The Concorde tool he used "can find the exact optimal path" but I can't tell from the documentation what it returns if it cannot definitely find the shortest path; perhaps it does the best it can. We don't see how Mr. Mehyar used it because he skips a step in his wonderful report: Apparently TSPs with a large number of nodes can be definitively solved, and this has been true for some time. I would be surprised if the Concorde program would report a path as the definite solution when there is still some doubt, but I can't believe that what looks like the long way around New Mexico is actually the shortest path.Am I missing something or is he wrong?
He says this is "the optimal path that I found," which might be understood to mean that it is not the optimal path, but he also says he was "most interested in finding the exact optimum." [13] # create input file for Concorde TSP solver
[14] # after running the Concorde executable, parse the output fileThere wasn't a big difference between planar and geodesic
At 35°N, over a few hundred miles, I wouldn't expect much projection error. A flight plotter shows very minimal curvature.