Someone posted a picture on Reddit which showed a nail hammered through a solid wood block. Except notches were cut out of the block, with no apparent way to hammer in the nail. The redditor claimed that there was no “cheat” involved i.e. no glue or pieces held together.
There were many attempts and theories. Finally a Youtuber has showed us how to achieve this impossible. And it’s possible through a little know property about wood and water.