Thermodynamics is an interesting one, because the theory was created to explain the reality of steam engines, a commercial invention. At the time of the first steam engines (Newcomen's is a good starting point), the most popular theories (Aristotle's) declared that there could not be a vacuum.

I would also suggest that computing began no later than Babbage; Turing definitely contributed to the field, but Babbage and Clement kicked it off (largely with government funding).