80K views · 763 reactions | Steffen's polyhedron is a flexible concave polyhedron. Euler thought such a shape was impossible. I also show infinitesimally flexible polyhedrons and bistable polyhedrons. | Steve Mould | Facebook

🐨Cheeky little Koalas make it impossible to get any work done🐨 How cheeky are our Koalas here at Symbio, always running over to get attention, cuddles, and belly rubs from their favourite Human, 'Zookeeper Liz'. This is just a glimpse of the real-world challenges a Koala Keeper has to face each and every day🤣 Don't forget to hit that FOLLOW button to see more! | Symbio Wildlife Park

The #1 trick to make the plank 10 times more effective!