PROMISEs, fulfillments, and prospects

We give a survey about the recent experiments on the helical magnetorotational instability (MRI) in the framework of the Potsdam ROssendorf Magnetic InStability Experiment (PROMISE). By comparing the experimental results with numerical simulations we show that the observed instability is indeed a global instability rather than a noise-triggered convective one. We also delineate the plans for further experiments on the azimuthal MRI and on the Tayler instability.