Drawing a Celtic knot on a grid. The hypnotic Celtic knot might not be as complicated as it seems. Fourth-year math major Benjamin Liu, from Northampton, Mass., has broken the Celtic knot into 12 ...

Celtic knots are optical illusions. They are called “pure knots” because they appear to have no beginning or end. A new class at the Davis Arts Center will show you the secret to drawing Celtic knots ...

The hypnotic Celtic knot might not be as complicated as it seems. Fourth-year math major Benjamin Liu, from Northampton, Mass., has broken the Celtic knot into 12 standard segments that can be ...