Mirror
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A mirror, also known as a looking glass, is an object that reflects an image. Light that bounces off a mirror forms an image of whatever is in front of it, which is then focused through the lens of th
A mirror reflecting the image of a vase
A first-surface mirror coated with aluminium and enhanced with dielectric coatings. The angle of the incident light (represented by both the light in the mirror and the shadow behind it) exactly matches the angle of reflection (the reflected light shining on the table).
4.5-metre (15 ft)-tall acoustic mirror near Kilnsea Grange, East Yorkshire, UK, from World War I. The mirror magnified the sound of approaching enemy Zeppelins for a microphone placed at the focal point. Sound waves are much longer than light waves, thus the object produces diffuse reflections in the visual spectrum.
Roman fresco of a woman fixing her hair using a mirror, from Stabiae, Italy, 1st century AD
Speculum metal
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Speculum metal is a mixture of around two-thirds copper and one-third tin, making a white brittle alloy that can be polished to make a highly reflective surface. It was used historically to make diffe
Mirror
…norm through to Greco-Roman Antiquity and throughout the Middle Ages in Europe. During the Roman Empire silver mirrors were in wide use by servants. Speculum metal is a highly reflective alloy of copper and tin that was used for mirrors until a couple of centuries ago. Up until the mid-19th century, many astronomical…
The speculum metal mirror from William Herschel's 1.2-meter (49.5-inch) diameter "40-foot telescope" at the Science Museum in London
Modern replica of Herschel's 6.2"-aperture Newtonian telescope which had a speculum metal main mirror
Leviathan telescope. Telescopes with speculum metal mirrors were a large breakthrough in aperture, but their drawbacks fueled competition from refractors
The metal mirror of the Leviathan, the largest telescope mirror until the 100-inch Hooker telescope of 1917 (a metal-on-glass mirror)