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Comment by JumpCrisscross | Hacker News Reader

> Supersonic flight will never be more efficient than traditional flights

Efficient by what metric? Fuel use? That’s the new master of our existence, our six-proton czar?

If there is one way to kill sympathy and support for climate-change action, it’s by not only insisting but actually hoping that living standards don’t improve (or regress) because it reduces emissions.

Instead of seeing a new super-premium air-travel market that can pay for the scaling of synergic jet fuels, you’re essentially hoping that technologies that could e.g. single-handedly eliminate the organ-transplant geographic mismatch problem do not exist. I’m surprised there isn’t an element of shame to such views.

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I'm the last person you'd use climate change as an argument, I'm generally just frightened by the amount of problems that the governments will have to ignore before they can have their first commercial flight bleeding into ground flights.

It's the typical cyclist versus cars problem. I like cycling and I don't like driving and nothing will change that.

> first commercial flight bleeding into ground flights

> I like cycling and I don't like driving and nothing will change that

Nothing has to. If you started advocating for banning cars, on the other hand, you’d expect to see an anti-cycling lobby crop up.

oh I got distracted writing that, I meant real problems with supersonic flight lose relevance and start opening ways to have super sonic flights over ground just to save some time.

> super sonic flights over ground just to save some time

That’s the intention. My question is why others’ time is of so little value to you?

I don't know, I just never felt the pressure of time past the age of around 17 so I cannot relate anymore. I started to enjoy live significantly more by not worrying about such things.

Interesting. For me and I suspect many others, the relationship goes the other way. Time was of no importance when I was a child, but as an adult it is everything. I have finite time to spend with elderly parents, dying friends, and quickly growing children.

An hour I spend stuck in traffic we're at a airport is a conversation I'll never be able to have with a loved one when they're gone.

> Efficient by what metric? Fuel use? That’s the new master of our existence, our six-proton czar?

If it can be cheap at supersonic speeds, it will be much cheaper at subsonic, always. And use less fuel. The only advantage you get is speed.

Umm, this is not true. Supersonic speeds allow higher altitudes, which allows for higher efficiencies. This of course only applies if the aircraft is designed to take advantage of this, but I’m sure this one will be.

The limiting speed of subsonic aircraft is Mach .96 approximately.

For the u2, at its cruise altitude, this means about 100mph of airspeed… barely above its stall speed.

But if you go supersonic, you can break through that barrier and make use of the fact that there is much less air resistance at those altitudes. Not only that, but by riding past your shockwave, you can pick up a bit of recovered energy.

In some corners of the envelope, supersonic actually uses less fuel for the trip than Mach 0.9ish travel - which is where we fly our jetliners.

Also, we nasa has been experimenting with aerodynamic shapes that all but eliminate the sonic boom effect.

It’s not all bad.

> I’m sure this one will be.

If they are planning to make it more efficient than subsonic trips, it would be the first thing you would see in the website, or at least the FAQ. Supersonic flight is very cool, but for me this is just like Bugatti announcing a faster car for the rich, or an airline showing its first class luxury cabin: not very interesting.

I agree that this particular aircraft / project has limited potential. What I am most excited about is the potential for advancement of the field that could lead to realizing the potential benefits in supersonic transport.

It’s like props vs jets. Jet aircraft were less efficient but faster… until the altitude benefits made them more efficient and faster. Flying at the edge of space is the next step in that speed/ efficiency curve, and that is necessarily supersonic.

I would be exited if there were doing that, something really revolutionary, being faster with less fuel, or at least, flying at the same speed with less fuel. Unfortunately, it's something for the rich masquerading as an improvement for the entire world.

Still happy for the engineers working on this, they are probably having a great time designing a new aircraft.

>nasa has been experimenting with aerodynamic shapes that all but eliminate the sonic boom effect.

Yes, they've been trying to do that since the 1960s. I haven't seen any signs that they've been what I would call successful.

The x59 would have a thing or two to say about that. The sound pulse at ground level with the aircraft at altitude is about the same as a dishwasher, below the level of street traffic.

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