Sand castles aren't exactly the most secure structures out there. Something as light as a Pomeranian's paw can take them down like an earthquake, and a wave of a kid's Popsicle stick can send them crumbling.
That's why a video from the Practical Engineering YouTube account posted Monday is so fascinating. In a little less than eight minutes, the narrator delivers a master class on how to reinforce simple soil by layering in stronger materials. Even a few layers of something as light as paper towels help him make a small sand tower strong enough to support a brick. And as his layering materials toughen up, so does the strength of his sand blocks.
By the end of the video, you may still not feel safe resting a car on a block of sand, but you may pick up some tips to help your kid build a better castle on that next trip to the beach.
(Via Popular Mechanics)