Exile from Groggs:
It is exactly my point that you have less resistant in the air than on road surfaces, that's why we can make air travel affordable.
However, we are talking about different aircraft flying at different speeds. Even though they will be flying at different altitudes (thus, different air resistance) and different speeds (thus, different drag), the differences are not big enough to make flying at 1.8M cost about the same as flying at .85M. We sure have the technology to fly faster. There are plenty of experimental and military aircraft that have achieved speeds much higher than Concorde's 2.2M. However, we don't have the technology to make it affordable. Airlines cannot (profitably) create demand at will. Until we have the technology to make supersonic travel affordable to the general public, not just some elite groups, no supersonic jets will be mass produced.
Airlines can ask Boeing to study a 1.8M aircraft. Nevertheless, when the numbers come out, all sensible airlines will see it will not be an economically viable aircraft, at least not in the near future.