Tying Lasers Into Knots

Scientists using formal knot theory mathematics and optic technology have been able to "tie" laser light into knots in the shape of figure 8's and torus knots.  By tuning the up-and-down and side-to-side motion of the beams and using technology that is used in polarized sunglasses, the scientists were able to accomplish this feat.  The article appeared in livescience.com.