I had no idea that inhaling sulfar hexafluoride does the opposite effect of helium to your voice. Whereas helium makes your voice go higher, sulfur hexfluoride makes your voice go much deeper, making it sound like you’re speaking in a slow-motion video when you really aren’t. [via]

I’d love to see somebody inhale sulfur hexafluoride and say something really fast. And I wonder if this is how they get evil characters in movies to laugh the way they do.

Here’s one more video. Kinda neat!