How to design fear, explained with 99% Invisible. Check them out here: http://99pi.org/ Correction: The correct spelling of “warning” in Persian is هشدار. Watch the previous episode from this series: http://bit.ly/2DDIQAL Subscribe to our channel! http://goo.gl/0bsAjO 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. Read more: https://goo.gl/U82Ehn 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 http://99pi.org/ Vox.com is a news website that helps you cut through the noise and understand what's really driving the events in the headlines. Check out http://www.vox.com/ Check out our full video catalog: http://goo.gl/IZONyE Follow Vox on Twitter: http://goo.gl/XFrZ5H Or on Facebook: http://goo.gl/U2g06o