4 ms·

No-boom supersonic flights could slide through US skies soon

34 points by rntn 1y ago

7e 1y ago
The emissions of supersonic aircraft are insane. They’re just so inefficient. Nobody needs to fly anywhere that fast when they can sleep on a lie flat bed in business class instead. Let’s stop polluting the earth and put that money into battery and hydrogen aircraft instead.
- api 1y ago
  Fuel is the #1 cost of airlines, so this will be niche unless the efficiency problem is solved. As for climate change and oil use, all aviation globally is only about 7% of oil use and about 3% of carbon emissions. It’s not the main thing to worry about. Coal fired electricity followed by oil fired land transport (mostly easily electrified cars) are together well over 50% of all emissions and are the easiest things to fix. Deforestation and agricultural emissions are also up there. All of these sources are way easier and cheaper to address than decarbonizing aviation.
  - paulryanrogers 1y ago
    We can worry about more than one thing at a time
    - api 1y ago
      It makes the most sense to tackle the easiest biggest wins first. There is limited attention, money, and political capital. Aviation is perhaps the hardest single thing to decarbonize.
      - paulryanrogers 1y ago
        And the biggest consumers of air passenger travel are the rich. They can be incentized to fly less with the stroke of a pen: tax usage. I'm sure the world will keep spinning despite them having only one of two trips to their private island each year. Thankfully we don't have to stop at one thing. Or even limit ourselves to doing one thing at a time.
        api 1y ago
        If you want to argue against inequality, make that argument on its own merit without hijacking climate change and using it as a stalking horse. Climate change is its own problem. Physics doesn’t care what our gini coefficient is. A more equal society that emits too much carbon still has this problem. A decarbonized society powered by renewable and nuclear energy could still have too much inequality.
        paulryanrogers 1y ago
        Until democracy is fixed I don't think these problems can be disconnected. But I'll admit that even an equal society could barrel toward its own destruction. I just think equal societies are less likely to, because all our livelihoods would be on the line. None could deny the problem and strong arm the government to ignore it--for the short term benefit of the few at the top.
        api 1y ago
        I think a more equal society would, if it were using fossil fuels, emit more carbon. A more equals society would have fewer people in poverty. It would have more active services for people who need them. All that represents a lower entropy state. Lower entropy states require more external energy input to maintain, not less. Allowing vast numbers of people to rot in squalor while a few rich people live it up is a lower energy higher entropy state. Individual rich people may use crazy amounts of energy but there are not many of them. Bezos’ jet consumes a tiny fraction of the power required to provide continuous modern health care to everyone, for example.
  - appreciatorBus 1y ago
    This assumes that decarbonizing aviation is the only way to address the issue. A much simpler one, that costs nothing, is simply if we did less aviation. If we had the political will, even just trying to get somewhere close to pricing pollution externalities of aviation (in addition to other pollution sources, to be clear), would immediately reduce demand and make other forms of transportation more competitive. Of course we don’t have that political will, so it may be true that the only choice is to come up with expensive and esoteric technologies to decarbonize aviation. But I think it’s important to acknowledge that flying less was always an option we (collectively) had, but chose not to take.
    - api 1y ago
      True, but why is it that so many people concerned about climate fixate on aviation? It’s 3% of world carbon emissions. It’s tiny, it’s pivotal to the economy, and it’s hard to change. It’s the worst thing to fixate on, the one you’ll make the least progress toward. What we should be fixating on is “end coal” because coal burning, largely for power generation, is both the largest single source and one of the easiest to replace. Yet that climate group is called “end oil” not “end coal.” Why? If we actually think climate change is a problem we need to think like scientists and engineers and prioritize rationally. We also have to be willing to put politics aside and make a broad and wide appeal, arguing that fixing this is in everyone’s long term interest (because it is).
      - appreciatorBus 1y ago
        I think part of the answer is that not everyone is convinced it's pivotal. Only a small amount of aviation is pivotal by any definition, and that portion isn't very price sensitive, so paying for externalities wouldn't make much difference to it. Even in the richest country in the world, only half of the population took even one plane trip in 2024, and the distribution among those who did, probably skews heavily toward a very small # of frequent fliers. Aviation is super useful, no doubt. But like many difficult political problems, the benefits are concentrated on those who fly the most, or who consume most of the products that typically fly, and the costs are spread among those who fly the least, or not at all. Anyway, I have never seen someone advocate to ignore coal in favour of focussing on aviation. But I have seen a lot of people advocate to ignore aviation in favour of focussing on anything but aviation. As others have said, we can do more than one thing. Some of us can focus on coal, others on aviation. I am just a message board pundit, not involved in coal or aviation, nor advocacy around climate change on either. I am just skeptical of approaches that privilege one pollution source over another. Maybe politics means it's the best we can do, but that's not a very satisfying answer to some of us.
