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The corresponding sona reflect the paths that light would follow starting near one corner ( S in the diagrams , right ) and traveling at an angle of 45 degrees and bouncing off the walls . If the interval between starts is longer than the typical time to run a course , no pack forms . In the latest twist , statistician Allan R. Wilks and his collaborators at AT & T Labs in Florham Park , N.J ., have found a remarkable formula relating the curvatures and coordinates of tangent circles . In a letter of November 1643 to Princess Elisabeth of Bohemia , Descartes developed a formula relating the curvatures of four circles , each of which touch all of the other three . Homeland Security Department spokesman Russ Knocke denied the allegations , terming them inaccurate and unfair . Cholesterol is a major part of the deposits that can narrow arteries throughout your body , including those that supply your heart .