Optics

Ibn Sahl 984 Laws of refraction

Ibn al-Haytham (Alhazen) Book of optics 1011-21. Ray theories of light Human Visual System Development of Optical Technology

Behavior of light through a pin-hole

~300 BCEuclid (Alexandria) In his Optica he noted that light travels in straight lines and described the law of reflection. He believed that vision involves rays going from the eyes to the object seen 965-1020Ibn-al-Haitham ~1267Roger Bacon (England) speed of light is finite and that it is propagated through a medium in a manner analogous to the propagation of sound 1303Bernard of Gordon (France). A Physician, he mentioned the use of spectacles as a way of correcting long-sightedness ~1590Zacharius Jensen (Netherlands). Constructed a compound microscope with a converging objective lens and a diverging eye lens 1604Johannes Kepler (Germany). In his book Ad Vitellionem Paralipomena, Kepler suggested that the intensity of light from a point source varies inversely with the square of the distance from the source 1608Hans Lippershey (Netherlands). Constructed a telescope with a converging objective lens and a diverging eye lens 1610Galileo Galilei (Italy). Using his telescope, Galileo reported several astronomical discoveries including that Jupiter has four moons 1666Isaac Newton (England). Described the splitting up of white light into its component colours when it is passed through a prism 1865James Clerk Maxwell (Scotland). concluded that light is a form of electromagnetic wave 1887Heinrich Hertz (Germany). Accidentally discovered the photoelectric effect 1905Albert Einstein (Germany). Explained the photoelectric effect on the basis that light is quantized, the quanta subsequently becoming known as photons 1900Max Karl Planck (Germany). Constant 1913Neils Henrik David Bohr (Denmark). Atomic energy 1948Dennis Gabor ( b.Hungary). Described the principles of wavefront reconstruction, later to become known as holography 1958Arthur L Schawlow and Charles H Townes (USA). Laser

Electromagnetic Spectrum

Nimrud Lens 7th C BC

1st Painting showing spectacles 1352 1353 1410 1st Painting showing spectacles 1352

1635 ATHANASIUS KIRCHER (1602 - 1680)Kircher was a scholar at Rome who was made professor of mathematics. He observed the sun using the camera obscura.

Illustration from Ars Magna Lucis et Umbrae, Athanasius Kircher's seminal 1646 treatise on light and shadow. In explaining the principle of the camera obscura, the illustration associates the image and the shadow with the devil.

Camera Obscura

Table of Optics 1728

Joseph Nicephore Niepce 1822

First Daguerreotype 1837

Equipment for making daguerreotypes from an ad 1843

Louis Jacques Daguerre (1787-1851) - London 1847

Robert Cornelius's 1839 self-portrait