frequency. The interval at which the DTFT is sampled is the reciprocal of the duration ...

  5. 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 ...

  6. Mass–energy equivalence - Wikipedia

    en.wikipedia.org/wiki/Mass–energy_equivalence

    In physics, mass–energy equivalence is the relationship between mass and energy in a system's rest frame, where the two quantities differ only by a multiplicative constant and the units of measurement. [1][2] The principle is described by the physicist Albert Einstein 's formula: . [3] In a reference frame where the system is moving, its ...

  7. Platonic solid - Wikipedia

    en.wikipedia.org/wiki/Platonic_solid

    This follows from the spherical excess formula for a spherical polygon and the fact that the vertex figure of the polyhedron {p,q} is a regular q-gon. The solid angle of a face subtended from the center of a platonic solid is equal to the solid angle of a full sphere (4 π steradians) divided by the number of faces. This is equal to the angular ...

  8. Laplace's method - Wikipedia

    en.wikipedia.org/wiki/Laplace's_method

    Laplace's method. In mathematics, Laplace's method, named after Pierre-Simon Laplace, is a technique used to approximate integrals of the form. where is a twice- differentiable function, is a large number, and the endpoints and could be infinite. This technique was originally presented in the book by Laplace (1774).

  9. Kepler's laws of planetary motion - Wikipedia

    en.wikipedia.org/wiki/Kepler's_laws_of_planetary...

    Kepler used his two first laws to compute the position of a planet as a function of time. His method involves the solution of a transcendental equation called Kepler's equation. The procedure for calculating the heliocentric polar coordinates (r,θ) of a planet as a function of the time t since perihelion, is the following five steps: