Our experiences of the world are diverse, often changing as we move across borders from one country to another. They can also vary based on language or subtle shifts in climate. Yet, we rarely consider what causes these differences and divisions. 

In this episode we speak to geographer Maxim Samson at De Paul University in the US about the unseen boundaries that can shape our collective and personal perceptions of the world – what he calls "invisible lines".

This episode was written and produced by Mend Mariwany with assistance from Katie Flood. Eloise Stevens does our sound design, and our theme music is by Neeta Sarl. Gemma Ware is the executive producer. Full credits available here. A transcript is available now. Subscribe to a free daily newsletter from The Conversation.

Further reading

• Removing urban highways can improve neighborhoods blighted by decades of racist policies
• Wallacea is a living laboratory of Earth’s evolution – and its wildlife, forests and reefs will be devastated unless we all act
• Africa’s got plans for a Great Green Wall: why the idea needs a rethink