موسوعة العلمـاء و المخترعين .. العلمـاء بالترتيب حسب اسم الشهرة .. الحرف خ

Encyclopedia of Scientists and Inventors.. Scientists in order according to their nickname.. The letter Kh

⏹Khaladni, Ernst Florence Friedrich
Chladni Ernst Florens Friedrich

German physicist (1756 - 1827)
Khaldani began studying law, then turned to science and became a pioneer in the science of sound. He earned his living by playing music and lecturing in science. Khaladani invented a musical instrument known as the “euphonium.” He discovered the long waves and called by his name “Khaladni shapes, which are the shapes arising in the sand covering discs that are subject to vibration.” The result of rubbing it with the bow of the violin, and Khaldani is considered one of the founders of the science of sound.

⏹ Al-Khwarizmi, Abu Abdullah bin Musa
al-Khawarizmi

Islamic mathematician and astronomer (000, 846)
Originally from Khiva, south of Lake Aral in Turkestan
He lived in Baghdad during the days of al-Ma'mun.
Al-Khwarizmi is a brilliant scientist in mathematics, astronomy, geography, and history, and he combined Indian science with Greek science. He was the first to write a book on algebra independent of arithmetic. And about engineering. Al-Khwarizmi coined the word Algebra and became attributed to him.
The most famous and most important of his books: Algebra and the interview. Al-Khwarizmi wrote a summary of this book to be accessible to people in their commercial activities.
Al-Khwarizmi introduced the Arabs and Westerners to the Indian numbering system. It is believed that the term "Algorism" is derived from its name among Western Latin writers.