The author’s thesis is interesting but unfortunately he makes terrible arguments for it. Here’s a completely different and much better argument:

For the past half-century, this one law has ensured that the entire field of supersonic flight has been explored by just one actor, the military, which has a completely different set of incentives and interests to all other actors in the field of flight.

Fuel efficiency, noise pollution, passengers per flight, economic benefits of faster commercial travel - the military doesn’t care about these at all. But commercial aerospace engineers care a great deal about these things, they have made huge strides in improving them*, and this law effectively completely bars all of them from investigating supersonic flight because no matter what they might discover, they will not be permitted to implement any of it. There is no way even in principle to get around this law because it does not care about anything except the speedometer reading.

( *: ”Revenue passenger kilometers per kilogram of CO2” is a statistic that tries to capture the combined effects of a wide range of efficiency improvements. Wikipedia says it has gone from 0.4 in the 1950s to 8.4 in the 2010s, a 20x improvement. https://en.wikipedia.org/wiki/Fuel_economy_in_aircraft The FAA says that in 1975, one person on the ground experienced significant noise exposure for every 30 people taking a flight. Today, one person experiences significant noise exposure for every 2,100 people taking a flight, a 70x improvement. The threshold for ‘significant noise exposure’ has not changed in this time. https://www.faa.gov/regulations_policies/policy_guidance/noi...)

For all we know there might be some particular combination of aircraft shape, speed, route, and cruising height that lets an aircraft skip along the upper surface of some obscure transition boundary in the atmosphere and you could fly a thousand passengers from London to New York in three hours using one-tenth of the fuel, and all the sound energy bounces off that boundary and is reflected into the upper atmosphere, never reaching the ground. We will never know because no company will pay any engineer to look for it because even if they found it they wouldn’t be allowed to test it, much less fly it commercially. They can’t even properly investigate it intellectually since there’s almost no research material because, again, it’s illegal in principle.

It’s hard to come up with an analogous law for other fields. It would be like banning any computation faster than one megaflop per second, because at the time of the law being passed we only had vacuum tubes and getting that speed out of a vacuum tube computer required a building the size of a football stadium and the tubes tended to explode and kill technicians. It would be like making it illegal for any person to travel at any speed greater than 20mph, because trying to go faster tended to harm the horses we were riding at the time.

We should repeal this law against supersonic flight (and replace it with an equivalent law that cares about the consequences of supersonic flight), to signal to aerospace companies that we will, in principle, let them do it - if they can do it well.