- Robotbeat 1y ago
  The difference in efficiency between subsonic and supersonic is about 2, which is smaller than the difference between a high density seatIng arrangement and lie-flat density (a factor of 3, I think?). If you’re doing a lie-flat bed, you just eliminated the entire difference in emissions per passenger.
  - i80and 1y ago
    I realize this makes me very unusual and this is probably not a good business idea, but I'd be happy to fly pod-hostel style. I don't mind being stacked as long as I get to lie down.
    - genocidicbunny 1y ago
      Just don't forget your multipass.
    - closewith 1y ago
      Me too, but it will never happen due to evacuation issues.
- ghc 1y ago
  I think you're exhibiting a lack of imagination here. There's plenty of time sensitive items the Concorde was used to transport, like organs for transplants, or serum for snake bite victims. Since the retirement of the Concorde we've regrettably had to use fighter jets for some of these life-saving flights. Sure, rich people subsidized all of it to shave a few hours off their business flights, but given how much avgas Elon's jet uses, it is really more efficient if they half the people who would take a supersonic flight take small private jets instead?
  - echoangle 1y ago
    Maybe unpopular opinion but with the costs associated with flying around organs for transplants or serum for snake bites at supersonic speeds, you could save a lot more people in different situations.
  - geertj 1y ago
    > given how much avgas Elon's jet uses Jets don’t consume avgas.
    - ghc 1y ago
      TIL. I've only made a few business plane trips, but thinking back on it they were all turboprops.
      - jordanb 1y ago
        Turboprops also run on jet fuel. Only reciprocating engines use avgas.
        jcalvinowens 1y ago
        Jets will run on anything that burns, most turboprops are allowed to burn avgas in emergencies. Some officially allow 100+ hours of avgas operation between overhauls.
  - dghlsakjg 1y ago
- 01HNNWZ0MV43FF 1y ago
  They should tax emissions
losvedir 1y ago
Growing up I always thought a sonic boom was something that happened once when you broke the speed of sound. I now understand that's not the case, but still don't quite know what it is. I think a supersonic aircraft is constantly "dragging" a boom behind it. So when it passes overhead sometime later you'll hear a boom. Is that right? Does that mean you'll see a plane flying overhead, hear the normal drone associated with it, but at one particular moment here a distinctly louder but shorter noise? And is this a real thing that can be done? How do you make the sonic boom go away? As someone who lives where planes are flying overhead constantly, can it be used to make non-supersonic planes quieter, too?
- freeone3000 1y ago
  When a boat goes faster than water, it makes water waves. When a plane goes faster than air, it makes air-waves. When a plane goes faster than sound, it makes sound-waves. It’s lightning/thunder: you will be able to see the plane, and then after a bit, hear the boom. You won’t be able to hear other plane noise, all of the combined noise from turbulence and engines is forced back into the boom. It is shorter duration, yes, but MUCH louder: F-18s at 5000 feet can rattle windows on the ground! Usually not a good trade-off.
  - zigzag312 1y ago
    You're mixing apples and oranges. Air and water are matter, sound is not. Any sound-producing plane generates sound waves, not just a plane that goes faster than sound.
    - freeone3000 1y ago
      Sound is the vibration of matter. Waves do not move matter! Like, look at a leaf on a lake. The leaf moves up and down with the ripples, but does not move back and forth. The water isn’t moving, the wavefront is. Sonic booms are nothing more than a collapsed wavefront of that wavefront. The speed of sound, definitionally, is the maximal speed at which any physical wavefront can propagate through a medium. (We hear it in air as sound, but no wave can be propagated through the medium any faster than this. You cannot move air any faster than the speed of sound in air.) This causes all of the disturbances from the aircraft moving through the air to be compressed into a single, maximal wave that itself moves at the speed of sound, since it can’t move any faster. Thus the boom. (You can see a similar cool thing with Cherenkov radiation, where neutrons moving faster than light in water produce a bright blue glow — or, waves of light!)
tiahura 1y ago
Don’t cell phones, not to mention inflight wifi, make it a lot less necessary for a lot of potential customers?
- tiahura 1y ago
  Not to mention business travel still hasn’t pushed through pre-COVID levels.
kgwxd 1y ago
[flagged]
- deleted 1y ago
  [deleted]
bgwalter 1y ago
In an article full of marketing speak, NASA only promises a quieter sonic thump: https://www.nasa.gov/news-release/nasa-lockheed-martin-reveal-x-59-quiet-supersonic-aircraft/ https://www.nasa.gov/news-release/nasa-lockheed-martin-revea... "The X-59 is expected to fly at 1.4 times the speed of sound, or 925 mph. Its design, shaping and technologies will allow the aircraft to achieve these speeds while generating a quieter sonic thump." Further, if the atmospheric conditions aren't right, the cutely named "thump" will turn into a boom again. I suppose if Qatar gifts Trump the first golden supersonic private jet, it'll also pay fines for "thumps" exceeding the limits.
gwerbret 1y ago
> The Supersonic Aviation Modernization Act (SAMA) > Boom boasts a number of big-name VCs and tech luminaries as funders, including AI poster child Sam Altman This... can't be a coincidence. Can it?
hellisothers 1y ago
My immediate thought was of imminent domain destroying houses and running highways through poor neighborhoods. Curious to see which cities/areas you’re allowed to fly the “less noticeable” boom over.
- dctoedt 1y ago
  > imminent domain destroying houses and running highways through poor neighborhoods Nit: eminent not imminent.

