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The faster the plane goes, the more fuel it consumes due to the drag increase by the square of the speed. In a world where fossil fuel is needed to fly airplane
by AlphaCharlie 3y ago
The faster the plane goes, the more fuel it consumes due to the drag increase by the square of the speed. In a world where fossil fuel is needed to fly airplanes and where oil is causing a destruction of the world we inhabit, it's dangerous to suggest we should make the flying industry polluting more than they already are.
If anything we should look at the trade-off benefits of flying with the least amount of fuel consumption per passenger and miles flown. Flying faster than mach-1 to save time will be reserved to a small elite. How does it benefit the masses?
- tormeh 3y ago> The faster the plane goes, the more fuel it consumes due to the drag increase by the square of the speed This is not actually true. Drag is at max at around mach 1. After that it goes down again. If you go fast enough you can be very efficient.
- avereveard 3y agoDrag goes back from the transonic peak but not below what was at subsonic speed. The gain comes from being able to fly in thinner air if the plan be is designed to survive the the transonic regime and supercuise, because mach speed becomes lower higher you fly and the air thinner, so lift available to subsonic planes is limited
- raincole 3y agoMaybe it should be replaced with a fuel-per-mile limit?
- panick21_ 3y ago> The faster the plane goes, the more fuel it consumes due to the drag increase by the square of the speed. ... at the same altitude.
- deleted 3y ago[deleted]
- crazygringo 3y agoOh interesting. Looking it up, the Concorde flew at 60,000 ft, compared to normal planes at 30,000 ft. And atmospheric pressure at 60k ft is less than a quarter of what it is at 30k. Is it possible to fly twice the speed of a regular aircraft but without using that much more fuel, by flying higher? Or does the plane have to burn even more fuel to get up to that altitude and maintain lift in a thinner atmosphere?
- bombcar 3y agoThere’s a balance. And the Concorde had to have weird stuff to get that high but yes - you can get better performance higher to a point.
- gallexme 3y agoNot twice as much I think, but it's definitly more efficent to fly higher if it's in the efficent envelope of these engines , just alone cause winds up there are way way faster which can be very favorable, because of the Coriolis Effect
- zamnos 3y agoDoesn't that also imply that it would be possible to fly a modified plane at the regular speed of a regular aircraft at that much higher altitude, and use way less fuel? Airlines' main cost driver is fuel, so it seems like they'd take advantage of that as much as possible.
- barelysapient 3y agoI think that would require a different plane design since they'd have less lift at that altitude.
- davidw 3y agoSeems like a good job for a carbon tax to change the economic calculations involved. Perhaps for some, the speed would be worth it, but they'd be paying for it.
- verandaguy 3y agoI strongly agree with your point, but I think some extra context is warranted. As it stands, the economics of air travel force carriers to optimise for reducing fuel consumption, since that's (by far) the biggest fraction of a commercial aircraft's operating cost. If supersonic transport makes a comeback, it'll be because the economics will make sense, which (in my mind) will be either because of: - Somehow reduced fuel consumption, potentially through engines that leverage the effects of the supersonic flight regime for increased fuel efficiency (e.g. ramjets, through that likely wouldn't be possible in low-supersonic flight) -> As another commenter in this thread mentioned, drag decreases with lower atmospheric pressure at higher altitudes, so there are fuel efficiency gains to be made just by flying higher, within the engines' design constraints. - It'll fill the niche of richer-than-god people who use jets to skip highway traffic. There's likely more cases than just these, but these are just the greatest hits as far as I can tell; and I say all of that as someone who's not involved in the aviation industry. For the record, I don't support this second niche existing, but it does, and it can be an economic driver.
- AlphaCharlie 3y agoThat's a very eloquent way to put it, I agree to it all :)
- CyanBird 3y agoThe second niche as a rule of thumb pollutes-more-than-God already(0) I am skeptical that lifting barriers to them polluting more would land any type of net benefit given that ultra-luxury products such as said jets don't tend to land outsized downstream advancements than let's say, funding basic sciences such as what Boeing or Airbus are already doing (0) https://www.oxfam.org/en/press-releases/billionaire-emits-million-times-more-greenhouse-gases-average-person https://www.oxfam.org/en/press-releases/billionaire-emits-mi... If it could be proved that things like faster private jets or faster planes could benefit in a sizeable and proportionate way to the general public, then yeah I would be in favor of this too, but as it stands I don't find the available info compelling, I'd rather them to pay more taxes
- verandaguy 3y ago
- goodluckchuck 3y ago[flagged]
- arcticbull 3y ago> Bold claims such as man made climate change require bold evidence. Boy is it a good thing we have it then.
- goodluckchuck 3y agoWould you mind sharing it?
