MythBusters

[sandorski]

LOL. The "Stationary" part of the Myth is the supposed result of the Treadmills affect on the Plane. AKA, the Plane would not take off because the Treadmill prevented the forward movement of the Plane. I'm not even sure what the point of the Plane being stationary is. The Treadmill wouldn't even be necessary and would be a poor way to test whatever Myth that was supposed to be about.

 

[gsellis]

Originally posted by: sandorski
LOL. The "Stationary" part of the Myth is the supposed result of the Treadmills affect on the Plane. AKA, the Plane would not take off because the Treadmill prevented the forward movement of the Plane. I'm not even sure what the point of the Plane being stationary is. The Treadmill wouldn't even be necessary and would be a poor way to test whatever Myth that was supposed to be about.

And that would only be possible if the acceleration of the belt allowed the inertia change in the rotation of the wheels through friction to generate enough force to counteract the thrust from the prop/jet/etc. That would way exceed the wording of the issue where the conveyor belt accelerated to match the forward speed of the plane.

And if you wonder how fast that is, apply the reverse observations, 0 to 180knots in less than 1 second does not stop the plane. It only generates tire smoke.

 

[Anubis]

i said it before and ill say it again


lot of stupid people in this thread

 

[Jodell88]

I may sound like a n00b but I don't care. I think the plane should not take off and this is why. Air needs to pass over a plane's wings to generate lift for it too fly right? Therefore i don't care how fast or slow a plane needs to move to generate sufficient lift, the point is air has to MOVE over the wings for it to takeoff. That being said if the plane stays stationary on the thread mill (like a person who uses one doesn't actually go anywhere), no lift would be generated and therefore the plane cannot take off.

If for some reason I am wrong in my logic please correct me.

 

[PurdueRy]

Originally posted by: Jodell88
I may sound like a n00b but I don't care. I think the plane should not take off and this is why. Air needs to pass over a plane's wings to generate lift for it too fly right? Therefore i don't care how fast or slow a plane needs to move to generate sufficient lift, the point is air has to MOVE over the wings for it to takeoff. That being said if the plane stays stationary on the thread mill (like a person who uses one doesn't actually go anywhere), no lift would be generated and therefore the plane cannot take off.

If for some reason I am wrong in my logic please correct me.

You're wrong but I won't correct you. I, and many others, have posted the reason why many times in this thread. Now there is video of it being busted. I refuse to type it out again.

 

[Fenixgoon]

Originally posted by: Anubis
i said it before and ill say it again


lot of stupid people in this thread

 

[waggy]

Originally posted by: sandorski
LOL. The "Stationary" part of the Myth is the supposed result of the Treadmills affect on the Plane. AKA, the Plane would not take off because the Treadmill prevented the forward movement of the Plane. I'm not even sure what the point of the Plane being stationary is. The Treadmill wouldn't even be necessary and would be a poor way to test whatever Myth that was supposed to be about.

not to mention how the props/jet engine work there is not way for it remain stationary. unless you have something holding the body of the plane. the wheels do not matter (well at least when the brakes are off).

 

[gsellis]

Originally posted by: waggy

Originally posted by: sandorski
LOL. The "Stationary" part of the Myth is the supposed result of the Treadmills affect on the Plane. AKA, the Plane would not take off because the Treadmill prevented the forward movement of the Plane. I'm not even sure what the point of the Plane being stationary is. The Treadmill wouldn't even be necessary and would be a poor way to test whatever Myth that was supposed to be about.

not to mention how the props/jet engine work there is not way for it remain stationary. unless you have something holding the body of the plane. the wheels do not matter (well at least when the brakes are off).

I think the word "treadmill" came into the whole thing because the idiots were too dumb to know what a conveyor belt was. But then, that fits the whole reason for why it is such a big deal. Too dumb to grasp the variables and see the solution. It really is a wonderful IQ benchmark.

 

[sao123]

Originally posted by: eits
i've arrived at the conclusion that this myth is a myth due to the fact that it's worded in a way that it could be taken in two different ways... either that or it's been spread around so much that people got the wrong idea of what the myth originally was.

i don't care to find out what the original myth is asking, so whatever. i'm going to bed.

and therein lies your problem.


The eording of the problem in its original form...


"A plane is standing on a runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in the opposite direction). Can the plane take off?"


nowhere in the problem does it say or assume that the plane has a 0 velocity to a nearby observer.

 

[mh47g]

This is how I understand how this would all work.

