Here's a relatively useless yet undoubtedly impressive trick you can pull the next time you go to the beach: make a sand castle that's so unbelievably sturdy that it can hold up an entire person. Seriously. What's it take? Unfortunately, a wee bit more than just wet sand.
The scientific reasoning is to create enough tension of the inward force of the castle (the sand attaching itself together with water) that it could match the downward force onto the castle (the fat human on top of the castle). Matt Kuchta, the genius behind this video, used window screens to create the necessary support system inside the sand castle.