It all started when a Twitter user floated a simple hypothesis about their sneakers.

A user with the handle @Ibelievthehype noticed that her Vans shoes always landed upright after she tossed them across the room. She shared a video of a pair of shoes being flung in the air and landing sole-side down.

The video went viral and soon the internet was flooded with others chucking their Vans shoes across floors with the hashtag #VansChallenge. And just like that, another internet challenge was born.

It did not stop there. When their Vans shoes failed them, some people used the same method to find out that the shape of their Crocs footwear means they too land face up. These videos are now being shared with the #CrocsChallenge.

Not everyone had the same results, however, showing that it’s not exactly a precise scientific fact.