If you've been on social media lately, you may have stumbled across some unusual videos of people throwing things.
It started a few days ago, with parents and older siblings tossing slices of cheese at babies and filming their reaction.
But this week we've moved on from cheese, and people are now chucking shoes about the place - and there's a rather interesting reason why.
According to a Twitter user named Bernard Pereda, pairs of Vans trainers always land right side up, no matter how you throw them.
The user filmed himself throwing different pairs of Vans 10 times and each time the shoes landed the right way up.
He threw them at walls, at shelves, over the top of doors, down corridors and each time the test had the same result.
Bernard captioned the post: "Currently testing out the hypothesis that Vans will always land right side up."
His post garnered a lot of attention, getting over 300,000 likes and 137,000 retweets. Star Wars actor Mark Hamill was among those who liked the video.
People were quick to try it out for themselves, with many experiencing the same results.
One person said: "Gosh, the internet is an amazing place."
Another wrote: "My brother works at Vans and he can confirm. The reason why they land like this is because Vans' shoes have heavy soles - according to him."
But not everyone found the theory to be successful.
So it wasn't long before Twitter users began to experiment with other types of shoes - including Crocs.
Thus the Crocs challenge was born, which has seen people filming themselves throwing Crocs around, and unlike with Vans, each Crocs video does show the controversial shoes landing the right way up.
"I'll see your Vans and raise you Crocs," commented one user.
Another added: "Mind blown... it works with Crocs too!!"
