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One dead as London-Singapore flight hit by turbulence

bbc.com

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Re: One dead as London-Singapore flight hit by turbulence

#321

Post by et-al »

mayd wrote: post #285
et-al wrote: post #260

Earlier quoted context omitted.

One is an island nation that's been fairly open, the other had waves of isolationism, famines, and only recently opened up their markets in the late 80s. Private car ownership was not on the table until probably 25 years ago. But to play your game, Switzerland and Italy, especially southern Italy, are very different.

Your counterexample is not even close to being accurate. Italy and Switzerland have much more in common than China and Japan. Italian is even one of the official languages of Switzerland. Switzerland and Italy are both essentially federations of distinct provinces. Both are recognizably Western European. China and Japan are worlds apart, as are China and India.

My main point was that there's plenty of reasons for China and Japan to be different, especially when it comes to driving norms. Are you surprised as the other poster was about these differences between China and Japan?

And going back to the original intent: would you say driving in Zurich and driving in Naples are two distinct experiences?

Re: One dead as London-Singapore flight hit by turbulence

#322

Post by alan-hn »

hollerith wrote: post #319
Andrews54757 wrote: post #317

Earlier quoted context omitted.

You won't gain additional momentum from a loose belt. But a loose belt may give your body the chance to slip out. The impulse you feel from a tight belt will be no less than the impulse you feel from a loose one.

>The impulse you feel from a tight belt will be no less than the impulse you feel from a loose one. I don't see any interpretation of that that makes it true.

Impulse is constant, its the force that is transferred to your body. This is constant whether or not a belt is worn.

A belt simply takes that force and redistributes it into the seat frame, if the belt is not worn the force is not redistributed by the belt but rather by your head into the overhead bin

Re: One dead as London-Singapore flight hit by turbulence

#323

Post by jerzmacow »

Andrews54757 wrote: post #317
scoofy wrote: post #235

Earlier quoted context omitted.

Right but what's the point? If the belt is on very loose, you give your body a chance to gain momentum, which will be redirected when the seat belt catches you, which would lead to serious injury. The belt doesn't need to be on tight, but it should be relatively snug. It's just one of those things that is trivial to do, with a very, very low probability to save you from injury, but costs nothing, so why not...

You won't gain additional momentum from a loose belt. But a loose belt may give your body the chance to slip out. The impulse you feel from a tight belt will be no less than the impulse you feel from a loose one.

I disagree, a tight belt will cause the least amount of injury. Look at fall arrest systems.

If you're harness is loose, or your line is slack without an energy absorber, it'll break your back when you fall!

Re: One dead as London-Singapore flight hit by turbulence

#324

Post by tdeck »

lxgr wrote: post #266
pintxo wrote: post #179

Earlier quoted context omitted.

The seatbelt light nowadays is mostly a don’t move around sign.

During take-off and landing, it is. At cruise altitude, it really does mean "the pilots are expecting turbulence and suggest you stay seated", at least in my experience. Of course they don't always get it right both ways: Sometimes reports of turbulence ahead turn out to be false positives, and at other times, strong turbulence can happen without any warning.

I've been on smoothe flights where the sign was kept on practically the whole time. Unfortunately I suspect some pilots forget about it, and I have observed that the public have gotten used to getting up to use the bathroom even when the sign is on (excluding takeoff and landing). I haven't flown enough to notice a pattern with specific routes or airlines.

Re: One dead as London-Singapore flight hit by turbulence

#325

Post by hollerith »

alan-hn wrote: post #322
hollerith wrote: post #319

Earlier quoted context omitted.

>The impulse you feel from a tight belt will be no less than the impulse you feel from a loose one. I don't see any interpretation of that that makes it true.

Impulse is constant, its the force that is transferred to your body. This is constant whether or not a belt is worn. A belt simply takes that force and redistributes it into the seat frame, if the belt is not worn the force is not redistributed by the belt but rather by your head into the overhead bin

It's like debt. If I'm standing on the ground, I'm constantly "making payments" to the ground. If I jump off a cliff, then while I am falling, I stop making payments, so when I next contact the ground, accumulated debt suddenly must be paid.

More precisely, while I am falling, my velocity and consequently my momentum relative to the Earth steadily increases, which is analogous to debt because I will eventually need to restore the situation in which my momentum relative to the Earth is zero (because that is how people live their lives: at rest relative to the surface of the Earth rather than for example in orbit).

In the same way, the passenger in the airplane must eventually go back to being at rest relative to the airplane, but if the seat belt is very loose, "debt" (momentum relative to the airliner) can be accumulated before all the slack has been taken out of the seat belt.

