The number was manipulated when someone chose water as the medium through which the boat travels and chose to use feet and knots as the measures of length and speed. Use a medium with a different viscosity and density and you will get a different number. Likewise, measure your speed in meters per second and your length in meters and you will get a different number.

I still like the question I asked the other day. Was calculus invented? Or was it discovered? I was taught that Newton invented calculus so that he would have a way to explain his laws of physics. Some of you commented that the credit should go to Leibnitz, not Newton. The more interesting question, though, is whether it was invented at all. I think it might be a law of nature that was discovered, rather than invented.