34 points by rntn 1y ago

7e 1y ago

The emissions of supersonic aircraft are insane. They’re just so inefficient. Nobody needs to fly anywhere that fast when they can sleep on a lie flat bed in business class instead. Let’s stop polluting the earth and put that money into battery and hydrogen aircraft instead.

api 1y ago
Fuel is the #1 cost of airlines, so this will be niche unless the efficiency problem is solved. As for climate change and oil use, all aviation globally is only about 7% of oil use and about 3% of carbon emissions. It’s not the main thing to worry about. Coal fired electricity followed by oil fired land transport (mostly easily electrified cars) are together well over 50% of all emissions and are the easiest things to fix. Deforestation and agricultural emissions are also up there. All of these sources are way easier and cheaper to address than decarbonizing aviation.
- paulryanrogers 1y ago
  We can worry about more than one thing at a time
  - api 1y ago
    It makes the most sense to tackle the easiest biggest wins first. There is limited attention, money, and political capital. Aviation is perhaps the hardest single thing to decarbonize.
    - paulryanrogers 1y ago
      And the biggest consumers of air passenger travel are the rich. They can be incentized to fly less with the stroke of a pen: tax usage. I'm sure the world will keep spinning despite them having only one of two trips to their private island each year. Thankfully we don't have to stop at one thing. Or even limit ourselves to doing one thing at a time.
      - api 1y ago
        If you want to argue against inequality, make that argument on its own merit without hijacking climate change and using it as a stalking horse. Climate change is its own problem. Physics doesn’t care what our gini coefficient is. A more equal society that emits too much carbon still has this problem. A decarbonized society powered by renewable and nuclear energy could still have too much inequality.
        paulryanrogers 1y ago
        Until democracy is fixed I don't think these problems can be disconnected. But I'll admit that even an equal society could barrel toward its own destruction. I just think equal societies are less likely to, because all our livelihoods would be on the line. None could deny the problem and strong arm the government to ignore it--for the short term benefit of the few at the top.
        api 1y ago
        I think a more equal society would, if it were using fossil fuels, emit more carbon. A more equals society would have fewer people in poverty. It would have more active services for people who need them. All that represents a lower entropy state. Lower entropy states require more external energy input to maintain, not less. Allowing vast numbers of people to rot in squalor while a few rich people live it up is a lower energy higher entropy state. Individual rich people may use crazy amounts of energy but there are not many of them. Bezos’ jet consumes a tiny fraction of the power required to provide continuous modern health care to everyone, for example.
- appreciatorBus 1y ago
  This assumes that decarbonizing aviation is the only way to address the issue. A much simpler one, that costs nothing, is simply if we did less aviation. If we had the political will, even just trying to get somewhere close to pricing pollution externalities of aviation (in addition to other pollution sources, to be clear), would immediately reduce demand and make other forms of transportation more competitive. Of course we don’t have that political will, so it may be true that the only choice is to come up with expensive and esoteric technologies to decarbonize aviation. But I think it’s important to acknowledge that flying less was always an option we (collectively) had, but chose not to take.
  - api 1y ago
