> CSS the width of a pixel is defined relative to the length of each user's arm. I had to see this for myself to believe it. "The reference pixel is the visua

> CSS the width of a pixel is defined relative to the length of each user's arm. I had to see this for myself to believe it. "The reference pixel is the visual angle of one pixel on a device with a pixel density of 96dpi and a distance from the reader of an arm's length. For a nominal arm's length of 28 inches, the visual angle is therefore about 0.0213 degrees. For reading at arm's length, 1px thus corresponds to about 0.26 mm (1/96 inch)." Source: http://www.w3.org/TR/css3-values/ http://www.w3.org/TR/css3-values/