Noperthedron is not Rupert (can't fit through itself) [video] (youtube.com)

this video is new and an easy watch, based on this paper which has been on here before https://arxiv.org/pdf/2508.18475

and here's the Tom7 video he recommends if you want to go deeper https://www.youtube.com/watch?v=QH4MviUE0_s