Short answers, pulled from the story.
The origin of the spinning wheel is disputed among historians. Arnold Pacey and Irfan Habib place the most likely invention in the Middle East by the early 11th century, with clear evidence of use by 1030 and the earliest known illustration from Baghdad in 1237. Dieter Kuhn and Weiji Cheng argue for Zhou dynasty China in the first millennium BCE, while C. Wayne Smith and J. Tom Cothren propose India as early as 500 to 1000 AD.
The spinning wheel increased the productivity of thread-making by a factor of greater than ten. Before it existed, at least five spinners were needed to supply a single weaver on the eve of the Industrial Revolution. It also laid the foundations for the spinning jenny and spinning frame, which eventually displaced it during the Industrial Revolution.
The charkha became the central symbol of the Indian independence movement. Starting in 1931, it appeared as the primary symbol on the flag of the Provisional Government of Free India, and earlier versions of the Flag of India carried its image. Mahatma Gandhi framed hand spinning as a patriotic duty and explained to Charlie Chaplin in 1931 that boycotting machinery-made goods was the path to freeing India from economic dependence on England.
A treadle was said to have been added in 1533 by a citizen of Brunswick, allowing the spinner to rotate the spindle with one foot while both hands remained free to work the fiber. By the 16th century, a treadle wheel fitted with a flyer was in common use across Europe under names including the Saxony wheel and the flax wheel.
Franz Schubert composed "Gretchen am Spinnrade" in 1814, a lied based on a poem from Goethe's Faust in which the piano part evokes a woman spinning at her wheel. Antonin Dvorak composed The Golden Spinning Wheel as a symphonic poem, and Camille Saint-Saens wrote Le Rouet d'Omphale, a symphonic poem in A major, Opus 31, based on the story of Omphale and Heracles.
According to Mark Elvin, the water-powered spinning wheel described in 14th-century Chinese technical manuals fell out of use when fiber production shifted from hemp to cotton, and it was forgotten by the 17th century. Elvin treats this decline as a key part of his high-level equilibrium trap theory, which explains why China did not develop an indigenous Industrial Revolution despite high levels of wealth and scientific knowledge.