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A curved mirror is a mirror with a curved reflecting surface. The surface may be either convex (bulging outward) or concave (recessed inward). Most curved mirrors have surfaces that are shaped like part of a sphere, but other shapes are sometimes used in optical devices. The most common non-spherical type are parabolic reflectors, found in ...
Convex optimization is a subfield of mathematical optimization that studies the problem of minimizing convex functions over convex sets (or, equivalently, maximizing concave functions over convex sets). Many classes of convex optimization problems admit polynomial-time algorithms, [1] whereas mathematical optimization is in general NP-hard. [2 ...
The Cassegrain reflector is a combination of a primary concave mirror and a secondary convex mirror, often used in optical telescopes and radio antennas, the main characteristic being that the optical path folds back onto itself, relative to the optical system's primary mirror entrance aperture. This design puts the focal point at a convenient ...
We are also given differentiable convex function :, -strongly convex with respect to the given norm. This is called the distance-generating function , and its gradient ∇ h : R n → R n {\displaystyle \nabla h\colon \mathbb {R} ^{n}\to \mathbb {R} ^{n}} is known as the mirror map .
Plane mirror. A plane mirror showing the virtual image of an urn nearby. A diagram of an object in two plane mirrors that formed an angle bigger than 90 degrees, causing the object to have three reflections. A plane mirror is a mirror with a flat (planar) reflective surface. [1][2] For light rays striking a plane mirror, the angle of reflection ...
A convex secondary mirror is placed just to the side of the light entering the telescope, and positioned afocally so as to send parallel light on to the tertiary. The concave tertiary mirror is positioned exactly twice as far to the side of the entering beam as was the convex secondary, and its own radius of curvature distant from the secondary.
The rings in the centre extend the confinement volume horizontally, but are not strictly needed and are not found on many mirror machines. A magnetic mirror, also known as a magnetic trap or sometimes as a pyrotron, is a type of magnetic confinement fusion device used in fusion power to trap high temperature plasma using magnetic fields.
Foucault test setup to measure a mirror. The Foucault knife-edge test is an optical test to accurately measure the shape of concave curved mirrors. It is commonly used by amateur telescope makers for figuring primary mirrors in reflecting telescopes. It uses a relatively simple, inexpensive apparatus compared to other testing techniques.