@in_visible_world: Is the ball in or out? I'm currently tuned in to the @ATP Tour and got curious about exploring the intricate world within a tennis ball. These fascinating images, captured via a Scanning Electron Microscope, unveiled something truly intriguing. The fibers within resemble the structure of hair. Well, it turns out that most professional tennis balls are crafted with authentic felt, often derived from sheep wool fibers. Quite an interesting fact, isn't it? Enjoy the ATP finals along with this newfound insight! #microscope #macro #micro #closeup #sport #tennis #atpfinals #sinner #ball #tennisball #explore #learn #howitsmade #NittoATPFinals #alcaraz #invisibleworld #microscopy