Topologically speaking, a human is just a donut with seven holes. It sounds like a joke, but it is a fundamental biological reality. Professor Hannah Fry and Michael Stevens explore the strange geometry of the human body, tracing how we evolved from simple tubes into complex toruses. They investigate the "design flaw" at the boundary of our existence, the fragile transition where skin meets internal lining, and ask why nature built us with so many vulnerabilities to the outside world. But before mapping our topology, Michael and Hannah tackle the instability of knowledge itself. From the suggestion our current physics is almost certainly wrong, to the edges of logic where mathematics fundamentally breaks down. Plus, they unpack the hidden psychology of symmetry: why is the human brain so obsessed with centering pictures, and what does it tell us about how we order our reality? ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠ Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Video Producer: Adam Thornton + Oli Oakley Video & Social: Bex Tyrrell Animations: Sam Benson Assistant Producer: Imee Marriott Senior Producer: Lauren Armstrong-Carter Head Of Digital: Samuel Oakley Exec Producer: Neil Fearn