If you like honey on your toast at breakfast, you are ready to perform one of the simplest and most beautiful experiments in the physics of fluids. Plunge a spoon into the honey jar, take it out and then hold it vertically, several centimeters above the toast. The thin stream of falling honey does not approach the toast directly but instead builds up a whirling helical structure. In the late 1950s the resemblance to a pile of coiled rope led the first investigators of this phenomenon, George Barnes and Richard Woodcock, to call it the liquid rope-coil effect.
The three of us had long been fascinated by this effect but never found the opportunity to study it until 10 years ago, when Ribe and Bonn discovered their shared interest by chance at a scientific workshop in Paris. At the time, Bonn had a collaboration with the Institute for Advanced Studies in Basic Sciences in Zanjan, Iran, so we invited Habibi and several others—including, at different times, Ramin Golestanian, Maniya Maleki, Yasser Rahmani and Seyed Hossein Hosseini—to complete the team.