Jonathan Chaika of the Institute for Advanced Study presents a joint IAS/Princeton University seminar talk on rank 1 measure preserving transformations, a flexible class of dynamical systems studied for decades. He opens with three results due to King: a rank 1 transformation's centralizer equals the weak closure of its powers, its factors are rigid so mildly mixing rank 1 transformations are prime, and mixing rank 1 transformations have minimal self-joinings. The talk's main point answers a question Thouvenot posed, whether mild mixing (the absence of rigid factors) automatically forces minimal self-joinings for rank 1 systems. Chaika, working jointly with Donald Robertson, shows it does not, constructing a mildly mixing rank 1 transformation with a joining that breaks the expected pattern. No prior background in joinings or rank 1 systems is assumed, and the talk closes with open problems in the area for those wanting to continue the line of research.