Saturday April 19, 2008 7:00 am Lismore NSW

It has been over 2 weeks since I last did any mathematics. I have now reread chapters 1 & 2, and read chapter 3 of "Symmetry" by du Sautoy.

I have not yet used my fountain pen and Rhodia notepad to make any notes. I have also not used my camera to take any photos of symmetric objects. I might be able to blame the rain for the latter but that still leaves me looking for an excuse for the writing.

Here is my chart of symmetry readings: Each cell will corresponds to a chapter. Yellow indicates the number of chapters in the book, green indicates that I have read and made notes on the chapter.

Now to make a few notes on chapter 3 of "Symmetry".

1. I must make an effort to visit this palace in Spain.

2. I need to understand what these 17 symmetries are. I think the Stevens book will be useful but that will have to wait until I am back in Lethbridge.

3. I might try a treasure hunt of my own and see if I can find examples of all 17 symmetries anywhere.

This is a critical point. I wonder what notation Stevens uses. I also need to find a description of Conway's notational system. Are there others? Does Stevens use the same notation as crystallographers?

At the moment I am reading about mathematics, but I am not doing any mathematics, nor am I really learning any mathematics. I am more of a voyeur reading about someone else doing mathematics. Not as good as being really involved.

I am not sure that I knew this. I may have, but if someone had said to me that the Arabs had invented zero I doubt that I would have noticed the discrepancy.

The remainder of this chapter describes many of the symmetries that du Sautoy sees at the Alhambra, but there is not a systematic description of all 17 plane symmetries, nor is there a complete description of Conway's notational system.

I do not have any resources at hand at the moment to clarify this. I will continue reading du Sautoy but will focus on really understanding these 17 symmetries as soon as I am home. This is not a problem as it is often a good idea to get a general idea of what one is trying to learn and then go back and focus on the details.

Now to add one more green cell to my matrix of symmetry readings. Done.

This has been a great way to begin the day. The rain is beating down on the roof, I have a hot cup of coffee by my side, and I am engaging in a very interesting book.