Portal:Paris/Did you know
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Did you know that it isn't the wind that is the greatest and most constant mover of the Eiffel Tower, but the sun?
Metal expands when heated, and on clear days the sun makes the iron girders exposed directly to its glare grow enough to make the tower lean 6-18 cm away from it. The tower of course returns to its neutral vertical state after sunset.
The wind has never made the tower oscillate more than 18 cm, and this during a 169.2 km/h gale measured during the storm which has swept across Central Europe on 26 December 1999.
