Question

The Science of Curved Mirror Optics

When did this topic emerge? How was the concept built and developed? Notable scientists involved in developing the topic; Are they alive still? Are they credited with any other discoveries?

Answer 1

In his Optics Greek mathematician Euclid observed that "things seen under a greater angle appear greater, and those under a lesser angle less, while those under equal angles appear equal". In the 36 propositions that follow, Euclid relates the apparent size of an object to its distance from the eye and investigates the apparent shapes of cylinders and cones when viewed from different angles. Pappus believed these results to be important in astronomy and included Euclid's Optics, along with his Phaenomena, in the Little Astronomy, a compendium of smaller works to be studied before the Syntaxis.

Ptolemy conducted a number of experiments with curved polished iron mirrors, and discussed plane, convex spherical, and concave spherical mirrors in his Optics. Parabolic mirrors were also described by the physicist Ibn Sahl in the 10th century, and Ibn al-Haytham discussed concave and convex mirrors in both cylindrical and spherical geometries, carried out a number of experiments with mirrors, and solved the problem of finding the point on a convex mirror at which a ray coming from one point is reflected to another point. By the 11th century, clear glass mirrors were being produced in Moorish Spain.

Thomas Jefferson's invention of the concave mirrors. In 1806, Jefferson ordered “a twelve inch concave glass mirror in a plain black frame” from William Jones and Samuel Jones in London.

Thomas Jefferson’s intention was to use the concave mirrors, as well as the condensing lenses and scioptic ball he had bought in London in 1786. In 1822 he wrote, “In microscopic observations, the enlargement of the angle vision may be indulged, because auxiliary light may be concentrated on the object by concave mirrors.” In other words, the focal point of the mirrors would be placed at position in which the reflecting mirror of a compound microscope would be. When the observer stands outside the focal point of a concave mirror, he or she is able to see and notice their image reflected upside down (not right side up).

Euclid discovered the law of reflection which states that light travels in straight lines and will reflect from a flat surface at the same angle that it hit. Euclid stated that light travels in rays that are individual, but appear constant because they move fast. Unlike Aristotle, Euclid believed that light is released from the eye.

Ptolemy tried to experimentally prove the law of refraction which explains how a ray of light changes direction when it travels between different mediums. This occurs because it slows down or speeds up. Refraction occurs when light hits the surface of water or if it travels through the atmosphere. Atmospheric refraction, which is, “the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of altitude” causes the stars to shine.

    In 984, Ibn Sahl, a mathematician, discovered the law of refraction that Ptolemy had been looking for. Ibn Sahl was able to show that the angle of incidence is related to the angle of refraction using the law of sines.

• Ptolemy's law of refraction:

  • angle of incidence (i) ∝ angle of refraction (r)

  • Ibn Sahl's law of refraction:

    • sine(i)   =    V1 V2

   sine(r)    n2 n1

An Italian physicist Francesco Grimaldi discovered diffraction. He showed that an individual beam of light splits into distinct directions, creating an interference pattern, if it’s shone through tiny slits. This was an essential discovery for those that supported a wave theory of light, since the sharp boundaries created by shadows implied that light could not bend around corners in the same way that sound or water waves can. Two years after his death, Grimaldi’s discoveries were published in 1665.

They are not still alive .

Other discoveries by these scientists:

1:Ptolemy made contributions to astronomy, mathematics, geography, musical theory, and optics.

2:Euclid:He is most famous for his works in geometry, inventing many of the ways we conceive of space, time, and shapes.

3:Francesco grimaldi:he built and used instruments to measure lunar mountains as well as the height of clouds, and drew an accurate map or, selenograph