It was in Ian Stewart's column "Mathematical Recreations" in Scientific American, pages 104-106, (1991).
Stewart's article was based on a paper by the mathematician
Kenneth Falconer. As far as I am aware the article by Ian Stewart is the first time a discussion about digital sundials appears in print.
The paper by Falconer is Sets with prescribed projections and Nikodym sets and was orginally published in the Proceeding of the London Mathematical Society 53 (1986), pages 48-64. The paper
is concerned with a much more abstruse mathematical problem but, in everyday language, essentially describes a method to construct
an object so that its shadows are any prescribed shape you wish at different times of the day. Of course, being a pure mathematics paper, the method given is completely impractical...
Slashdot Mirror
It was in Ian Stewart's column "Mathematical Recreations" in Scientific American, pages 104-106, (1991). Stewart's article was based on a paper by the mathematician Kenneth Falconer. As far as I am aware the article by Ian Stewart is the first time a discussion about digital sundials appears in print.
The paper by Falconer is Sets with prescribed projections and Nikodym sets and was orginally published in the Proceeding of the London Mathematical Society 53 (1986), pages 48-64. The paper is concerned with a much more abstruse mathematical problem but, in everyday language, essentially describes a method to construct an object so that its shadows are any prescribed shape you wish at different times of the day. Of course, being a pure mathematics paper, the method given is completely impractical...
The `lone researcher' is Professor Joshua Silver of Oxford University. The company he formed can be found at http://www.adaptive-eyecare.com/ .