Usually Bruce has no difficulty sourcing sound effects to gussy up the presentations but in this episode, he admits defeat and explains why he nearly resorted to sampling copyrighted songs. The topics this week include 4D materials explained by the engineer Anna Baker from Bristol University, discordant sexual orientation in identical twins from Tuesday Watts of Essex University and the 2017 people’s choice winner of the 3MT finals, Euan Doidge from the University of Edinburgh who explains how he extracts gold from electronic waste.