There is no universally accepted definition of a mountain. Elevation, volume, relief, steepness, spacing and continuity have been used as criteria for defining a mountain. In the Oxford English Dictio ...
Main article: PetrologyIn addition to identifying rocks in the field, petrologists identify rock samples in the laboratory. Two of the primary methods for identifying rocks in the laboratory are throu ...
Main articles: History of the Earth and Geologic time scaleThe geologic time scale encompasses the history of the Earth. It is bracketed at the old end by the dates of the earliest solar system materi ...
Given a spherical model,\begin{align}x = \lambda \cos \varphi_1\\y = \varphi\end{align}where\scriptstyle\lambda is the longitude;\scriptstyle\varphi is the latitude;\scriptstyle\varphi_1 are the stand ...
Balkh is considered to be the first city to which the Indo-Iranian tribes moved from the North of Amu Darya, between 2000 – 1500 BC. The Arabs called it Umm Al-Belaad or Mother of Cities due to its a ...
Ibn al-Faqih al-Hamadani (Persian: ??? ???? ?????????) was a 10th-century Persian historian and geographer, famous for his Mukhtasar Kitab al-Buldan ("Concise Book of Lands"). ...
Via the Triangle Area Formula The area T of any triangle can be written as one half of its base times its height. Depending up which side one chooses to be the base, the area can be written as any ofT ...
Abu Nasr Mansur ibn Ali ibn Iraq (Persian: ??? ??? ????? ?? ??? ?? ?????; c. 960 – 1036) was a Persian Muslim mathematician. He is well known for his work with the spherical si ...
Because astronomical objects are at such remote distances, casual observation of the sky offers no information on the actual distances. All objects seem equally far away, as if fixed to the inside of ...
While it may have been used by ancient Egyptians for star maps in some holy books, the earliest text describing the azimuthal equidistant projection is an 11th-century work by al-Biruni.The projection ...
He was born in the outer district of Kath, the capital of the Afrighid dynasty of Khwarezm (or Chorasmia). The word Biruni means "from the outer-district" in Persian, and so this became his nisba: "al ...
It was Estakhri who created the earliest known account of windmills. His Arabic language works included masalik al-mamalik (????? ???????, "Traditions of Countries") and Suwar al-Aqaaleem ...
Of the many books ascribed to him in the al-Fihrist by Ibn al-Nadim, one can note the excellency of mathematics; on certitude in astrology. His Figures of the Climates (Suwar al-aqalim) consisted chie ...
Abu'l-Qasim Ubaydallah ibn Abdallah ibn Khordadbeh (Persian: ????????? ???????? ??? ????????) (c. 820 – 912 CE), better known as Ibn Khordadbeh, was the author of the earl ...
Al-Khwārizmī wrote several other works including a treatise on the Hebrew calendar (Risāla fi istikhrāj ta?rīkh al-yahūd "Extraction of the Jewish Era"). It describes the 19-year intercalation ...
