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submitted 1 day ago by Nakoichi@hexbear.net to c/news@hexbear.net

BUILD TRAINS I AM BEGGING YOU

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[-] Awoo@hexbear.net 45 points 1 day ago* (last edited 1 day ago)

Drawing attention to the rich by making them annoy people on a daily basis is the kind of failing empire shit you'd expect. Every single time you hear one of these among other people is a moment to use to agitate.

[-] MarmiteLover123@hexbear.net 19 points 1 day ago* (last edited 1 day ago)

The point is that there won't be any audible "sonic boom" anymore, and afterburning engines won't be used, so the engine sound and fuel consumption will be less of an issue. Boom technologies flew a technology demonstrator, the XB-1, at supersonic speeds earlier this year without a sonic boom being audible at ground level. The aircraft flies at high altitude at low supersonic speeds (Mach 1.1-1.3 for the XB-1) and the sound waves from the sonic boom get diffracted back towards the horizontal by the warmer thicker air at lower altitudes, so there is no audible sonic boom at ground level. The phenomenon is called Mach cutoff. Flying at supersonic speeds without the use of afterburner to cruise or accelerate to supersonic speeds is called supercruise. The plan™ is to scale this technology up for larger aircraft, such as 50-100 seater passenger aircraft like the Boom Overture concept (does not exist yet outside of CGI rendering). Even low supersonic speeds would decrease in flight time significantly. Cruising at Mach 1.35 is 50% faster than cruising at Mach 0.9 for example.

Is this realistic and commercially viable? I don't know, it seems very expensive for a few luxury fast flights. But the technology is there, as long as the financial backing is there (the biggest obstacle to viability), it's technically possible. Supercuise and Mach cutoff solve two of the biggest issues commercial supersonic flight had previously with the Concorde. Comac in China wants to do something similar in the future. The question then becomes how much people are prepared to pay for 50% shorter flights, and how much the cost of supersonic flight has been reduced by improved technology.

[-] dat_math@hexbear.net 7 points 1 day ago

The question then becomes how much people are prepared to pay for 50% shorter flights, and how much the cost of supersonic flight has been reduced by improved technology.

My main questions center on how much extra fuel is required to provide all that additional energy? Idk enough about fluid mechanics to answer this on my own: how much more energy does it take to accelerate from mach 1.1 to mach 1.2 vs mach 0.9 to mach 1.1?

[-] plinky@hexbear.net 5 points 1 day ago* (last edited 1 day ago)

it's not acceleration, it's air friction vs plane geometry, supersonic airflow has different optimal characteristics both for engines and flight surfaces/wings (naive kinetic energy is just differences of speed squared though).

But performing the Mach-cutoff flight “burns more fuel on the same distance than both subsonic and supersonic flight”, says Liebhardt. That makes it less economically viable than a regular supersonic flight and “the worst speed to fly at for fuel economy”. He sees Mach-cutoff flights as being more of a niche use case for “supersonic business jet users”, rather than for commercial airlines.

from new scientist

seems like they get shit of both worlds tbh with fuel economy (not zoomy enough to just cross distance fast with godawful fuel consumption/not optimized enough for flight at those speeds via engine regimes/geometry (that part might be fixable, but depends on how long it spends on subsonic climb/descend part of journey)

[-] dat_math@hexbear.net 4 points 1 day ago

oh that makes so much sense thank you!

[-] Diva@hexbear.net 57 points 1 day ago

If I have to listen to sonic booms every fucking day I am going to lose it jokah

[-] MaoTheLawn@hexbear.net 32 points 1 day ago

the perfect heartbeat to a dystopia

[-] SamotsvetyVIA@hexbear.net 22 points 1 day ago

they decided to bring the lebanese experience to america

[-] SpiderFarmer@hexbear.net 11 points 1 day ago

I can't even stand how common boosted subwoofers have become in cars over the past 10 years. Makes me want to hide in the woods.

[-] Le_Wokisme@hexbear.net 8 points 1 day ago

your comment could have been made any time in the last 3 decades

[-] SpiderFarmer@hexbear.net 5 points 1 day ago

Has it been exponential or something? Because my walls shaking feels much more regular now.

[-] uSSRI@hexbear.net 8 points 1 day ago

I thought it was worse 10-15 years ago, personally

[-] Le_Wokisme@hexbear.net 4 points 1 day ago

the fad started late 80s/early 90s shrug-outta-hecks

[-] SpiderFarmer@hexbear.net 4 points 1 day ago

It started then, but it's really seemed to go from a rarity to a constant.

[-] LaGG_3@hexbear.net 9 points 1 day ago

Some fighters flew overhead when I was at the grocery store ages ago (I think it was some escort for the president of amerikkka) and it sounded like a bomb went off or something

[-] dat_math@hexbear.net 7 points 1 day ago* (last edited 1 day ago)

A few years ago I was hiking in the middle of fucking nowhere, Utah, just enjoying the red rocks and seclusion, when an F18 rocketed directly above the slot canyon I was meandering through, banking hard to follow the general direction of the canyon and utterly frying my tympanic membranes for the next few tens of minutes.

I'm sure the military hardware fetishists would say I missed an opportunity for some kind of iconic photo of a fighter jet zooming through a frame of sandstone but all I could think about was how hard my ears were ringing and how disruptive that bullshit must be to literally all hearing wildlife.

