[Apes]

Not sure why all these people are saying it totally makes sense that technology can provide a magic 10x improvement in efficiency.

If you want to go the same distance for 1/10th the cost, you need to use 1/10th the fuel, have 1/10th the maintenance overhead, and have 1/10th the staffing cost all at the same time.

You can't go over 100% efficiency in any area, so to see 1/10th the cost you would need the entire aircraft industry in the 1970s to be operating at under 10% efficiency, a low bar I am highly skeptical of.

It's not like Aeronautics engineers or the Airline industries were gorillas banging rocks together with no understanding of what they were doing, and I find it hard to believe there is enough room for a 10x increase in efficiency from the 1970s even with a perfectly efficient aircraft and airline behind it.

But hey, if you really believe it's possible, invest in Boom because they must have designed a cold fusion reactor running on tap water to power their jet and everyone who invests will probably become a trillionaire overnight once they reveal it.

[fanzhang]

Is it possible that in a regulated airline market $20k roundtrip went not into the marginal physical costs but regulatory overhead/profits/recovering fixed costs? If I showed you that a can of Coke in a Disney world vending machine was $3, and told you I could get a can at $0.30, would I have performed a miracle in the soda sciences?

$8K is a normal RT JFK-LHR ticket today in business class. This is vs $800 in economy. However, Boom proposes that the same $8K can support economy-style seating traveling at Mach 2.2 instead of mach .80. It does not seem unreasonable to me that 3x the speed will cost ~10x as much.

[vasco]

That depends on the proportions of the costs, if one area is much larger in absolute values, you can go higher than 10x improvement there, while keeping all other costs equal, while still getting an overall 10x improvement. Amdahl's law yada, yada.

[SideburnsOfDoom]

> Not sure why all these people are saying it totally makes sense that technology can provide a magic 10x improvement in efficiency.

People who have worked in computing all their lives will have seen multiple "magic 10x improvement" cycles, so might have an implicit believe that it will happen everywhere.

But one should not assume that this will happen for the task of pushing big metal tubes through the air by burning things. The physics of it is not on the side of easy 10x improvements in that case.

[gaius]

If you want to go the same distance for 1/10th the cost

And remember that both BA and Air France got their Concordes “for free”

[keymone]

In 50s cars were 15mpg in average. Today’s top tier mpg cars are over 120mpg. Order of magnitude. They are also safer, quieter, faster, cheaper in maintenance, etc.

Technology does enable 10x improvements over half a century sometimes.

[brandmeyer]

You just compared fleet average in one time period to an extreme outlier in another time period.

In reality, fleet average fuel economy has been nearly flat for four decades, with the biggest periods of movement being driven by brief excursions in the price of crude oil. Those efficiency excursions were in turn driven not by technological improvement, but by changes in the makeup of the vehicle fleets themselves (lighter cars, smaller engines).

https://en.wikipedia.org/wiki/Corporate_average_fuel_economy

[keymone]

and here we're comparing "average" of supersonic flight half a century ago to a potential future outlier. i don't think i'm being outrageously unreasonable here.

[opencl]

The Concorde is not "average", it is the most fuel efficient supersonic aircraft to date by a huge margin. Yes it's kind of old but I think you are dramatically overestimating how much aircraft turbojet engines have improved in the past 40 years.

[gsnedders]

While Concorde was efficient at supersonic cruise, it was ridiculously inefficient getting there (and this was one of the main arguments for the proposed Concorde B).

Also note most aircraft capable of supersonic cruise nowadays don't use turbojets, they use low-bypass turbofans (mostly around 0.3:1).

[keymone]

turbojet is not the only thing that can be improved to reach the overall 10x.