''Sullam al-sama, also known as Resaleh-ye Kamaliyyeh (

Arabic Arabic (, ' ; , ' or ) is a Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C. E.Watson; Walter ...

*: سُلَم السماء, Transliterated as Sǒllam os-Samā'), meaning "''The Ladder of the Sky''" or "''The Stairway of Heaven''", is an

astronomical Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxi ...

treatise written by the

Persian Persian may refer to: * People and things from Iran, historically called ''Persia'' in the English language ** Persians, the majority ethnic group in Iran, not to be conflated with the Iranic peoples ** Persian language, an Iranian language of the ...

mathematician and astronomer

Jamshid Kashani Ghiyāth al-Dīn Jamshīd Masʿūd al-Kāshī (or al-Kāshānī) ( fa, غیاث الدین جمشید کاشانی ''Ghiyās-ud-dīn Jamshīd Kāshānī'') (c. 1380 Kashan, Iran – 22 June 1429 Samarkand, Transoxania) was a Persian astronomer ...

in 1407 about the determination of the distance and size of heavenly bodies such as the

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

, the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

and the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

The text

Kashani finished writing the book on 1 March 1407. He mentioned in the preface of another book of his, ''Meftah al-Hesab'' (lit. "The Key of Arithmetic"), that: "I studied all books on astronomy that the scientists had written before me and I realized that they had many difficulties and disagreements about the determination of the size or distance of the astronomical objects like Mercury or

Venus Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never f ...

to the Sun. So I decided to write this book and I named it Sullam al-sama' to be a guide for the wise."

Series adaptation

The book shares its title with a TV series about Kashani produced in Iran in 2008.

Footnotes

{{Islamic astronomy 1407 books 15th-century Arabic books Iranian books Astronomical works of the medieval Islamic world