Bdog

How'd I miss that... oh well?

RogerPodacter

hope i dont spoil it for anyone. but adam stated that even the seasoned airline pilot experts got it wrong. and in the teaser video they play a clip of the pilot claiming that the plane will not take off, suggesting that in fact the plane does take off. but since the correct answer to this riddle is that the plane will in fact take off exactly as normal, with no wheel sliding or anything, then we wont be surprised.

is300eater

does anyone know if they are taking bets in Vegas on this?

The Dougler

iTrader: (1)

I'd put some coin on it, but i think even the bookies know its a sure thing.

JLatimer

Werd. It isnt gaming when you are just taking money from people who arent smart. It would be interesting to get a roll call of which side of the fence folks here are on before the show. Just so we know who to laugh at when it is all over.

Converted

Well, the answer is yes AND no... depending on if you use real-world psychics, or fake, theoretical-world physics...

This is simple:

In the "real world" yes the plane will take off.... reason being that the wheels have VERY little resistance, and cannot produce enough drag to actually have an effect on the planes forward speed. The plane is driven by THRUST, and not from power by the wheels... If anything, if this hypothetical treadmill "could" keep up and match the planes forward speed, then the wheels would spin so fast the wheel-bearings would have a complete failure, and the wheels would collapse....

In the "hypothetical" world, if there was a treadmill that could match the planes forward speed perfectly, regardless of what the wheels were doing, then no... it would NOT fly because it obviously needs forward movement, and air under the wings to fly. It's pretty cut and dry in the "fake" world... but in reality, the wheels are the thing that get people confused... because they don't produce the needed drag to even make the myth work.

Now, if you put some wheels on a plane that had a little resistance, then you'd see the effect of the resistance amplified, and the plane would NOT take off, due to the fact the treadmill would be able to keep up because the wheel's resistance is actually able to keep the plane's speed under the required speed for lift...

fdl

Wrong .. you've actually got it backwards. In the real world, the friction in the wheels may actually have an impact (although it's unlikely to be enough to stop the plane). In a theoretical world where the wheels have no friction, the treadmill has absolutely no effect on the forward movement of the plane, no matter how fast the treadmill is moving.

Converted

No, because in the "real world" there would not be a treadmill capable of going the speeds needed to even make the wheels fail...

You'll see... every test that they do, the plane WILL be able to take off... but they'll probably mention that in "theory" that if you were able to match the planes FORWARD speed (relative to the non-moving ground) 100%, the plane would not... but it's impossible to re-enact these circumstances...

fdl

I can't believe we're still debating this.

They are using a truck to pull back a tarp, and will match the planes speed exactly. So their real world experiment will generate enough speed. And in the real world, there is actually friction in the wheels of the plane which could provide some force against the plane taking off.

But taking this friction out of the picture, in a theoretical world, the plane will take off 100/100 times. A planes forward momentum has NOTHING to do with the wheels, its the thrust of the engines against the air.

Imagine you had a toy car with frictionless wheels. You placed it on a treadmill and held it there with your hands as the treadmill moved backwards at 50 mph. Your arm and hand here are like the power for the planes engine. Doesn't matter how fast the treadmill is going, you would not require additional force from your hand to keep it there or move it forward.

Converted

I've already said the SAME points you just said, including the thrust being the driving force... so who are you arguing with?

You're saying it WONT take off, in the real world and on the show?

It will.

dom

Now people who both say it will take off can't agree.

Converted

I know... he's attacking my post, yet saying the EXACT SAME THINGS I was...

I don't think he even read it... lol

fdl

You're saying the same point, but you aren't understanding it, as you still think the treadmill will play a factor , especially in a theoretical world.

I'm saying it WILL take off on the show, as long as the friction in the wheels is not too great ( which it shouldn't be) . In theory, with frictionless wheels, its a GUARANTEE to take off.