    True, but why is it that so many people concerned about climate fixate on aviation? It’s 3% of world carbon emissions. It’s tiny, it’s pivotal to the economy, and it’s hard to change. It’s the worst thing to fixate on, the one you’ll make the least progress toward. What we should be fixating on is “end coal” because coal burning, largely for power generation, is both the largest single source and one of the easiest to replace. Yet that climate group is called “end oil” not “end coal.” Why? If we actually think climate change is a problem we need to think like scientists and engineers and prioritize rationally. We also have to be willing to put politics aside and make a broad and wide appeal, arguing that fixing this is in everyone’s long term interest (because it is).
    - appreciatorBus 1y ago
      I think part of the answer is that not everyone is convinced it's pivotal. Only a small amount of aviation is pivotal by any definition, and that portion isn't very price sensitive, so paying for externalities wouldn't make much difference to it. Even in the richest country in the world, only half of the population took even one plane trip in 2024, and the distribution among those who did, probably skews heavily toward a very small # of frequent fliers. Aviation is super useful, no doubt. But like many difficult political problems, the benefits are concentrated on those who fly the most, or who consume most of the products that typically fly, and the costs are spread among those who fly the least, or not at all. Anyway, I have never seen someone advocate to ignore coal in favour of focussing on aviation. But I have seen a lot of people advocate to ignore aviation in favour of focussing on anything but aviation. As others have said, we can do more than one thing. Some of us can focus on coal, others on aviation. I am just a message board pundit, not involved in coal or aviation, nor advocacy around climate change on either. I am just skeptical of approaches that privilege one pollution source over another. Maybe politics means it's the best we can do, but that's not a very satisfying answer to some of us.
Robotbeat 1y ago
The difference in efficiency between subsonic and supersonic is about 2, which is smaller than the difference between a high density seatIng arrangement and lie-flat density (a factor of 3, I think?). If you’re doing a lie-flat bed, you just eliminated the entire difference in emissions per passenger.
- i80and 1y ago
  I realize this makes me very unusual and this is probably not a good business idea, but I'd be happy to fly pod-hostel style. I don't mind being stacked as long as I get to lie down.
  - genocidicbunny 1y ago
    Just don't forget your multipass.
  - closewith 1y ago
    Me too, but it will never happen due to evacuation issues.
ghc 1y ago
I think you're exhibiting a lack of imagination here. There's plenty of time sensitive items the Concorde was used to transport, like organs for transplants, or serum for snake bite victims. Since the retirement of the Concorde we've regrettably had to use fighter jets for some of these life-saving flights. Sure, rich people subsidized all of it to shave a few hours off their business flights, but given how much avgas Elon's jet uses, it is really more efficient if they half the people who would take a supersonic flight take small private jets instead?
- echoangle 1y ago
  Maybe unpopular opinion but with the costs associated with flying around organs for transplants or serum for snake bites at supersonic speeds, you could save a lot more people in different situations.
- geertj 1y ago
  > given how much avgas Elon's jet uses Jets don’t consume avgas.
  - ghc 1y ago
    TIL. I've only made a few business plane trips, but thinking back on it they were all turboprops.
    - jordanb 1y ago
      Turboprops also run on jet fuel. Only reciprocating engines use avgas.
      - jcalvinowens 1y ago
        Jets will run on anything that burns, most turboprops are allowed to burn avgas in emergencies. Some officially allow 100+ hours of avgas operation between overhauls.
- dghlsakjg 1y ago
01HNNWZ0MV43FF 1y ago
They should tax emissions