- AlphaCharlie 3y agoI'm going to assume you are not trolling and hope this will change your mind, but I am not sure what proof you expect will convince you. It's worth asking yourself before reading these what is the level of proof you require to be convinced, and then see if these are fulfilling your expectations. - from CalTech: https://scienceexchange.caltech.edu/topics/sustainability/evidence-climate-change https://scienceexchange.caltech.edu/topics/sustainability/ev... - from NASA: https://climate.nasa.gov/evidence/ https://climate.nasa.gov/evidence/ - from Cornell: https://news.cornell.edu/stories/2021/10/more-999-studies-agree-humans-caused-climate-change https://news.cornell.edu/stories/2021/10/more-999-studies-ag... - from Columbia: https://news.climate.columbia.edu/2017/04/04/how-we-know-climate-change-is-not-natural/ https://news.climate.columbia.edu/2017/04/04/how-we-know-cli... - See statements from scientific organizations across the world (in case you the leading schools of the USA aren't convincing you): https://en.wikipedia.org/wiki/Scientific_consensus_on_climate_change#Statements_by_scientific_organizations_of_national_or_international_standing https://en.wikipedia.org/wiki/Scientific_consensus_on_climat... - scientific journal: https://phys.org/news/2017-11-man-made-climate-proven.html https://phys.org/news/2017-11-man-made-climate-proven.html - united nations: https://www.un.org/en/un-chronicle/climate-change-disasters-and-their-mitigation https://www.un.org/en/un-chronicle/climate-change-disasters-... I have not read this one in depth but maybe it will help change your mind on some misconceptions: https://skepticalscience.com/ https://skepticalscience.com/ I'm happy to link similar studies from across the world if you speak other languages. I know for every link I send you, you will find an equal number of links from climate change deniers. Put please put in perspective the number of people on one side of this issue and the other: the overwhelming majority of scientists agree. And even if they are wrong, is it really that bad to try to burn less oil and make the air less polluted and our planet more hospitable?
- looping__lui 3y agoFunnily enough the SR71 at Mach 3.5 had a better mpg than a Boeing 747 below Mach 1. It’s kind of hard to compare apples to apples here - but at supersonic speed, different engine technology can be used with better fuel efficiency…
- gleglegle 3y agoPer passenger?
- deleted 3y ago[deleted]
- Retric 3y agoNo.
- lfowles 3y agoIt also only carried 2...
- taeric 3y agoYou also have to compare getting to that speed. And, of course, the comparison is dead when done per passenger. Might as well compare a missile in there, or a drone.
- SkyMarshal 3y agoProbably also because it flew much higher with less air density and drag.
- AlphaCharlie 3y agoThe SR71 was flying at a much higher altitude to achieve lower drag and fits 2 pilots, 0 commercial passengers. If you want to compare apples to apples, I suggest you refer to the 2 metrics I mentioned: - gallons of fuel per miles flown - fuel used per passenger One without the other is a useless comparison as you pointed out.
- 3y ago
- snapplebobapple 3y agoThis is a terrible argument because it presumes there are no uses of faster travel that are beneficial. The proper argument is for a carbon tax that captures the externalities caused by emitting carbon and then to let individuals decide if they want to pay that or not for whatever activity they are partaking in. Whether it benefits the masses or the elite is irrelevant, what is relevant is that the use is worth more than the correctly priced cost of carbon
- pydry 3y ago>The proper argument is for a carbon tax The proper argument is to get a carbon tax first before unbanning anything like this. And it's not on the political horizon so....
- denton-scratch 3y agoCarbon taxes (as they exist now) are a con. You just buy some carbon credits from some company that is supposedly carbon-negative, because it plants forests somewhere so obscure that nobody checks. And anyway, forests are not carbon-negative; all that lives must die. They're carbon-neutral.
- ianburrell 3y agoCarbon tax != carbon credits. Carbon credits are part of emission trading approach. Carbon tax doesn't need credits cause uses money. Not being cheatable is one of the advantages of carbon tax.
- nwallin 3y agoWe do not have carbon taxes, we have carbon credits. Carbon credits are at best green political theater. At worst they're an effective means for the carbon economy (coal, oil, gas) to deflect efforts to get a carbon tax on the table, as evidenced by comments like this one. Carbon taxes, on the other hand, are an effective solution to global warming.
- aziaziazi 3y ago
- seventytwo 3y agoIf we had a robust carbon pollution tax, then this wouldn’t be a problem. The emissions would be priced into the ticket, and we could all (theoretically) fly easy. The root of all this is really just that the pollution from fossil fuels needs to be paid for.
- bendbro 3y ago[flagged]
- TylerE 3y agoYou can get around that by flying higher, where the air is thinner. This is easier if you faster.
- dan-robertson 3y agoThis seems like a pretty bad reason to want speed limits, because the thing you actually want to limit is fuel inefficiency. I think rules should normally try to achieve their goals through first-order effects rather than second order effects. I don’t think wanting fuel efficiency is incompatible with getting rid of the speed limit rule.
- idiotsecant 3y agoSometimes behaviour is legislated through second order behaviours because legislating first order behaviour is politically sensitive, or sometimes because even though the primary behaviour is already legislated the second order behaviour is as well. Not saying it's right, but it's exceedingly common. I'd make an example but these are exactly the sort of things that launch off topic 10 page discussions with very low information content.
- dan-robertson 3y agoSure, there are exceptions. When I wrote ‘normally’ to cover them, I was more thinking of things where it is hard to set good metrics for the thing one wants controlled, or cases where avoiding the spirit of the rule would be too likely. Nevertheless, I think those are exceptions. I think first order effects tend to matter more than second order effects (that’s why they’re called first order) and not doing good first-order things because of potentially bad second-order things is often wrong.