Converted

Oooohhhh.... so is it the wording I choose poorly, or do you just want to nit-pick to make yourself look smarter? lol

I also mentioned the fact that if the wheels had SOME friction to work with, the test would show different results, and it would likely NOT take off before they failed... but you must have missed that too.

fdl

If you think I am saying the same thing , its my post you aren't reading. You say the plane will not take off in a theoretical world, I say it will.

fdl

You say the plane will NOT take off in a theoretical world, I say it will. How is that nitpicking The fact that you think the plane won't take off clearly shows you do not understand the problem here. Its not nit picking.

rondog

iTrader: (1)

wind under and over the wings makes the plane fly or not at the full size scale. It won't work, now where's my money...

fdl

Anyways, if you truly are saying the same thing as me, that's fine. There is some miscommunication going on. Your post is incorrect or perhaps not clear when you say:

"In the "hypothetical" world, if there was a treadmill that could match the planes forward speed perfectly, regardless of what the wheels were doing, then no... it would NOT fly because it obviously needs forward movement, and air under the wings to fly. It's pretty cut and dry in the "fake" world... but in reality, the wheels are the thing that get people confused... because they don't produce the needed drag to even make the myth work."

Converted

I think the biggest problem here, is the way that the question is formed...

When this was originally brought into light in another forum I was on, they said the treadmill would match the wheels speed 100%, which would obviously negate any forward movement... but it was impossible to stop the plane from accelerating still because of the frictionless wheels...

Now, it appears that Mythbusters is ONLY taking the planes actual forward movent speed, into account... which is a whole different issue all together, and a simple answer.

If the plane requires 50MPH to take off, you can't simply have the treadmill going 50 MPH backwards, and expect it to hold the plane back... the plane wil take off easily, although the wheels may be spinning at 100MPH... obviously reason being, that the WIND AND AIR are the only true resistance factors, not the wheels.

If you did the same test, but said, a TAIL WIND will match the planes forward speed... the plane will NOT take off, EVER...

So I understand what you're saying, which is basically what I was saying... I was just assuming the treadmill matched the WHEELS speed in the "theoretical" question, until I watched that preview clip, and saw they're reffering to the plane's speed, which is lame.

Shalooby

The plane will take off, period. The speed of the treadmill has nothing to do with it.

Here's two scenarios: Something a little different and simple.

Plane on treadmill with no power from engine. Prevent plane from moving backwards once the treadmill starts moving in the opposite direction by erecting a fixture behind it to simply prevent it from falling off the back. It will remain staionary because the wheels will be spinning. DO NOT tether the plane to the treadmill in any way.
Start the engine and run it up to take-off power. It will move forward and fall off the front of the treadmill.

Now let me throw another twist into the argument that I haven't seen here yet. ( Unbelievable, huh )

Tether the plane to the treadmill using whatever means necessary however allow the wheels to spin as the treadmill runs. Now here's the twist. Put free spinning wheels on the treadmill itself. Place said treadmill - with wheels - and airplane tethered to treadmill on a runway. With the planes engine off start the treadmill and run it up to. . . hell, it doesn't matter, lets say 200 mph.
Now remember. The plane is tethered to the treadmill except for the wheels which can spin freely. The treadmill itself is on free spinning wheels and not tethered to anything.
With the treadmill running at 200 mph, start the engines of the plane and run them up to take-off power. Will the plane tethered to the treadmill move the whole thing forward?

Yes.

What does this prove? That a treadmill running underneath an airplane will have no effect on whether it will take off or not. It will.

Converted

Well, the only thing that this question needs to address is as follows:

You need to restrict the planes DRIVING force which makes it take off.

Wheels? Not a driving force...

Wind? Absolutely... create a tail wind, and it wont fly... create a 50MPH head-wind, and it can pretty much take off without even ROLLING, again proving the wheels have NOTHING to do with the planes movement... it's all in the air flow.

Think of a boat going UPSTREAM... if the boats max speed is 50MPH, and the river is flowing 50MPH downstread... the boat won't be going anythere, in relationship to the shore, because the boats driving force is directly affected...

Thinking that the plane WONT take off, is just ridiculous...

IlliNorge

When did head winds and tail winds enter the picture? Might as well talk about the radial velocity of the earth too. In relation to other celestial bodies this plane might be flying backwards.

Converted

Im simply illustrating to the people that don't get it... That WIND is the ONLY force that will affect a plane's take-off... end of story... not the wheels.

Shalooby

I completey agree.

