Parabolic reflector

A parabolic reflector (also known as a parabolic dish or a parabolic mirror) is a reflective device formed in the shape of a paraboloid of revolution. Parabolic reflectors can either collect or distribute energy such as light, sound, or radio waves.

Related Topics:
Reflective - Paraboloid of revolution - Energy - Light - Sound - Radio wave

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The parabolic reflector functions due to the geometric properties of the paraboloid shape: if the angle of incidence to the inner surface of the collector equals the angle of reflection, then any incoming ray that is parallel to the axis of the dish will be reflected to a central point, or "focus". Because many types of energy can be reflected in this way, parabolic reflectors can be used to collect and concentrate energy entering the reflector at a particular angle. Similarly, energy radiating from the "focus" to the dish can be transmitted outward in a beam that is parallel to the axis of the dish.

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Isaac Newton introduced parabolic mirrors into practical astronomy when he invented the reflecting telescope. The most common applications of the parabolic reflector are in satellite dishes, telescopes (including radio telescopes), parabolic microphones, and many lighting devices such as spotlights, car headlights, and LED housings.

Related Topics:
Isaac Newton - Astronomy - Reflecting telescope - Satellite dish - Telescope - Parabolic microphone - Lighting - Spotlight - Car headlights

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Parabolic reflectors suffer from an aberration called coma. This is only of interest in telescopes because other applications don't require sharp resolution off the axis of the parabola.

Related Topics:
Aberration - Coma

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The Olympic Flame is lit using a parabolic reflector concentrating sunlight.

Related Topics:
Olympic Flame - Sunlight

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A toy consisting of two parabolic mirrors that are put together like a wok pan and a lid with a hole in it, gives the optical illusion that something is on the lid, but actually it is at the bottom of the pan below.

Related Topics:
Wok pan - Optical illusion

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