The Medieval Secret That Keeps the Eiffel Tower Standing to This Day

[00:00:00]Modern bolts are trash compared to this medieval technique that keeps the Eiffel Tower standing to this day. While a standard bolt concentrates all the force on its threads and loosens with any vibration, hot riveting plays with extreme physics. Workers slam glowing red-hot iron into the hole and crush the end under brutal pressure. But the real miracle happens when it cools down. As it loses heat, the metal tries to shrink desperately. And since the ends are locked, it generates a molecular clamping force so violent that it crushes the steel plates together forever. It is a permanent pressure that [music] fuses the parts into a single solid piece. A bolt snaps or rusts, but hot riveting creates an indestructible shield that only comes off if you cut the steel.