This NExT PhD Workshop is the third of a series of Workshops for Graduate students. It is open to NExT Institute staff, PDRAs and students, as well as external participants. It aims to bring people together to present, share and generate new ideas. The topic of this Graduate Workshop is "At the frontier of our knowledge". This will be the topic of the lectures during the first two days of the workshop. The last day is a conference-type day with presentations especially from members of the NExT nodes.