Persian language

Persian (/ˈpɜːrʒən/ or /ˈpɜːrʃən/), also known by its endonym Farsi (English: /ˈfɑːrsiː/; Persian: فارسی fārsi [fɒːɾˈsiː]), is the predominant modern descendant of Old Persian, a southwestern Iranian language within the Indo-Iranian branch of the Indo-European languages. It is primarily spoken in Iran, Afghanistan (officially known as Dari since 1958 for political reasons), and Tajikistan (officially known as Tajiki since the Soviet era for political reasons), and some other regions which historically came under Persian influence. The Persian language is classified as a continuation of Middle Persian, the official religious and literary language of Sassanid Persia, itself a continuation of Old Persian, the language of the Achaemenid Persian Empire. Persian is a pluricentric language and its grammar is similar to that of many contemporary European languages. Persian is so-called due to its origin from the capital of the Achaemenid empire, Persis (Fars or Pars), hence the name Persian (Farsi or Parsi). A Persian-speaking person may be referred to as Persophone.

Farsi (disambiguation)

Farsi is the indigenous name for the Persian language.

Farsi may also refer to:

People with the name

Kamāl al-Dīn al-Fārisī

Kamal al-Din Hasan ibn Ali ibn Hasan al-Farisi or Abu Hasan Muhammad ibn Hasan (1267– 12 January 1319, long assumed to be 1320)) (Persian: كمال‌الدين فارسی‎‎) was a prominent Muslim scientist. He made two major contributions to science, one on optics, the other on number theory. Farisi was a pupil of the great astronomer and mathematician Qutb al-Din al-Shirazi, who in turn was a pupil of Nasir al-Din Tusi.

Optics

His work on optics was prompted by a question put to him concerning the refraction of light. Shirazi advised him to consult the Book of Optics of Ibn al-Haytham (Alhacen), and Farisi made such a deep study of this treatise that Shirazi suggested that he write what is essentially a revision of that major work, which came to be called the Tanqih. Qutb al-Din Al-Shirazi himself was writing a commentary on works of Avicenna at the time.

Farisi is known for giving the first mathematically satisfactory explanation of the rainbow, and an explication of the nature of colours that reformed the theory of Ibn al-Haytham Alhazen. Farisi also "proposed a model where the ray of light from the sun was refracted twice by a water droplet, one or more reflections occurring between the two refractions." He verified this through extensive experimentation using a transparent sphere filled with water and a camera obscura.