Did you know the iconic yellow smiley face was first designed in 1963? However, its creator, Harvey Ball, soon worried that the symbol had become over-commercialised. To counter this, he introduced World Smile Day in 1999, celebrated on the first Friday of October, as a way to encourage acts of kindness and spread smiles. In the spirit of making you smile, the Unexpected Elements team has gathered science stories that bring them joy—each with a twist, of course. Children across cultures have invented secret languages to confuse their parents—and there's science behind it. The human face can produce 19 different types of smiles. And let’s not forget the Brazilian scientist who not only pioneered species classification but also became a key figure in the country's suffragette movement. Meanwhile, Marnie Chesterton introduces us to the ever-cheerful Professor Andrea Sella from University College London, whose humour never fails to brighten her day. Together, they explore the role of humour in science and its importance in engaging both audiences and students. Plus, we’ll dive into the science of vocal fingerprints, meet a man who physically couldn’t smile, and hear about a global update to cyber security regulations that just might make you grin. Happy Friday! Presenters: Marnie Chesterton with Andrada Fiscutean and Camilla Mota Producers: Harrison Lewis with Jonathan Blackwell, Elizabeth Barsotti, and Anna Charalambou.