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

Boom XB-1 First Supersonic Flight [video]

youtube.com

Post reply on HN
Print view View original

271–280 of 545 posts

Re: Boom XB-1 First Supersonic Flight [video]

#271

Post by kridsdale1 »

ghaff wrote: post #205
senordevnyc wrote: post #201

Earlier quoted context omitted.

I’ve been one of the skeptical commenters (under another username), not because I think it’s technically impossible, or because I hate innovation or bold bets, but because I don’t think the economics make sense, and their original timelines and cost estimates were off by an order of magnitude, at least. Aviation is littered with startups that burned through hundreds of millions over the course of a decade or two and…

Not that I care as much these days, but would I have liked routine Mach 2 flight that my company would have paid for when I was traveling a lot? Absolutely. But that wasn't in the cards. And the relatively fewer flights I take today for relatively longer trips in general, I mostly look at paying an extra $5K and think "I could do a lot more interesting things with that money than be more comfortable for some hours" (…

I guess the target market is those who feel about the opportunity cost of another $5,000 the way you and I do about another $5.00

Re: Boom XB-1 First Supersonic Flight [video]

#272

Post by scythe »

hnuser123456 wrote: post #31
kindatrue wrote: post #9

Earlier quoted context omitted.

Previously Boom's CEO said this: “That’s not travel, that’s like a thing you might hope to do once in a lifetime,” says Scholl, before adding, “Versus where we want to get, which is anywhere in the world in four hours for 100 bucks.”[1] Anywhere in the world in four hours for $100 USD really caught people's imagination and attention. I'm puzzled by how they will achieve this. [1] https://www.cnn.com/travel/article/bo…

Huh. The longest flights are around 10,000 miles. They usually cost over $1000. Fuel apparently accounts for about 25% of ticket price on long haul, so $250 in fuel normally. To do that in 4 hours is to travel 2,500 mph. Naively, traveling twice the speed requires 8x the power, so going over 4x the usual 550mph should mean over 64x more fuel burn, or $16,000 in fuel alone. Maybe a bit less since drag doesn't grow qui…

>Naively, traveling twice the speed requires 8x the power, so going over 4x the usual 550mph should mean over 64x more fuel burn

You've forgotten to cancel the denominator. If you use the drag relation of speed to power, you're multiplying by time, but the time is reduced by the speed. It would be more straightforward to use the F ~ v^2 relation between speed and force. So going 4x as fast for the same distance would require 16x the fuel, while going 4x as fast for the same time would require 64x the fuel. But the latter would obviously never happen in practice as you'd circumnavigate the Earth.

Re: Boom XB-1 First Supersonic Flight [video]

#273

Post by rsanek »

Retric wrote: post #269
ergocoder wrote: post #266

Earlier quoted context omitted.

Basically, the critics: "unless you build a 100B company, we are not wrong" I mean, yeah, sure.

It’s hard to argue a startup succeed until profits > investment.

if your only measure of success is monetary profit, then sure. i think that shouldn't be the only metric, and in fact, the focus on that so completely is a big part of the problem with what people term "late-stage capitalism"

Re: Boom XB-1 First Supersonic Flight [video]

#274

Post by papertokyo »

hinkley wrote: post #168
ctippett wrote: post #46

The plane looks so small on the runway, I thought how could it possibly hold 64-80 passengers. Hint: it's because the XB-1 is a one-third scale model of their fully fledged Overture.

So it’s a jet for ants?

Until they make it at least three times bigger, yes.

Re: Boom XB-1 First Supersonic Flight [video]

#275

Post by scythe »

hugs wrote: post #237

I haven't seen anyone directly address it in the comments here (or in the video): was an audible sonic boom noticeable on the ground during today's test flight?

Noticeable is certainly a way of putting it.

https://en.wikipedia.org/wiki/Oklahoma_City_sonic_boom_tests

>However, in the first 14 weeks, 147 windows in the city's two tallest buildings, the First National Bank and Liberty National Bank, were broken.

If a sonic boom is "noticeable", that's one thing. But the problem is that even from cruising altitude they're shockingly loud. If the sonic boom is merely bearable, that's quite an improvement.

Re: Boom XB-1 First Supersonic Flight [video]

#276

Post by kaonwarb »

OnlineGladiator wrote: post #249
pembrook wrote: post #228

Earlier quoted context omitted.

Endless pessimism, even in the face of evidence to the contrary is a hallmark of HN. Thank you for continuing the tradition. May you never hold out hope for anything positive in the future.

Blind optimism is just as obnoxious as blind pessimism - both are based on ignorance. Boom still hasn't solved the 2 hardest problems after nearly a decade. Currently regulations prohibit supersonic flight over land. It's a total guess whether or not they'll be able to overcome this, but I remain skeptical both of their noise claims and their ability to overturn legislation. Also they don't have a real plan for an en…

Disagree that blind optimism is just as obnoxious. Blind pessimists are much less likely to reach beyond what's currently considered possible. We need irrationally optimistic folks.

Re: Boom XB-1 First Supersonic Flight [video]

#277

Post by hugs »

scythe wrote: post #275
hugs wrote: post #237

I haven't seen anyone directly address it in the comments here (or in the video): was an audible sonic boom noticeable on the ground during today's test flight?

Noticeable is certainly a way of putting it. https://en.wikipedia.org/wiki/Oklahoma_City_sonic_boom_tests >However, in the first 14 weeks, 147 windows in the city's two tallest buildings, the First National Bank and Liberty National Bank, were broken. If a sonic boom is "noticeable", that's one thing. But the problem is that even from cruising altitude they're shockingly loud. If the sonic boom is merely bearable, th…

Right, and making an improvement is a big part of Boom's marketing. (It's in their name?!) I'm surprised I didn't hear them make any comments about it in the video during the flight as they crossed the sound barrier each time. Unless I missed it?

Re: Boom XB-1 First Supersonic Flight [video]

#278

Post by papertokyo »

IndrekR wrote: post #176
drysine wrote: post #109

Earlier quoted context omitted.

Won't do things like A380?

Without A380 there would be no A350 XWB.

Why is that? (These are my favourite planes to fly on, curious how the A350 is derivative given the apparent difference in packaging.)

Re: Boom XB-1 First Supersonic Flight [video]

#279

Post by Retric »

rsanek wrote: post #273
Retric wrote: post #269

Earlier quoted context omitted.

It’s hard to argue a startup succeed until profits > investment.

if your only measure of success is monetary profit, then sure. i think that shouldn't be the only metric, and in fact, the focus on that so completely is a big part of the problem with what people term "late-stage capitalism"

Start a social club/co-op/non-profit/religion or whatever and the metrics are different.

However, when you’re asking for investments your goal better be profit or you’ve just committed fraud.

Re: Boom XB-1 First Supersonic Flight [video]

#280

Post by ctippett »

chgs wrote: post #256
EA-3167 wrote: post #32

Earlier quoted context omitted.

There are some interesting technological developments around fuel efficiency and minimizing the "sonic boom" that's felt on the ground. Neither of those killed Concorde though, because the entire idea of Concorde turned out to be incredibly faulty. MOST people weren't in such a hurry to get from point A to point B that they'd pay 5x-10x a normal business/first class ticket to cut a trip down by 50% or so. The intende…

Last time I flew from Heathrow it was 45 minutes from car to take off, and that was with a 20 minute door close. It doesn’t take 2 hours to go through security , certainly not in the first class section in any case.

Ah yes, let's use the timeline for a first class passenger as the average for how long it takes to go from check-in to take off.
Post reply on HN