To expand search, see India. Laterally related topics: The Hindu-Arabic Numerals, Bhaskara, Mahaviracarya, Varahamihira, Brahmagupta, Pingala, Halayudha, The Harappan Civilization, and The Sulvasutras.
The Mathematics and the Liberal Arts pages are intended to be a resource for student research projects and for teachers interested in using the history of mathematics in their courses. Many pages focus on ethnomathematics and in the connections between mathematics and other disciplines. The notes in these pages are intended as much to evoke ideas as to indicate what the books and articles are about. They are not intended as reviews. However, some items have been reviewed in Mathematical Reviews, published by The American Mathematical Society. When the mathematical review (MR) number and reviewer are known to the author of these pages, they are given as part of the bibliographic citation. Subscribing institutions can access the more recent MR reviews online through MathSciNet.
Gerdes, P. Reconstruction and extension of lost symmetries: examples from the Tamil of South India. Symmetry 2: unifying human understanding, Part 2. Comput. Math. Appl. 17 (1989), no. 4-6, 791--813. (Reviewer: Marjorie Senechal.) SC: 01A99 (01A10 92K99), MR: 91a:01058d.
Gerdes discusses the designs drawn (or formerly drawn) by Tamil women in South India during the harvest month Margali. The author shows that some of the diagrams may be degradations of earlier patterns that display more symmetry and/or are constructed according to the cultural ideal of having only one line. Gerdes also discusses drawing algorithms; many algorithms work by applying a series of simple transformation rules to a simpler motif. The function of these diagrams appears to be religious. As the author explains, "Margali is the month in which all kinds of epidemics were supposed to occur. Their designs serve the purpose of appeasing the god Siva who presides over Margali." Closely related topics: Continuous Tracing Problems, Symmetry, and Religion.
Gerdes, Paulus P. J. On ethnomathematical research and symmetry. Symmetry in a kaleidoscope, 2. Symmetry Cult. Sci. 1 (1990), no. 2, 154--170. SC: 01A07, MR: 1 188 949.
Gerdes begins with a discussion of why symmetry is such a common phenomenon in human culture. He notes that some symmetries which are rare in nature (e.g., rotational symmetries of order 2) are common amongst us. Gerdes gives the example of rotational symmetry being used in the tattoos of the Makonde of northern Mozambique. Gerdes explains how symmetries such as the rotational symmetry of order 2 can arise naturally in solving problems in such areas as weaving. Gerdes then turns to the geometry of the line drawings made by the Tamil women in South India (during harvest month) and those made by the Tshokwe. These drawings have some strong similarities, and in both cases show an interest in tracing out a figure with a single continuous line. They also show a strong interest in symmetry, and Gerdes gives examples of how designs which fail to follow the one-line cultural norm may also fail to display the expected symmetries, suggesting that such drawings are degradations of more symmetric ones drawn with one line. The author advances a construction principle that can be used to construct both the Tamil and Tshokwe patterns. (Although the author doesn't note this, it is interesting that this principle is very similar to another principle that has been advanced for Celtic knot friezes!) Gerdes then discusses some mathematical properties of curves made using his construction principle. He also discusses some other interesting topics in his ethnomathematical research. For example, the author mentions that he has a found a new hypothesis on the origin of the Egyptian formula for the volume of a truncated pyramid, and has also found an infinite series proof for the Pythagorean theorem. Closely related topics: Symmetry, TheTshokwe, Continuous Tracing Problems, The Celts, Ancient Egypt, and Pythagorean Triangles and Triples. Also possibly relevant: Mozambique, Tattoos, and Weaving.