- slowmovintarget 3y agoAnd sometimes the legislation is the way it is because the legislature works from an understanding that is easy to popularize... and wrong.
- mgbmtl 3y agoI would be a bit skeptical, considering how many car makers tried to trick the measurement of emissions. Create a metric, people will game it.
- 3y ago
- r2b2 3y agoWhy mix regulation of two effects (sound and emissions)? It's smarter to write regulation for each uniquely and directly. Eg. - Sound from air traffic shall meet <sound regulations> and when violated will incur automatic fees of <formula> amount. - Air traffic emissions are required to meet <emission regulations> and will be taxed at <formula> amount (which should be used to offset pollution).
- msm_ 3y agoI agree with you in principle, but it's probably easier to enforce speed limits than sound and emissions (because both are hard to measure while in air, in contrast to speed).
- capableweb 3y agoSound would be measured at the ground, I presume, as no one is really bothered by loud things up in the sky, but by the ground. For emission, require airlines/airplanes to have a emission-sensor installed that automatically measure the emission. As a part of take off, make it mandatory to check it's working and as a part of landing, make sure it sent there data to where it has to go.
- cat_plus_plus 3y agoYou know you can just tax fuel according to amount of carbon right?
- c0balt 3y ago“If the penalty for a crime is a fine, then that law only exists for the lower class”
- cdogl 3y agoBe careful witn that reductive reasoning. Fines are an entirely reasonable mechanism to regulate an industry that is highly competitive with tight margins.
- 3y ago
- bilsbie 3y agoBut we still need an exception for billionaires and climate activists to travel to climate change summits.
- ndr 3y agoIf you care about emissions then limit emissions. Limiting proxy metrics, almost as speed instead of noise, when the limit is pretty easy to enforce doesn't do anything other than stifling innovation.
- oceanplexian 3y agoI’m a pilot and this is… a vast oversimplification. Jet aircraft are significantly more efficient at higher speeds and at higher altitudes precisely because there’s less drag up there and the engines can operate more efficiently. They are wildly inefficient when low and slow. A lot of the assumptions people make about efficiency don’t hold water in aerospace. There are no laws of physics preventing supersonic aircraft from being efficient provided they can fly high enough and we figure out how to build better engines.
- sillysaurusx 3y agoI don’t think people will believe you even though you’re right. Pure math has a strange way of swaying one’s opinions; ML in particular suffers from this. But thank you for trying to point out that engineering efficiencies matter a great deal. Hopefully the message will get through.
- witheld 3y agoI thought you were saying that Marxism-Leninism suffers from naivety of pure math and I was really twisting my brain working that one out
- sillysaurusx 3y agoEconomic theory isn’t free from this phenomenon either. :) Though I wonder if it’s possible to model the probability of a communist revolution.
- ithkuil 3y agoAh finally I understand why everybody is so worked up about Anarchist Ideology lately
- ramraj07 3y agoPlease unsimplify this then? Can you give a scenario where flying faster would be more economical fuel-wise?
- deleted 3y ago[deleted]
- camel_gopher 3y ago“ n order to slow the rate of the damage, the Federation Council shared the findings with all known warp-capable species and imposed a speed restriction of warp factor 5 on all Federation vessels in all but extreme emergencies. The areas of space most damaged by that point were restricted to essential travel only.”
- paulcole 3y agoEverybody sure can find something to handwring over when it comes to climate change. We fucked the environment pretty good and we’ve barely begun to feel the effects. Let’s just fly around really fast and enjoy it for the next century or os.
- eru 3y ago> The faster the plane goes, the more fuel it consumes due to the drag increase by the square of the speed. In a world where fossil fuel is needed to fly airplanes and where oil is causing a destruction of the world we inhabit, it's dangerous to suggest we should make the flying industry polluting more than they already are. Just tax fuel to price in the externality and let people decide how much they want to spend? > Flying faster than mach-1 to save time will be reserved to a small elite. How does it benefit the masses? The elite are also people.
- geysersam 3y agoWe're soo far from this though. Air fuel is taxed very little due to the Chicago convention. How much should it be taxed to factor in the external cost?
- eru 3y ago> How much should it be taxed to factor in the external cost? I don't know. But that can be treated as a technical problem to figure out. (Problems being technical is good! Much more tractable than political or social problems.) > Air fuel is taxed very little due to the Chicago convention. I'm not quite sure how much the Chicago convention would hinder a clever law drafter. Judging by what I can see at Wikipedia on it, I would imagine you could technically tax not kerosene itself, but the burning of kerosene inside your airspace.
- cat_plus_plus 3y agoYou are again trying to control the wrong thing - speed vs noise or carbon emissions. Price carbon and let details sort themselves out. Also by the same token, small elite will not generate a lot of carbon in the big picture.
- dieselgate 3y agoif we’re talking passenger miles per gallon then commercial planes are often more efficient than vehicular transport, especially when considering vehicles with only 1 or 2 passengers
- aaron695 3y ago[dead]