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  2. Free-air gravity anomaly - Wikipedia

    en.wikipedia.org/wiki/Free-air_gravity_anomaly

    Calculation. The free-air gravity anomaly is given by the equation: = (+) Here, is observed gravity, is the free-air correction, and is theoretical gravity.

  3. Prism correction - Wikipedia

    en.wikipedia.org/wiki/Prism_correction

    Prentice's rule, named so after the optician Charles F. Prentice, is a formula used to determine the amount of induced prism in a lens: = where: P is the amount of prism correction (in prism dioptres) c is decentration (the distance between the pupil centre and the lens's optical centre, in millimetres)

  4. Anisometropia - Wikipedia

    en.wikipedia.org/wiki/Anisometropia

    Amblyopia. Anisometropia is a condition in which a person's eyes have substantially differing refractive power. [1] Generally, a difference in power of one diopter (1D) is the threshold for diagnosis of the condition . [2] [3] Patients may have up to 3D of anisometropia before the condition becomes clinically significant due to headache, eye ...

  5. Minimum deviation - Wikipedia

    en.wikipedia.org/wiki/Minimum_deviation

    Using a similar approach with the Snell's law and the prism formula for an in general thin-prism ends up in the very same result for the deviation angle. Because i , e and r are small, n ≈ i r 1 , n ≈ e r 2 {\displaystyle n\approx {\frac {i}{r_{1}}},n\approx {\frac {e}{r_{2}}}}

  6. Scherrer equation - Wikipedia

    en.wikipedia.org/wiki/Scherrer_Equation

    The Scherrer equation, in X-ray diffraction and crystallography, is a formula that relates the size of sub-micrometre crystallites in a solid to the broadening of a peak in a diffraction pattern. It is often referred to, incorrectly, as a formula for particle size measurement or analysis.

  7. Eötvös effect - Wikipedia

    en.wikipedia.org/wiki/Eötvös_effect

    The force of gravity and the normal force. The resultant force acts as the required centripetal force. The mathematical derivation for the Eötvös effect for motion along the Equator explains the factor 2 in the first term of the Eötvös correction formula. What remains to be explained is the cosine factor.

  8. Brewster's angle - Wikipedia

    en.wikipedia.org/wiki/Brewster's_angle

    one can calculate the incident angle θ 1 = θ B at which no light is reflected: n 1 sin ⁡ θ B = n 2 sin ⁡ ( 90 ∘ − θ B ) = n 2 cos ⁡ θ B . {\displaystyle n_{1}\sin \theta _{\mathrm {B} }=n_{2}\sin(90^{\circ }-\theta _{\mathrm {B} })=n_{2}\cos \theta _{\mathrm {B} }.}

  9. Gravity anomaly - Wikipedia

    en.wikipedia.org/wiki/Gravity_anomaly

    The normal gravity accounts for the bulk gravitation of the entire Earth, corrected for its idealized shape and rotation. It is given by the formula: where = 9.780 327 m⋅s−2; = 5.302 44 × 10−3; and = −5.8 × 10−6. This is accurate to 0.1 mgal at any latitude .

  10. Spherical aberration - Wikipedia

    en.wikipedia.org/wiki/Spherical_aberration

    Spherical aberration of collimated light incident on a concave spherical mirror. In optics, spherical aberration ( SA) is a type of aberration found in optical systems that have elements with spherical surfaces. This phenomenon commonly affects lenses and curved mirrors, as these components are often shaped in a spherical manner for ease of ...

  11. Perturbation theory (quantum mechanics) - Wikipedia

    en.wikipedia.org/wiki/Perturbation_theory...

    In quantum mechanics, perturbation theory is a set of approximation schemes directly related to mathematical perturbation for describing a complicated quantum system in terms of a simpler one. The idea is to start with a simple system for which a mathematical solution is known, and add an additional "perturbing" Hamiltonian representing a weak ...