Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Supersonic flight returning to US after half-century ban

forbes.com

Post reply on HN
Print view View original

171–180 of 207 posts

Re: Supersonic flight returning to US after half-century ban

#171

Post by throwaway2037 »

HlessClaudesman wrote: post #58
foobarqux wrote: post #51

Earlier quoted context omitted.

There is a substantial noise beyond the initial boom which is very loud even relative to the main boom. But even just a half second of a car horn going off right next to you every so often is intolerable.

People finding a way to tolerate what was previously considered intolerable is pretty much the story of civilization.

I disagree. The more that I travel, the more that I notice the trend: The richer you become, the quieter you become. Even in the same country, income level seems to strongly correlate with how loud you are in public (and private).

Re: Supersonic flight returning to US after half-century ban

#172

Post by throwaway2037 »

fragmede wrote: post #163
michaelmrose wrote: post #144

Earlier quoted context omitted.

Its not clear why you would think any of this works this way. Not one thing you said makes sense it's like a weird trickle down economics for flights as if better steaks would get oliver twist more gruel

Food is different from airplanes. On a middle class salary, I could afford to take a flight from Atlanta to Liberia and back for $300. Or $250 to get to Vegas and back. Spirit recently went out of business, but in 100 years I bet supersonic jet travel will be available to the middle class.

Liberia the African country or Liberia the city in Costa Rica?

Re: Supersonic flight returning to US after half-century ban

#173

Post by throwaway85825 »

fragmede wrote: post #164
throwaway85825 wrote: post #131

Earlier quoted context omitted.

Physics doesnt change. It will always cost more energy to fly faster.

Relatively, absolutely, but look at computers. Yes, more computing still costs more than less computing. Physics hasn't changed, but the cost of computers has. I have, in my hand, for part of a couple months of middle class wages, more computing power than existed in the world in 1960.

Yes and now wafer costs are going up for n+1 node, because of physics reasons.

Re: Supersonic flight returning to US after half-century ban

#174

Post by LoganDark »

asdfadsfgfdda wrote: post #81
foobarqux wrote: post #49

Earlier quoted context omitted.

> It’s not accurate to convert .1 psf to dB because it’s an impulsive shape, not a continuous tone. And human loudness perception depends on how smooth (low frequency) the shape is Sorry can you explain more? It's just the definition of dB (?) And it's less impulsive than you imagine, go to youtube to listen to the sonic boom + continuous roar. The FAA has no criteria about the "texture" of the sound and there is no…

On a typical day, the atmospheric pressure varies by maybe 150 Pa, or 3 psf. By definition, that’s 137 dB. But it’s imperceptible because the rate of change is so low.

A sonic boom doesn't exactly average out over the length of the day, though, does it?

Re: Supersonic flight returning to US after half-century ban

#175

Post by throwaway85825 »

randallsquared wrote: post #162
throwaway85825 wrote: post #161

Earlier quoted context omitted.

That's only possible under specific climatic conditions where there's separate temperature/pressure layers. Which is why they asked to repeal the ban on supersonic flight over populated areas. If they actually thought it wouldn't make noise they wouldn't be asking for the rule to be changed.

The rule bans the supersonic flight regardless of whether it's audible or not, so they'd still be asking for the rule to be changed.

They didn't ask for only a non audible change, because they know that it will not be. It's just marketing and misdirection because the truth is much less rosy.

Re: Supersonic flight returning to US after half-century ban

#177

Post by InsideOutSanta »

WalterBright wrote: post #114
foobarqux wrote: post #8

0.11 pound per square foot is what is being proposed. That's 108 decibels. Which is between standing next to a lawn mower and standing next to a car horn. I don't see how anyone will tolerate that in practice. https://www.omnicalculator.com/physics/db

Back in the 1960s (!) the military would fly supersonic over the town I lived in. I always enjoyed the boom. I would also open the window during a thunderstorm or go sit on the porch because I enjoyed the incredible electric display and the booms.

Yeah, I often have military flight training over my town, and I don't find the sonic booms particularly bad. I barely notice the planes unless they fly close to the ground over my house.

I'm not sure how the sonic booms of fighter jets compare to passenger planes, though.

Re: Supersonic flight returning to US after half-century ban

#178

Post by pkulak »

arjie wrote: post #41

This is so exciting. The only ones I know working on this are Boom (unless they’ve pivoted entirely into AI DC turbines). Between this and the wind-turbine-blade air transporter it’s an exciting time for aviation. Now if we can only transition off leaded fuel!

> This is so exciting.

How exactly? Purely on a tech basis? Because it's not solving a real problem anyone has. Some millionaire who wants to go from NYC to LA a couple hours faster is not a problem worth solving. And certainly not when it's less efficient, and inconveniences everyone in the flight path with a very loud noise.

Re: Supersonic flight returning to US after half-century ban

#179

Post by pkulak »

InsideOutSanta wrote: post #177
WalterBright wrote: post #114

Earlier quoted context omitted.

Back in the 1960s (!) the military would fly supersonic over the town I lived in. I always enjoyed the boom. I would also open the window during a thunderstorm or go sit on the porch because I enjoyed the incredible electric display and the booms.

Yeah, I often have military flight training over my town, and I don't find the sonic booms particularly bad. I barely notice the planes unless they fly close to the ground over my house. I'm not sure how the sonic booms of fighter jets compare to passenger planes, though.

I can't stand military jets over my neighborhood. I get irrationally angry every time I'm walking somewhere with my wife and we both have to completely stop talking for two blocks because some F-14 is blasting around over our heads. They are just unbelievably loud.
Post reply on HN