Interesting discussion of different kinds of engines but the most important line is: “In the end, time is the enemy of the privileged few. Cost is the enemy of the masses.”
Why planes don’t fly faster
Interesting discussion of different kinds of engines but the most important line is: “In the end, time is the enemy of the privileged few. Cost is the enemy of the masses.”
Key data point is the aerodynamic instability and resulting engine inefficiency when flying at transsonic speeds (just below and above the speed of sound). Physics. It’s a b—.
Progress can be defined in all sorts of ways. What was the cost of that flight in 1967 versus now?
There’s a new supersonic-aircraft start-up, I think it’s called “Boom” or something, and I’ve heard them interviewed a couple times. I always chuckle. As cool as it would be, it’s just not possible. Moore’s law doesn’t apply to aerodynamics, thermodynamics or economics. In the end, physics always wins.
I just finished reading this book on the Skunkworks. Never thought we’d achieve stealth either, because of physics.. but then more physics made it possible. Read the story of the SR71. Incredible.. they didn’t even have the FUEL that would work (nothing was stable on the ground AND at 100k feet) needed new airframe material because of the heat. that bird cruised at supersonic. commercial supersonic is just a matter of MORE physics.. and Moore’s Law most certainly does apply… because faster computers allow for fancier fly by wire systems.. look at the F117, can’t be flown unassisted.. computers designed it, and they fly it too. faster computers let you try crazy ideas. 10 years ago, this shape might not have been possible http://boomsupersonic.com/xb-1/
Uh… it’s perfectly possible. The Concorde flew supersonic for years and the Boeing SST could have (canceled due to economic issues). There’s no physics issues in doing this.
However, there are issues with 1) sonic booms. which make it undesirable for supersonic flights over populated areas which means that they tend to only be considered for trans-oceanic flights and 2) the engineering and materials science is complex and hard.
The problem is that the benefit – time saved – only accrues to people on certain route types and is only valued by some people, For tourists flying to Japan from the West Coast it’s not important enough to save a few hours to pay the premium.
The problem isn’t the ability to fly supersonic, it’s the ability to do it inexpensively, which is what this startup is promising.
The limitations implied by physics are intractable: to fly at supersonic speeds it’s necessary to move so much air out of the way, so quickly, that far more energy is required per mile. Unless Moore’s law can lower the mass of air molecules or the cost of energy, it will remain an unsolvable problem.
I wasn’t clear in my post, but the problem is the cost factor. To lower it radically, which is what this company is promising, would require some similarly radical improvement in efficiency. My argument is that the physical barriers preventing cost-effective supersonic flight have not changed significantly in the decades since it was first achieved and are unlikely to change in the near future.