- Lived:
- 598 – c. 668 CE · Bhillamāla (Bhinmal, Rajasthan), capital of the Gurjara kingdom → by tradition, Ujjain in later life
- Field:
- mathematics and astronomy — the Brāhmapakṣa school of the siddhāntas; author of the Brāhmasphuṭasiddhānta (628) and the Khaṇḍakhādyaka (665)
- The Big Idea:
- Zero and negative numbers are not marks or defects — they are numbers, with rules. He wrote the rules down, called negatives debts and positives fortunes, and got nearly all of it right, thirteen centuries before Europe was comfortable with any of it.
- In their words:
- "Negative, taken from cipher, becomes positive; and affirmative, becomes negative. Negative, less cipher, is negative; positive, is positive; cipher, nought." (Brāhmasphuṭasiddhānta, chapter 18, in H. T. Colebrooke's 1817 translation — "cipher" is his English for zero)
- If you remember one thing:
- Every zero on your screen obeys laws first written down by a thirty-year-old in a Rajasthan desert town in 628 CE — laws that travelled to Baghdad within 150 years and to Europe through Baghdad, which is why the world calls Indian numerals "Arabic."