Jia Xian (Simplified Chinese: 贾宪, Traditional Chinese: 賈憲, Pinyin Alphabet: Jiǎ Xiàn, Wade-Giles /Beijing Chinese: Chia Hsien; 1010-1070) was a Chinese mathematician and astronomer. Besides the fact that he succeeded in defining Pascal's triangle in the eleventh century, he made many mathematical inventions and astronomical discoveries.
Brahmagupta (Sanskrit: ब्रह्मगुप) (598 – 668 AD) was an Indian mathematician and astronomer. He has two important works on mathematics and astronomy, the theoretical “Brāhmasphuṣasiddhānta (628)” and the more practical “Khaṇḍakhādyaka (665)”. Brahmagupta is the scientist who first gave the rules for trading with zero. Since the proofs are not offered, it is not known where Brahmagupta's mathematics was derived from.
Thales of Miletus (624-620 BC/548-545 BC) was an Ancient Greek philosopher and one of the Seven Sages of Greece. He is known for his belief that everything has a basic principle and his contributions to mathematics and astronomy, claiming that the Earth is a flat disk floating in a vast sea.
Pythagoras of Samos is a mathematician, naturalist, and philosopher who lived in Antiquity. Pythagoras, the owner of geometric and mathematical inventions, also founded the Pythagorean philosophical school. In addition, he was the first scientist who managed to formulate sounds.