Galileo tried to convince church leaders of the correctness of the Copernican Theory. He had difficulties because the leading thinkers of his day couldn't believe in the rotation of the earth on its axis. They thought that a spinning earth would be easily felt and the earth must be stationary. In normal day to day life we don't feel the earth rotating. Could we ever "feel" the rotation of the earth if it rotated on its axis every 24 minutes instead of 24 hours? I am not talking about how the evolution of life on earth would be different or the weather patterns would be different if it rotated much faster, but pure mechanics of doing things. like walking down the street or driving a car. Is there any rotational speed that would throw people off the earth's surface, like a child thrown from a merry-go-round, if the earth rotated faster?