Drawing Holograms by Hand (2003)
I love this article.  My first reaction is &quot;no way!&quot;, but when you think about it it&#x27;s obvious that it must be so.<p>The hologram of a single point of light is a &quot;zone plate&quot;: concentric rings.  Move a sharp point in concentric circles on a surface and the scratches will form a zone plate which focuses light to a point.  An abrading object is just an array of sharp points, so the scratches formed by moving the object in concentric circles will focus light to an array of points, corresponding to the shape of the object: an image of the object.  Simple! (but not initially obvious.)