Suggestions for topics in a public talk about art and mathematics I've been giving a public talk about Art and Mathematics for a few years now as part of my University's outreach program. Audience members are usually well-educated but may not have much knowledge of math. I've been concentrating on explaining Richard Taylor's analysis of Jackson Pollock's work using fractal dimension, but I'm looking to revise the talk, and wonder if anyone has some good ideas about what might go in it. M.C. Escher and Helaman Ferguson's work are some obvious possibilities, but I'd like to hear other ideas.
Edit: I'd like to thank the community for their suggestions, and report back that Kaplan and Bosch's TSP art was a real crowd pleaser. The audience was fascinated by the idea that the Mona Lisa picture was traced out by a single intricate line. I also mentioned Tony Robbin and George Hart, which were well-received as well.
 A: I also can't resist mentioning Kaplan and Bosch's work using the traveling salesman problem to reproduce famous artworks; i.e., TSP art.  See these links:
http://www.cgl.uwaterloo.ca/~csk/projects/tsp/
http://www.oberlin.edu/math/faculty/bosch/tspart-page.html
http://www.tsp.gatech.edu/data/art/index.html
For example, this reproduction of the Mona Lisa is actually a solution to a traveling salesman problem.  There's a single path that creates the image. 

A: There is a lot of beautiful mathematics (mostly, if not all geometry) in perspective drawing.  I've heard Annalisa Crannell give beautiful lectures on this.  Unfortunately, her book isn't due out until July 2011 (you can find it on amazon, and I can only include one link).  There is a nice description of a public lecture she gave at the MAA, with audio of the lecture and a few embedded videos:
http://maa.org/news/092310Crannell.html
A: You might get some inspiration from the articles in the Journal of Mathematics and the Arts (published by Taylor and Francis -  http://www.informaworld.com/smpp/title~content=t755420531~db=all) and/or from the proceedings of the Bridges Conferences (which deal with connections between mathematics and the arts) - http://www.bridgesmathart.org/
A: The influence of the 4th dimension on art. Duchamp is an obvious example. Art historian Linda Henderson believes that Picasso was 4-dimensionally influenced as does  Tony Robbin  who clearly and unabashedly is. Tony's work influenced me to draw a bunch of stuff at  my website,  and these drawings are directly influencing some of the mathematics that I am doing. In addition, you might want to mention Carlos Seguin (sic?) and of course, George Hart. His daughter Vi Hart has been in the news recently. 
The problem is not that there is a lack of material, but there is too much. Many great and serious artists are influenced by us, and as I indicated above some of us are influenced by them. You should also look at the work of Radmila Sazdonovic and Slavan Jablan for example.  
A: I heard Thomas Banchoff give a nice talk about Salvador Dali's work a few years ago.  Apparently they were even friends.  
Here's a link to a lecture by Banchoff on Dali.
It looks like Banchoff wrote a paper in Spanish Catalan on Dali, too: 
"La Quarta Dimensio i Salvador Dali,"  Breu Viatge al mon de la Mathematica, 1 (1984), pp. 19-24. 
Even with my poor Spanish nonexistent Catalan skills I can translate the title as "The Fourth Dimension and (or "in"?) Salvador Dali." :)
A: The golden ratio in architecture.  I saw an interesting talk on this at Union College.  They're fond of the golden ratio because of the Nott Memorial.  There are a number of ratios, e.g. diameter to height, that approximate the golden ratio.  The ratio is also incorporated into the design of the Gothic arches.