My first career was aviation maintenance. I'm a licensed Airframe & Powerplant mechanic. There was a small flight school - Cessna 152s, 172s, about 15 of them - on the field and I insisted that they utilize the tie-down straps when parking the planes. Most of the time they just blew it off saying it's okay, the brakes are set. (Another problem altogether, we won't go there).
Well they had to learn the hard way when a spring storm came through one afternoon and almost half of their parked aircraft "took off". Some of them still had a hard time understanding how a plane could "fly" without moving.
It's simply a matter of the pressure differential created by the speed of the wind moving faster over the top of the wing than underneath it. Low pressure on top, high pressure on the bottom = lift.

RogerPodacter

OMG guys it doesnt matter, theoretical or real world, the plane always takes off. every time. it does. not. matter. about. the. treadmill. fdl sorry to disagree, but its just a simple thought experiement.



Tradmill Not Moving

<AIRPLANE>START-> -> -> -> -> -> -> -> -> -> -> ->-> ->TAKE OFF
---------------------------------------------------------------------
^plane starts here >>>>>>>>>>>>>>>>>>>>> ^plane takes flight here


Treadmill Moving Backwards

<AIRPLANE>START-> -> -> -> -> -> -> -> -> -> -> ->-> ->TAKE OFF
---------------------------------------------------------------------
^plane starts here >>>>>>>>>>>>>>>>>>>>>>^plane takes flight here


you guys cant see past the fact that the airplane will physically change locations, just like a regular take off, all the while the treadmill is spinning backwards. the wheels spin freely, so thrust pushes against the stationary air around it, not against the backwards moving treadmill. the plane still moves down the runway. it just has a conveyor moving backwards underneath it, so the wheels spin twice as fast. but it still moves forward. get it? no friction is involved. no wheels sliding. it just moves forward perfectly easy, just like normal. get it yet? there is no hypothetical vs real workd here, plane would take off every time in both worlds.

plane is not a car where the wheels are connected to the engines!! aggh. they are free spinning. they are free spinning.

there is no pressure involved in the thought experiment. of course once plane reaches speed the wings have pressure. but that is irrelevant in this question. the plane has forward motion, way further away from where it originally started. it physically moves locations, not stays stationary. because the wheels are not connected to the engines. how can you guys not get this by now? everyone at my work here sees the light. please think outside the box.

The Dougler

iTrader: (1)

for the sake of god, just wait until the 30th.

fdl

When did I say it wouldn't take off? Are you confusing me with someone else? I am clearly in the "It will take off" camp.

I said the friction in the wheels will have an impact, but it will still take off.

Now.. that said, if the friction in the wheels were very high (rusted bearings, etc), then its possible that the backwards moving treadmill would apply enough opposing force to prevent the plane from moving forward. Do you dispute this? If so, you are wrong lol.

RogerPodacter

oh sorry i mis read your other post. i thought you said it wouldnt. my bad!! but yeah, plane takes off like normal. no i agree with you completely here. there is very minor friction from the wheels. if the treadmill were going fast enough, that technically could counteract the plane thrust. but it would have to be some crazy high speed like thousands of mph.

fdl

Converted

I mis-understood him also, and thought he said it wouldn't... we were all confused there for a short while.

Where are the people that say it WONT????

pdub8

it WILL take off!!!


/thread

I cannot believe this is still going around.

The Dougler

iTrader: (1)

Can we get a temporary lock, until the show airs, then maybe re open and allow the people that don't get it to bitch about how mythbusters screwed up.

fdl

I move to ban bigman

Converted

Well... 80% of the time, Mythbusters DOES screw up... lol

But in any case, I'm sure they'll have the same result. Take off baby!!!

But seriously, who was arguing, saying it WOULDN'T?

The Dougler

iTrader: (1)

page 1-28ish

srika

swift22

can I start a new thread...

"if a train is traveling 60mph one way....."

LMAO

The Dougler

iTrader: (1)

and the track is matching it's speed in the opposite direction, what happens?

Converted

Crap... looks like I was late to the party.

Now all the "It won't fly" people aren't responding anymore, because we finally drilled sense into them, or what?

Smalls

when does this air? I dont want to read 32 pages. thx.