Why install a ball on the roof? Surprisingly, so many people don't know

Audit experts:Luo HuiqianAssociate Researcher, Institute of Physics, Chinese Academy of SciencesDo you have any friends like me? Every time I look at the scenery on the rooftop, my attention is attracted by the constantly rotating metal balls on the roof. Are everyone curious about these metal balls that frequently appear on rooftops or on the roofs of factories? What are these round and rolling guys used for, and why do they always appear on the roof?Today, let me take you all to understand the past and present lives of these little things...

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