The Eiffel Tower grows 15 cm taller in summer
Metal expands when heated. The iron structure of the Eiffel Tower expands by about 15 centimetres (6 inches) during hot summer months as the iron heats and its atoms vibrate more, pushing further apart. This thermal expansion is why bridges have small gaps built in — engineers deliberately leave space for metal to expand and contract without warping. The Eiffel Tower's top can also lean up to 18 cm away from the sun on very hot days.
We think of iron as a fixed, rigid material. Discovering that a famous landmark is literally a different height depending on the season challenges that assumption.
“The Eiffel Tower grows 15 cm taller every summer because iron expands when heated. The top can even lean away from the sun on hot days. 🗼 #OddlyHuman”