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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)
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 ...
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.
Example. Consider a pair of spectacles to correct for myopia with a prescription of −1.00 m −1 in one eye and −4.00 m −1 in the other. Suppose that for both eyes the other parameters are identical, namely t = 1 mm = 0.001 m, n = 1.6, P = 5 m −1, and h = 15 mm = 0.015 m.
The De Broglie relations give the relation between them: ϕ = h f 0 {\displaystyle \phi =hf_ {0}\,\!} Photon momentum. p = momentum of photon (kg m s −1) f = frequency of photon (Hz = s −1) λ = wavelength of photon (m) The De Broglie relations give: p = h f / c = h / λ {\displaystyle p=hf/c=h/\lambda \,\!}
Esophoria is an eye condition involving inward deviation of the eye, usually due to extra-ocular muscle imbalance. It is a type of heterophoria. Cause. Causes include: Refractive errors; Divergence insufficiency; Convergence excess; this can be due to nerve, muscle, congenital or mechanical anomalies.
The formula for vertex correction is = (), where F c is the power corrected for vertex distance, F is the original lens power, and x is the change in vertex distance in meters.
The free air correction is calculated from Newton's Law, as a rate of change of gravity with distance: g = G M R 2 d g d R = − 2 G M R 3 = − 2 g R {\displaystyle {\begin{aligned}g&={\frac {GM}{R^{2}}}\\{\frac {dg}{dR}}&=-{\frac {2GM}{R^{3}}}=-{\frac {2g}{R}}\end{aligned}}}
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 ...
The Klein–Gordon equation and the Dirac equation are two such equations. The Klein–Gordon equation, The Klein–Gordon equation, − 1 c 2 ∂ 2 ∂ t 2 ψ + ∇ 2 ψ = m 2 c 2 ℏ 2 ψ , {\displaystyle -{\frac {1}{c^{2}}}{\frac {\partial ^{2}}{\partial t^{2}}}\psi + abla ^{2}\psi ={\frac {m^{2}c^{2}}{\hbar ^{2}}}\psi ,}