11. Velcro
Keeping on the theme of useful inventions that were discovered accidentally, here is Velcro. The sticky and flexible adhesive is the invention of Swiss engineer George de Mestral, who was inspired on a walk in the forest with his dog. Many times when walking through nature burrs will stick to certain fabrics or animal furs, and it can be hard to get them out. The strength of the burrs is exactly what de Mestral recreated in his lab. He created Velcro—the combination between the words crochet and velvet. NASA picked up the fabric and made it known for mainstream consumption and sale.