I was maybe 100 feet below the top of the canyon and the jet couldn't have been more than 500 feet above that.

This is all to say that if commercial aviation starts getting loud in places where I try to enjoy the nature I too will likely lose it

[-] Evilsandwichman@hexbear.net 48 points 1 day ago

BUILD TRAINS I AM BEGGING YOU

Unfortunately Trump is......trainsphobic janet-wink

[-] Pentacat@hexbear.net 6 points 1 day ago

We need a trains megathread.

[-] tripartitegraph@hexbear.net 18 points 1 day ago

Even just hearing the air brakes from semi-trucks on the interstate, a mere 300 feet from where I live, drives me nuts. Hearing sonic booms with any regularity would tip me over the edge

[-] GoodGuyWithACat@hexbear.net 29 points 1 day ago

I want to hear the opinion of a commercial airline pilot who got very good grades.

[-] Jew@hexbear.net 9 points 1 day ago

Yea, what does Nathan Fielder think about this?

[-] Florn@hexbear.net 21 points 1 day ago

I wonder how this will interact with the multiple red states banning contrails

[-] InevitableSwing@hexbear.net 13 points 1 day ago

multiple red states banning contrails

Is that a ~15 year-old Onion bit made real?

[-] Calmrade@hexbear.net 5 points 1 day ago

I think that's how they've been getting most of the plotline lately.

[-] InevitableSwing@hexbear.net 3 points 1 day ago

plotline

I hope the beings that control our reality aren't like Hollywood execs. If they are - this week will surely feature death and mayhem.

[-] Calmrade@hexbear.net 2 points 1 day ago

We live in a capitalist hellscape, it always does.

[-] john_brown@hexbear.net 14 points 1 day ago

depends on if they fly within range of the anti-contrail patriot batteries

[-] Azarova@hexbear.net 21 points 1 day ago* (last edited 1 day ago)

Even if this goes through, it would take many years for anyone to develop a supersonic passenger jet because no one has been working on a design for one because no one has seriously floated the idea of lifting the ban. I doubt they're even worth it to the airline companies, since they're now essentially banks first and foremost, thanks to them all cashing in on having their own credit cards, who just happen to have airliners.

[-] miz@hexbear.net 15 points 1 day ago
[-] GaryLeChat@lemmygrad.ml 5 points 1 day ago

I can see it already, "Only big strong American jets are allowed to be supersonic, nobody else"

[-] quarrk@hexbear.net 14 points 1 day ago

NASA has been working with Lockheed Martin on the X-59 aircraft for several years, but we are still decades away from civilian supersonic flight.

[-] ArsonButCute@lemmy.dbzer0.com 11 points 1 day ago

While they're not efficient enough fuel-wise that an airline would pick them up, Concord jets do exist.

[-] plinky@hexbear.net 20 points 1 day ago

yeah, but fuel economy doesn't make sense even for transatlantic porkies.

although local porkies getting gulfstream supersonic edition would be funny

Boeing 737 Max Supersonic

[-] iridaniotter@hexbear.net 6 points 1 day ago* (last edited 1 day ago)

The old ban was for flight faster than Mach 1, yet was ostensibly put in place due to outcry over sonic booms. Well, if it's sonic booms that people care about, that is an issue of (loud) shock waves. The executive order instead asks for an interim regulation based on noise, the actual part of sonic booms that people take issue with and which is actually fixable. So, it's good!

The other issue is the energetics of supersonic flight. It takes more fuel, and thus pollutes and costs more, and is thus also for the rich only. All true. The only way to address the environmental factor is to bring down the cost of synthetic aviation fuel by greatly increasing green energy production. By the time a supersonic airliner is ready to fly in a couple decades, China will probably be able to do this assuming the administration(s) in Northern America are willing to import.

[-] terminhell@lemmy.dbzer0.com 2 points 22 hours ago

If they go mach+ only at altitude, don't think it'll be a problem. Back in the 90's as a kid I lived near a military bombing range in southern California. Jets would often be flying supersonic. It shook the walls just as much as the actual bombs sometimes. But they were already flying fairly low on approach to the range. It was hard to tell what was a sonic boom, explosions, or an earth quake sometimes XD. Then you'd have whole formations with apache helicopters and the cargo/fortress bombers with jets....

All that said, as long as they're only allowed to go supersonic at higher altitudes it shouldn't be an issue.

[-] iridaniotter@hexbear.net 2 points 20 hours ago* (last edited 20 hours ago)

There has also been work done on supersonic planes that produce shockwaves that make much less noise.

[-] altphoto@lemmy.today 12 points 1 day ago

Brought to you by windows 11... You'll need many more windows now!

[-] iridaniotter@hexbear.net 2 points 1 day ago* (last edited 1 day ago)

Can you post the article text? It's paywalled and the archives don't have the full version.

[-] Nakoichi@hexbear.net 3 points 1 day ago

Weird it wasn't paywalled for me. At work rn tho.

[-] Hawk@lemmy.dbzer0.com 2 points 1 day ago

After stumbling to get on a plain, is he going to ban stairs to a plane?

this post was submitted on 09 Jun 2025
88 points (100.0% liked)

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