Picture of the week: a Sangaku

This five-meters long triple tablet was hung in 1797 in the Onnma shrine in the Aichi prefecture (Japan) and contains 30 problems. It is called a Sangaku, a mathematical ex-voto representing solved geometrical problems. A book about Sangakus is forthcoming, Sacred Mathematics: Japanese Temple Geometry. [1]

What do our friends interested in the anthropology of maths (Christophe, Helen, Hugo…) think of this interplay of religion and geometry? As for me, growing up in catholic Brittany, I have seen my share of weird ex-votos (the last one on my list was this toy boat, last June), but this tops everything else…

(found on Science News [2]).


[1] Fukagawa, H., & Rothman, T. (2008). Sacred mathematics: Japanese temple geometry. Princeton University Press.

[2] “Sacred Geometry” by Bethany Brookshire

3 Comments

  • comment-avatar
    Hugo Mercier 10 November 2008 (00:00)

    It’s funny to contrast the sense of deep intermingling of religion and science (well, mathematics and therefore reason at least) that comes from these ex-votos with the situation in Christian Europe at the same period.

  • comment-avatar
    Olivier Morin 10 November 2008 (00:00)

    Well, I’m not entirely sure the contrast is that striking. When Descartes discovered cartesian coordinates, his very first move was to pledge himself to go on a pilgrimage to Notre Dame de Lorette in thanks (which he did). It is not quite unimaginable to figure Descartes offering equations as ex-voto to Mary.

  • comment-avatar
    Charles Stafford 10 November 2008 (00:00)

    Although the anthropological study of ”number”, numeracy and numerical cultures has been fairly limited – the contrast with the anthropology of literacy is striking! – there seems to be a renewed interest in taking up these themes. For example, Jane Guyer and colleagues recently organised a large workshop on ”number as inventive frontier” at Johns Hopkins University (see herel). I’ve also published several papers recently on Chinese religion/cosmology which (like the Japanese case cited in this post) is heavily numerological in orientation. But of course there are many other recent examples …