Is it just me or are people fucking thick?

[Mir Nyet]

OMG, I promised myself I would stay outta this thread but I need to join one of the groups in this here little bit of Ank Morpork.

On the assumption from the first post that the plane's situation

keeps it stationary. The question is, can the aeroplane take off?

The plane is not moving. The quote says so. It is stationary. No dice.

Someone mentioned a harrier jump-jet. Would an equivaltent situation be to put the harrier in a magical lift that lowered it to an infinite depth and the speed at which the jets pushed it upward?

Bigger question is, I know I am thick, but which group do I join and where can I get me some of this magic that's being used for everything?

Burn 'em all I say!

Dude, this is all so page 2

[diablo]

Great web page called - How does a Plane Fly?

http://www.raes.org.uk/raes/careers/edu ... planes.htm

Which has a bit that goes:

"Lift is the force that keeps an aircraft in the air... Lift can only be produced when air is moving over a wing."

Going back to our original premise of "Plane is stationary"

[kalmar]

ork.

On the assumption from the first post that the plane's situation

keeps it stationary. The question is, can the aeroplane take off?

The plane is not moving. The quote says so. It is stationary. No dice.

No, there's no condition stating that it's stationary. That's an assumption. If you look at the source of the quote, it says nothing about it being stationary.

People seem to imagine it could be kept stationary, but it wouldn't. It moves, therefore it flies.

Jedburgh didn't help by adding his own assumption to the quote, admittedly, but it's all been worked out in the thread if you care to read it.

Like even just read the second post in the thread. kthanks.

[tufty]

On the assumption from the first post that the plane's situation

keeps it stationary. The question is, can the aeroplane take off?

The plane is not moving. The quote says so. It is stationary. No dice.

The quote is a misquote. All the situation as linked to says that the treadmill matches the speed of the plane's wheels, nothing about whether the plane is stationary, moving, or whatever.

But you're right, it doesn't mention dice at all.

Simon

[Dio]

Never... in the history of this forum... has so much pointlessness... been spouted by so many... for so long...

[diablo]

but it's all been worked out in the thread if you care to read it.

Like even just read the second post in the thread. kthanks.

Point taken but absolutely no need to be so condescending. Really not an appealing way to point something out.

[D.J.Fudge]

My 2 cents

The energy of the planes engines is being transfered by a gear (the wheels) to the treadmill, causing the treadmill to move in the opposite direction.

So no movement though the air and no takeoff

[Jedburgh]

Never... in the history of this forum... has so much pointlessness... been spouted by so many... for so long...

Ace, isn't it?

[Dio]

No. No, it isn't.

[Roobarb]

STOP! STOP NOW!

This thread is making Sir Isaac Newton's ghost cry.

[Bog]

Alright children, gather around Unky Bog's knee, and we shall have Truth among us.

Imagine a plane is sitting on a massive conveyor belt, as wide and as long as a runway, and intends to take off. The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation.

Can the plane take off?

Therefore, groundspeed = 0.
Therefore, motion of wings through air = 0.
Therefore, lift generated by wings = 0.

The engines being wide open and screaming in full burner or being physically separated from the airplane and in packing cases full of Hello Kitty ribbon is irrelevant, unless you're specifically talking about e.g. an F-15 which can generate more thrust than it's own mass. Even then, it wouldn't "take off" so much as "flutter like a leaf in a gale before becoming an expensive FAA report"

Okay?

I love you all. Enjoy your pixies. Who wants candy?

[kalmar]

but it's all been worked out in the thread if you care to read it.

Like even just read the second post in the thread. kthanks.

Point taken but absolutely no need to be so condescending. Really not an appealing way to point something out.

Sorry, you're right that comment wasn't necessary.

[ClankClank]

Aaaaaaaaaaah!!!

It'a JET PLANE!!! Not a car!!!

A CAR pushes itself forwards using geared wheels. It pushes against the GROUND.

A PLANE pushes itself off against the AIR, by pushing lots and lots of it through it's engınes!!!

You can regard the wheels as providing a resistant force through the friction in their bearings, directly proportional to their speed in relation to the medium they are on, in this case the moving treadmill. Even if the plane is on the tarmac, moving at 200mph, they will experience some resistance. In this case, the surface is moving backwards at an extra 200mph- so the plane will be going a relative 400mph. Tough on the bearings maybe, but still THE PLANE TAKES OFF!!!!

NOT A CAR

A JET-PLANE

[kalmar]

Alright children, gather around Unky Bog's knee, and we shall have Truth among us.

Imagine a plane is sitting on a massive conveyor belt, as wide and as long as a runway, and intends to take off. The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation.

Can the plane take off?

Therefore, groundspeed = 0.
Therefore, motion of wings through air = 0.
Therefore, lift generated by wings = 0.

The engines being wide open and screaming in full burner or being physically separated from the airplane and in packing cases full of Hello Kitty ribbon is irrelevant, unless you're specifically talking about e.g. an F-15 which can generate more thrust than it's own mass. Even then, it wouldn't "take off" so much as "flutter like a leaf in a gale before becoming an expensive FAA report"

Okay?

No, it's not okay! Please Bog, not you as well. Honestly, can't you see why this is wrong? Seriously, this is getting to me.

Where do you get "ground speed = 0"? It just wouldn't be.

[Bog]

Gather under the banner, Non-Taker-Offers! We will do bloody battle 'gainst these fell beleivers in Rotate Speed on the Field of Victory! Rally to me! TO ME!!!!

*waves blue plastic sword around his head until kind people lead him away*

*edit* Kalmar, the whole thing's so daft I can't beleive you're taking it seriously! Please, chap, it's just a laugh. In the final analasys, the "thought experiment" itself is so ambiguous and daft that it really doesn't make any difference.

Though I am getting some hearty chortles out of it...