In quantum physics, theoretical predictions sometimes precede the observation of an entire generation of researchers. This is precisely the case of the so-called butterfly molecule. A team led by Herwig Ott at the RPTU University in Kaiserslautern-Landau (Germany) has just created and detected it, putting an end to twenty years of tracking. The results are published in Physical Review Letters by Markus Exner and his colleagues. This is the last …