23/7: Slo-Mo Guys' Dan Chilling Inside A Giant Water Balloon (YouTube)
Now THIS is a WTF photo. What you're looking at is a still of the weirdest experiment ever. The Slow Mo Guys, Gav and Dan, wanted to see how much water you could fit in a giant water balloon before it burst. The twist? Dan is inside the balloon. Like, of course. Why wouldn't he be. This is the moment that the balloon explodes and, holy guac, it's hard to look away.