# YBC 7289

YBC 7289 係一塊巴比倫泥板，出名在佢上面寫住六十進制入面開方2嘅約略數值。開方2係一個正方形邊長同對角線長度嘅比例，係數學入面基礎而重要嘅一個常數。刻住嘅數字換轉返做10進制嘅話準確度去到6個小數位，被譽為「現時已知古代世界最準嘅運算」。[1]呢塊泥板相信係公元前1800至1600年間南美索不達米亞一個學生嘅作品。J. P. 摩根將佢捐咗畀耶魯巴比倫藏品系列

## 詮繹

1945年，Otto E. NeugebauerAbraham Sachs 首先發現呢塊泥板嘅數學意義，[2][5]「呢塊泥板展現咗古代世界最準確嘅運算」，準確度相當於十進制入邊六個小數位。[1]其他巴比倫泥板上邊有六邊形七邊形面積嘅運算，當中牽涉更加複雜嘅代數數，例如係${\displaystyle {\sqrt {3}}}$ [2]${\displaystyle {\sqrt {3}}}$ 呢個數字亦都係埃及一啲金字塔入邊嘅長度比例，不過YBC 7289上邊咁準確嘅數值顯示佢哋當年已經有能力去計呢啲數字出嚟，而唔係單憑實物比例估算。[6]

## 參考資料

1. Beery, Janet L.; Swetz, Frank J. (July 2012), "The best known old Babylonian tablet?", Convergence, Mathematical Association of America, doi:10.4169/loci003889
2. Fowler, David; Robson, Eleanor (1998), "Square root approximations in old Babylonian mathematics: YBC 7289 in context", Historia Mathematica, 25 (4): 366–378, doi:10.1006/hmat.1998.2209, MR 1662496
3. Robson, Eleanor (2007), "Mesopotamian Mathematics", 出自 Katz, Victor J. (編), The Mathematics of Egypt, Mesopotamia, China, India, and Islam: A Sourcebook, Princeton University Press, p. 143, ISBN 978-0-691-11485-9
4. Friberg, Jöran (2007), Friberg, Jöran (編), A remarkable collection of Babylonian mathematical texts, Sources and Studies in the History of Mathematics and Physical Sciences, Springer, New York, p. 211, doi:10.1007/978-0-387-48977-3, ISBN 978-0-387-34543-7, MR 2333050
5. Neugebauer, O.; Sachs, A. J. (1945), Mathematical Cuneiform Texts, American Oriental Series, American Oriental Society and the American Schools of Oriental Research, New Haven, Conn., p. 43, MR 0016320
6. Rudman, Peter S. (2007), How mathematics happened: the first 50,000 years, Prometheus Books, Amherst, NY, p. 241, ISBN 978-1-59102-477-4, MR 2329364
7. Neugebauer, O. (1975), A History of Ancient Mathematical Astronomy, Part One, Springer-Verlag, New York-Heidelberg, pp. 22–23, ISBN 978-3-642-61910-6, MR 0465672
8. Pedersen, Olaf (2011), Jones, Alexander (編), A Survey of the Almagest, Sources and Studies in the History of Mathematics and Physical Sciences, Springer, p. 57, ISBN 978-0-387-84826-6
9. Lynch, Patrick (April 11, 2016), "A 3,800-year journey from classroom to classroom", Yale News, 喺2017-10-25搵到
10. A 3D-print of ancient history: one of the most famous mathematical texts from Mesopotamia, Yale Institute for the Preservation of Cultural Heritage, January 16, 2016, 喺2017-10-25搵到
11. Kwan, Alistair (April 20, 2019), Mesopotamian tablet YBC 7289, University of Auckland, doi:10.17608/k6.auckland.6114425.v1