Ibn al-Haytham's Book of Optics

Book of Optics (Kitāb al-Manāẓir‎  in Arabic) was written in 1021 by Ibn al-Haytham in 1021. The book was first use of controlled experiments and reproducibility of its results.

The Book was translated into Latin around 1200. It was first printed in Latin in 1572 under the title Opticae Thesaurus Alhazeni Arabis Libri Septum by F. Risner.

Ibn al-Haytham was born in Basra in about 965 AD and died in Cairo in about 1040, In his autobiography he lists ninety-two of his own works, more than sixty of which have survive.

Ibn al-Haytham work reveals not only its revolutionary nature but also its comprehensiveness, touching all the known branches of optics.

The Optics of Ibn al-Haytham is the first authoritative work opposing the theory of Euclid, Ptolemy and other ancients that eye sends out rays of light and impinges on external things to view objects.

Ibn al-Haytham firmly rejected the emanation theory of vision and described how rays of light enters the eye from sources of light and from objects that reflects and refract light.

Ibn Haytham’s legacy in optics left a profound impression in the works of medieval scholars including Roger Bacon, John Pecham and Witelo and found conceptual prolongations an creative applications in the works of Renaissance artist and theorist such as Leon Battista Alberti, Lorenzo Ghiberti and Egnazio Danti.

Ibn-Haytham was aware of the structure of the eye form the view point of a physician as well as a physicist. Many anatomical names of the various parts of the eye that are used today are translations from the Arabic names given by Ibn al-Haytham in his Book of Optics.
Ibn al-Haytham's Book of Optics

James Clerk Maxwell and Maxwell’s equations

The greatest single advance in theoretical physics in the 1800s was the formulation of what are now known as Maxwell’s equations, named after the nineteenth century physicist James Clerk Maxwell.

James Clerk Maxwell (13 June 1831 – 5 November 1879) was born in Edinburgh, Scotland and was educated at his country home until he was 78 years old, when his mother died.

He attended the University of Edinburgh at the age 16, and at age 19, he went Peterhouse Cambridge but moved trinity to obtain a fellowship.

In 1856, he moved to Marischal College in Aberdeen to be near his father. In 1860, Maxwell was appointed to the chair of Natural Philosophy at King’s College in London, where he did his most productive work and from 1871 until his death.

The eponymous equations were actually developed by several physicists but it was Maxwell who determined the importance of these four equations from the many in the field of theoretical physics that completely define the entire filed of electromagnetics.

The equations first appeared in the Treatise on Electricity and Magnetism in 1873. He wrote this book was essentially to explain Faraday’s idea into a mathematical and therefore more universal form.

The publication of the Treatise on Electricity and Magnetism was the turning point in electromagnetics. It was for the first time since Oersted’s discovery of the link between electricity and magnetism that this link extended to the generation and propagation waves.

Maxwell’s four equations govern all the characteristics of magnetic and electric field. Individually there are titled:
*Ampere’s law
*Faraday’s law of induction
*Gauss; electric law
*Gauss’ magnetic

These equations are assumed to be one of the greatest achievements of the 19th century mathematics.
James Clerk Maxwell and Maxwell’s equations

Biography of Al-Jazari (1136-1206)

Badi'al-Zaman Abū al-'Izz ibn Ismā'īl ibn al-Razāz al-Jazarī was an engineer who worked in al-Jazira during the latter part of the twelfth century. He was also a craftsman, artist, and inventor.

Born in Upper Mesopotamia al-Jazari was employed, from about 1180 onwards, by the rulers of Diyar Bakr. He was in service of three consecutive Artuqid rulers:Nur al-Din Muhammad iv Arslan, Qutb al-Din Sukman ibn Muhammad and Nasir al-Din Mahmud ibn Muhammad.

His reputation rests upon his book, Kitab fi ma’rifat al-hiyal alhan-dasiyya (The Book of Knowledge of Ingenious Mechanical Devices), which composed in 1206 on the orders of his master Nasir al-Din Mahmud, a prince of the Artuqid dynasty of Diyar Bakr. It took 7 years to complete the book.

It is a compilation detailed descriptions of the construction and operation of a variety of mechanism, machines, and devices which he divides into six categories: clocks, drinking vessels, pitchers and basin, fountains and flutes, water-raising machines and miscellaneous.

The first attempt to translate this book by Wiedmann and Hawser, who translated parts of it into German in the first quarter of the twentieth century.
Biography of Al-Jazari (1136-1206)

Book of Ingenious Devices (Kitab al-Hiyal)

The Book of Ingenious Devices (Kitab al-Hiyal) published in 850 by the three Iranian brothers known as the Banu Musa.

The Banu Musa or sons of Musa were among the most important figures in the intellectuals and political life of ninth century Baghdad and played a key role in the founding and devilment of Arabic science and technology.

Three brothers were called, Muhammad, Ahmad and al-Hassan. They were working at the House of Wisdom (Bayt al-Hikma) in Baghdad, Iraq, under the Abbasid Caliphate.

The brothers were interested in geometry, mechanics, dynamics, music and astronomy and also that in order to study scientific works of classical times, they employed the service of team of translators.

The book was a large illustrated work on mechanical devices that included automata, puzzles and magic tricks.

On of the most impressive devices described in the book is also possibly the earliest example of a programmable machine: a robotic flute player.

In Book of Ingenious Devices, Ahmad described a contraption that would deliver hot and cold water, devices for digging wells and a lamp with a self-trimming wick.

The book is a document of some social significance, because it witnesses to the degree of mechanical knowledge and understanding of early Abbasid times,
Book of Ingenious Devices (Kitab al-Hiyal)

Discovery of rickets

The first scientific descriptions of rickets were written by Dr. Daniel Whistler. Whistler’s monograph on rickets was published while he was a medical student in October 1645 as his thesis for his MD degree from Leyden.

However, credit for bringing the disease to the attention of the medical world has generally been attributed to Professor Francis Glisson, whose book, De Rachitide Sive Morbo Puerili, Qui Vulgo published in 1650.

Glisson noted that the disease did not occur in chlorine younger than six months old, and occurred most frequently in children of the well-to-do rather than in those of the poorer classes.

Glisson’s treatise in rickets in s a medical classis and was the first written work on English Medicine focused on a single disease and was recognized immediately as an important source on the subject.

Rickets became a health problem in northern Europe, England and the United States during the Industrial Revolution when many people lived in urban areas with air pollution and little sunlight.

Because the disease was originally described in England, it became known as the English disease as well as rachitis and rickets.
Discovery of rickets