Flags are one of the simplest yet most powerful pieces of design ever conceived. They can make us swell with pride, burn with hatred -- and even inspire people to die or kill in their name, says vexillologist Michael Green. Take a brief walk through history as Green explores the symbolic fervor behind flags that unify and divide, inviting us to imagine a future where we can come together under one collective identity: humanity.

Michael Green: How flags unite (and divide) us

How flags unite (and divide) us

Flags, embodying the essence of national pride, can also become divisive symbols, shaping our perceptions of unity and exclusion.

Flags provoke deep emotions, symbolizing unity or division, evoking pride or hatred, and even inspiring life or death actions.

Exploring flags' dual power to unite and divide, the talk delves into historical symbols, urging a future under a unified Earth flag.