String theory: the evolution of the tennis racket
弦理論：網球拍的演變

From 16th-century makeshift paddles to today’s masterpieces of aerodynamic design — via the controversial 1970s ‘spaghetti’ maverick — they’ve come a long way
從16世紀的臨時球拍到今天的空氣動力學設計傑作，它們已經走過了漫長的道路。