losvedir 1y ago

Growing up I always thought a sonic boom was something that happened once when you broke the speed of sound. I now understand that's not the case, but still don't quite know what it is. I think a supersonic aircraft is constantly "dragging" a boom behind it. So when it passes overhead sometime later you'll hear a boom. Is that right? Does that mean you'll see a plane flying overhead, hear the normal drone associated with it, but at one particular moment here a distinctly louder but shorter noise? And is this a real thing that can be done? How do you make the sonic boom go away? As someone who lives where planes are flying overhead constantly, can it be used to make non-supersonic planes quieter, too?

freeone3000 1y ago
When a boat goes faster than water, it makes water waves. When a plane goes faster than air, it makes air-waves. When a plane goes faster than sound, it makes sound-waves. It’s lightning/thunder: you will be able to see the plane, and then after a bit, hear the boom. You won’t be able to hear other plane noise, all of the combined noise from turbulence and engines is forced back into the boom. It is shorter duration, yes, but MUCH louder: F-18s at 5000 feet can rattle windows on the ground! Usually not a good trade-off.
- zigzag312 1y ago
  You're mixing apples and oranges. Air and water are matter, sound is not. Any sound-producing plane generates sound waves, not just a plane that goes faster than sound.
  - freeone3000 1y ago
    Sound is the vibration of matter. Waves do not move matter! Like, look at a leaf on a lake. The leaf moves up and down with the ripples, but does not move back and forth. The water isn’t moving, the wavefront is. Sonic booms are nothing more than a collapsed wavefront of that wavefront. The speed of sound, definitionally, is the maximal speed at which any physical wavefront can propagate through a medium. (We hear it in air as sound, but no wave can be propagated through the medium any faster than this. You cannot move air any faster than the speed of sound in air.) This causes all of the disturbances from the aircraft moving through the air to be compressed into a single, maximal wave that itself moves at the speed of sound, since it can’t move any faster. Thus the boom. (You can see a similar cool thing with Cherenkov radiation, where neutrons moving faster than light in water produce a bright blue glow — or, waves of light!)

tiahura 1y ago

Don’t cell phones, not to mention inflight wifi, make it a lot less necessary for a lot of potential customers?

tiahura 1y ago
Not to mention business travel still hasn’t pushed through pre-COVID levels.

kgwxd 1y ago

[flagged]

deleted 1y ago
[deleted]

bgwalter 1y ago

In an article full of marketing speak, NASA only promises a quieter sonic thump: https://www.nasa.gov/news-release/nasa-lockheed-martin-reveal-x-59-quiet-supersonic-aircraft/ https://www.nasa.gov/news-release/nasa-lockheed-martin-revea... "The X-59 is expected to fly at 1.4 times the speed of sound, or 925 mph. Its design, shaping and technologies will allow the aircraft to achieve these speeds while generating a quieter sonic thump." Further, if the atmospheric conditions aren't right, the cutely named "thump" will turn into a boom again. I suppose if Qatar gifts Trump the first golden supersonic private jet, it'll also pay fines for "thumps" exceeding the limits.

gwerbret 1y ago

> The Supersonic Aviation Modernization Act (SAMA) > Boom boasts a number of big-name VCs and tech luminaries as funders, including AI poster child Sam Altman This... can't be a coincidence. Can it?

hellisothers 1y ago

My immediate thought was of imminent domain destroying houses and running highways through poor neighborhoods. Curious to see which cities/areas you’re allowed to fly the “less noticeable” boom over.

dctoedt 1y ago
> imminent domain destroying houses and running highways through poor neighborhoods Nit: eminent not imminent.