video: A video of a trefoil knot in a mechanochromic fiber being tightened. This video was recorded with the fiber immersed in an oil bath to reduce the influence of fiber drag and illuminated by diffuse light from nearly all angles with an approximate integrating sphere. Reduced drag largely eliminates the strain insulation effect observed in "Trefoil tightening_Plain," but slip-stick behavior is observed. As the knot is tightened, patches of yellow, green, and blue indicate regions of high strain in the knotted structure. This material relates to a paper that appeared in the Jan. 3, 2019 issue of Science, published by AAAS. The paper, by V.P. Patil at Massachusetts Institute of Technology in Cambridge, MA, and colleagues was titled, "Topological mechanics of knots and tangles." view more
Credit: Joseph Sandt