Raf Bocklandt was one of the speakers of the programme entitled 'Van Pi tot Pythagoras'. The other speakers were Arne Smeets (Radboud University), Pieter Roos (University of Twente), Arend Rensing (University of Twente) and Mariëlle Stoelinga (University of Twente).
All lectures have now been published online. You can watch Raf Bocklandt's lecture about 'how to find a hole in an invisible space' below. (In Dutch).