4 ms·

> 2014 travel between NYC and Chicago is only barely faster than it was over 80 years ago. Your issue is twofold: you are focusing solely on one metric to meas

by spupe 4y ago

> 2014 travel between NYC and Chicago is only barely faster than it was over 80 years ago. Your issue is twofold: you are focusing solely on one metric to measure efficiency, arguably the worst one (speed), and you then further narrow the scope by saying efficiency gains must come from one dimension of the business ("aeronautical" advances). There are obvious reasons for speed to not increase further, namely the speed of sound as you already mentioned, so this is a non-starter. We are simply not trying to make commercial planes faster anymore because that would be useless. Regarding the second point, I think it is remarkable that you present data that directly contradicts your hypothesis and fail to realize that. If we are starting more flights, carrying more people and using the same fuel, the precise definition of it is an efficiency increase. To achieve that we had improvements in booking, avionics, crew training, business models (Ryanair and other low-costs), etc. The fact that we could make a few flights at incredible cost 80 years ago does not mean that we routinely achieving far safer, cheaper and frequent flights at the same speed today is stagnation, rather the opposite in my view.

dredmorbius 4y ago
I'm given a measure, one specifically of technological capability, and one that was specifically highlighted by a significant author within the field (and whose work was cited within TFA), to make a point. I get the strong impression you don't like that point, and would prefer to use different measures. That's fine. But it doesn't invalidate the measure or point made. There are obvious reasons for speed to not increase further, namely the speed of sound as you already mentioned, so this is a non-starter. You see my point. You admit it. You state it freely yourself. And yet you reject it. SST would be useful, and is used in specific domains (satellite launches, military). On a costs/benefit commercial basis, given externalities and legal frameworks, however, technology has hit if not a dead end, then a remarkably robust barrier to further progress. The areas in which air travel has expanded, and the mechanisms by which it's done so, are notable because they are largely not related to aeronautical engineering: flight controls or power plants. There's some exception to the latter, jet engines have increase in efficiency both in terms of fuel consumption and power-to-weight ratios. But that's limited incremental improvement. (I'm pretty sure Vaclav Smil addresses this in Energy and Civilisation, as one of his power-plant efficiency curves. These tend to approach asymptotic limits with time.) Most of the efficiencies though come from smaller aircraft, economies of scale, increased load factors, some materials advances leading to lightweighting, and removal of both price and amenities lower-bounds which have made available lower-cost, but also far-less comfortable, air travel. There's also been a significant, though largely incremental over time increase in overall safety. No major breakthroughs, but chipping away at major risks with time. Some of those risks are reversing. The number of commercial aircraft downed by missile attack seems to be increasing in recent decades, at least on an absolute basis. It's still likely falling relative to total passenger miles. Still sucks to be you if you're on the wrong end of that ratio. But aeronautical engineering has hit a hard stop. Seeing and understanding that point viscerally is key to grasping the premise of technological limits. Many people seem exceedingly averse to doing so.

by spupe 4y ago

dredmorbius 4y ago

I'm given a measure, one specifically of technological capability, and one that was specifically highlighted by a significant author within the field (and whose work was cited within TFA), to make a point. I get the strong impression you don't like that point, and would prefer to use different measures. That's fine. But it doesn't invalidate the measure or point made. There are obvious reasons for speed to not increase further, namely the speed of sound as you already mentioned, so this is a non-starter. You see my point. You admit it. You state it freely yourself. And yet you reject it. SST would be useful, and is used in specific domains (satellite launches, military). On a costs/benefit commercial basis, given externalities and legal frameworks, however, technology has hit if not a dead end, then a remarkably robust barrier to further progress. The areas in which air travel has expanded, and the mechanisms by which it's done so, are notable because they are largely not related to aeronautical engineering: flight controls or power plants. There's some exception to the latter, jet engines have increase in efficiency both in terms of fuel consumption and power-to-weight ratios. But that's limited incremental improvement. (I'm pretty sure Vaclav Smil addresses this in Energy and Civilisation, as one of his power-plant efficiency curves. These tend to approach asymptotic limits with time.) Most of the efficiencies though come from smaller aircraft, economies of scale, increased load factors, some materials advances leading to lightweighting, and removal of both price and amenities lower-bounds which have made available lower-cost, but also far-less comfortable, air travel. There's also been a significant, though largely incremental over time increase in overall safety. No major breakthroughs, but chipping away at major risks with time. Some of those risks are reversing. The number of commercial aircraft downed by missile attack seems to be increasing in recent decades, at least on an absolute basis. It's still likely falling relative to total passenger miles. Still sucks to be you if you're on the wrong end of that ratio. But aeronautical engineering has hit a hard stop. Seeing and understanding that point viscerally is key to grasping the premise of technological limits. Many people seem exceedingly averse to doing so.