Anna Skorobogatova of ETH Zürich presents a seminar talk at the Institute for Advanced Study on optimal bubble cluster problems, the question of how to partition space into chambers of prescribed volume while minimizing the total interfacial area between them. She reviews the classical multiple bubble problem, where Sullivan's conjecture predicts a unique minimizing configuration in low dimensions, and the variant studied by Bronsard and Novack involving more than one infinite-volume chamber. Skorobogatova then presents her own result, joint work with Lia Bronsard, Robin Neumayer, and Michael Novack, showing that uniqueness of local minimizers fails once the ambient dimension reaches 8 or higher, with specific configurations illustrating the unexpected behavior that appears there. The talk is aimed at an audience already versed in geometric measure theory and minimal surface theory, moving directly into technical constructions and counterexamples rather than offering a general introduction. It runs just over an hour and was recorded for the IAS Analysis and Mathematical Physics series.