How to design fear, explained with 99% Invisible. Check them out here:

Correction: The correct spelling of “warning” in Persian is هشدار.

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Chances are you wouldn’t be able to recognize a biohazard even if you were looking right at one. But the biohazard symbol? It’s pretty easy to spot. Most warning icons rely on previously established objects or symbols: a general caution might use an exclamation point, and a fire warning might use an illustration of a flame. But the biohazard symbol references an idea that is much harder to picture — and in the 50 years since its invention, it has become one of the most recognizable icons on the planet. But can the meaning of a symbol like this last an eternity? A special Department of Energy project is trying to figure that out.

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This video was made in partnership with 99% Invisible, a podcast about all the thought that goes into the things we don’t think about, hosted by Roman Mars. You can find full episodes at is a news website that helps you cut through the noise and understand what's really driving the events in the headlines. Check out

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