In science, there are questions that ask themselves, and questions you make up. Am afraid it is a sign of my narrowness of mind that I only find questions of the first kind interesting. This, for example, would have struck me as a fairly contrived-up thing to do; but in fact it is a clever experiment with some very interesting implications. Not the implications by the way, advertised by the opening paragraph of the news blurb.

I know the first author of the paper from elementary school. Since then we have both gone into physics, and into related subfields at that. And yes, I am pulling on knots of a sort too. Small world, isn't it?