Hacker News Reader

Comment by kafkaesq | Hacker News Reader

Did you understand my question?

I was referring to CO2 impact, not price.

My uninformed understanding/guess: Flight is low margin and fuel is the primary cost. So you can make an estimate of the CO2 impact; if the average seat price on a normal airliner for that journey is $1000 and the average seat price on this aircraft is $5000 then I think you can say it's approximately 5x the impact.

Happy to be shown wrong, this is complete conjecture.

That would seem to make sense, to a first order approximation.

But there may be other factors to consider: type of fuel that gets burned (and how it is burned); how long it stays in the upper atmosphere (possibly at higher altitudes), etc.

Well, you did say, "they'll finally get to afford a ride on one of these contraptions." So initially I was addressing the cost part of your comment.

And you also said, "I'm not sure this is something to cheer, just because it's new and shiny." So I was addressing that part of your comment in stating that people are excited about it for more than vanity reasons.

And you talked about CO2 impact as well, to which I replied, "In any case, despite it holding fewer passengers than a Boeing 787 or something, I would bet that drastically decreasing flight time goes a long way toward bringing the carbon impact more in line with a typical flight of the same length." Carbon is one of the components of CO2 and phrases like "carbon impact" typically encompass things like CO2 generation.

So, to answer your question directly: Yes, I did understand your question. I addressed your question in my original comment, and addressed your side comments where you did implicitly mention price.

With a moniker like "kafkaesq" you must be really smart, so maybe you skipped over that part of my original comment. Or maybe it's just easier to be condescending than address the substance of a comment in your reply.

Yeah, I tend to skip the last 20% of post when the first 80% doesn't seem to address the main point of what it's responding to. Like a lot of bleary-eyed people here. Which is why I try to make a habit of getting to the most important part of what I'm responding to first, and deal with secondary or tertiary parts after that. But that's just me.

That said I didn't mean to be condescending, and apologize for it ending up that way.

As to what you were originally saying: I'm not sure your argument will "fly", as it were -- for the simple reason what most strongly predicts the carbon impact of a means of transport is not transit time but, generally, the amount of energy expended to get from A to B (not the transit time). And even though the flight may be shorter, something tells me the energy expenditure has to be much higher for supersonic than for subsonic flight -- in part precisely it needs to get to a much higher speed (i.e. get there with "decreased flight time") and attain a higher altitude before coming down again.

Reply on news.ycombinator.com