Yes, the total amount of impulse (change in momentum caused by the environment's pushing on the person) integrated over time is the same regardless of how tight the seat belt is, but it matters whether that impulse is spread out over time or comes in one big jolt.

Re: One dead as London-Singapore flight hit by turbulence

#326

Post by alan-hn »

hollerith wrote: post #325
alan-hn wrote: post #322

Earlier quoted context omitted.

Impulse is constant, its the force that is transferred to your body. This is constant whether or not a belt is worn. A belt simply takes that force and redistributes it into the seat frame, if the belt is not worn the force is not redistributed by the belt but rather by your head into the overhead bin

It's like debt. If I'm standing on the ground, I'm constantly "making payments" to the ground. If I jump off a cliff, then while I am falling, I stop making payments, so when I next contact the ground, accumulated debt suddenly must be paid. More precisely, while I am falling, my velocity and consequently my momentum relative to the Earth steadily increases, which is analogous to debt because I will eventually need t…

That doesn't make sense. Force is not accumulated by people standing on the ground, so your later analogy does not work at all

The ground opposes the force produced by gravity, there is no accumulation of anything. Gravity accelerates mass when it is pulling it in motion unless there is an equal and opposite force which is the normal force exerted by the ground (or airplane)

Re: One dead as London-Singapore flight hit by turbulence

#327

Post by 0x5f3759df-i »

yurishimo wrote: post #240
vsnf wrote: post #131

Earlier quoted context omitted.

This behavior is reflected in car attitudes too. Many Japanese drive with a detached seatbelt. Not even the presence of children changes this calculus.

Most Dutch people don’t wear a helmet when riding a bicycle. As e-bikes are becoming more popular, some older people are opting to wear a helmet since the speed is higher, but many still don’t. It’s not uncommon to see a parent riding around with a kid attached to the bike and neither are wearing a helmet. I think it is kind of a cultural thing as well as convenience. If you ride a bike to the station to catch a trai…

This really isn’t a similar comparison, Dutch infrastructure is built to prioritize making cycling safe at every decision point.

Whereas you’d be someone with a death wish to be riding without a helmet in most places in the US.

Re: One dead as London-Singapore flight hit by turbulence

#328

Post by throw310822 »

alan-hn wrote: post #322
hollerith wrote: post #319

Earlier quoted context omitted.

>The impulse you feel from a tight belt will be no less than the impulse you feel from a loose one. I don't see any interpretation of that that makes it true.

Impulse is constant, its the force that is transferred to your body. This is constant whether or not a belt is worn. A belt simply takes that force and redistributes it into the seat frame, if the belt is not worn the force is not redistributed by the belt but rather by your head into the overhead bin

The impact is a matter of energy, not of force- if the force applies for more than an instant, you keep accelerating before hitting the ceiling and the energy of the impact will be proportional to the square of your speed. If the belt is tight, you stop at a lower speed (relative to the aircraft) and the energy of the impact (with the belt, in this case) is lower.

Re: One dead as London-Singapore flight hit by turbulence

#329

Post by throw310822 »

bojan wrote: post #252
yurishimo wrote: post #240

Earlier quoted context omitted.

Most Dutch people don’t wear a helmet when riding a bicycle. As e-bikes are becoming more popular, some older people are opting to wear a helmet since the speed is higher, but many still don’t. It’s not uncommon to see a parent riding around with a kid attached to the bike and neither are wearing a helmet. I think it is kind of a cultural thing as well as convenience. If you ride a bike to the station to catch a trai…

Pricesely this, yes. And for the kids, an average trip to school takes like 5-10 minutes, hassling with three helmets (mine and of two kids) takes almost as long. And then I have to carry three helmets if I want to drop by to the supermarket after getting them to school. The bicycle seats for kids are designed in such a way that the only real danger of a head being hit is in the frontal collision, or in a really forc…

I thought that Dutch parents put small kids on the front of their bicycle to absorb the blunt of impacts. Then you dispose of the small child and make another one.

Re: One dead as London-Singapore flight hit by turbulence

#330

Post by seoulmetro »

ec109685 wrote: post #281
seoulmetro wrote: post #270

Earlier quoted context omitted.

I don't understand this weird line of thinking. Don't do positive X because some people might respond to it in a weird way and do neutral Y. Cattling statistics like this is silly. If you showed fat people images of obesity and said that they'd be healthier if they lost their weight, you would also cattle the statistics and look at how many fat people decided to suicide versus how many took the advice (or didn't)? Wh…

I mean if it caused a spike of suicides, I’d find a new message.

Yeah and that's incredibly dumb.
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