You have a plane.
We'll call its normal wheel speed at take off, 1x.
Even if you move a conveyer belt the opposite direction at 2x, 3x, or 10x, the only thing that will happen is that the wheels will spin that much faster.

 

[purbeast0]

lol @ eits.

 

[Papagayo]

I'm not sure, why lot of people are confused about this.

They should have done this test to explain to more simple minds.

have the plane stationary on the ground. If the plane can take-off at 25mph, then, they should have a fan that can blow 25mph wind directly to the stationary plane. The plane should take off at stationary position in reference to the ground.

 

[LegendKiller]

Originally posted by: waggy

Originally posted by: sandorski
LOL. The "Stationary" part of the Myth is the supposed result of the Treadmills affect on the Plane. AKA, the Plane would not take off because the Treadmill prevented the forward movement of the Plane. I'm not even sure what the point of the Plane being stationary is. The Treadmill wouldn't even be necessary and would be a poor way to test whatever Myth that was supposed to be about.

not to mention how the props/jet engine work there is not way for it remain stationary. unless you have something holding the body of the plane. the wheels do not matter (well at least when the brakes are off).

I don't think people really understand this. It doesn't matter if the treadmill tries to match ground, air, light, sound, unladen african swallow, or whatever speed. The speed of the treadmill makes absolutely no different on how the plane functions.

Sure, if the treadmill was going ludicrous speed, then the wheels might catch fire and crash the plane, but that's only if Dark Helmet controls the treadmill.

 

[Nyati13]

Originally posted by: cubby1223

Originally posted by: Banzai042
Yes, and the entire point of this myth is that there is literally no way at all in the universe that a treadmill can keep the plane stationary when the plane is trying to take off (short of having the treadmill spin at several thousand MPH, which is not at all what the myth says).

Nope.

Go watch the MythBusters episode again.

Both the treadmill and plane are given very specific speed constraints that they must adhere to to satisfy the myth. When the plane took off on the show, it had exceeded the myth's speed constraint.

The problem is the myth is assuming that the treadmill can constrain the airplane, which is false. There is no mechanism for a treadmill to stop an airplane from moving forward.

 

[jandrews]

The vast majority of the problems are that people just understand the myth differently. Most people arent idiots there are those that just thought that the plane would remain stationary or that was part of the myth when it wasnt. Simple explanation is the jet and wheels are seperate, the treadmill takes up the energy of the wheels but not of the jet engines therefore thrust will still be provided and the plane will still take off overcoming the negative reaction of the wheels on the treadmill.

 

[Nyati13]

Originally posted by: eits

you honestly think that a plane on a motherfucking treadmill will fly? if the plane is not displacing any distance, or if there's no wind under the wings, it cannot fly.

you might as well go to a flight school and call them numbnuts whenever they talk about lift and stalling. better yet, spend a bunch of your money and create an airplane that has an engine that only powers the wheels... that way, no pilot will ever stall... all they need to do is step on the gas.

:roll:

learn physics, dude.

http://wright.nasa.gov/airplane/lifteq.html

thinking that you'll fly when you're in a plane on a treadmill is like saying that you ran so fast you could feel the wind against your face when you're running on a treadmill.

The only way the airplane would not "displace distance" is if the airplane was not trying to take off ( ie, engines were at minimum).
The myth that began all this is that a treadmill can stop an airplane that IS trying to take off. And that myth is completely false, because there is nothing a treadmill can do to stop the airplane from "displacing distance"

 

[abaez]

I think my problem is that if I'm perpendicular to the treadmill and I am looking at the plane, the way I understand it is that the plane would not move forward with me looking straight at it. It would not go forward because the treadmill is basically "taking" the ground from under it and the plane is not moving forward. That's just how I see it - everyone says it's wrong, but since people say the treadmill cannot counteract, I just can't visualize it correctly.

If you take it another way, say a plane is landing onto a conveyor belt and the conveyor belt is matching the planes forward speed - if it lands on the belt perfectly wouldn't it just stay in the exact place it touched the ground not going forward? My mind tells me it would, but I'm sure it's wrong.

 

[KK]

Originally posted by: sao123

Originally posted by: eits
i've arrived at the conclusion that this myth is a myth due to the fact that it's worded in a way that it could be taken in two different ways... either that or it's been spread around so much that people got the wrong idea of what the myth originally was.

i don't care to find out what the original myth is asking, so whatever. i'm going to bed.

and therein lies your problem.


The eording of the problem in its original form...


"A plane is standing on a runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in the opposite direction). Can the plane take off?"


nowhere in the problem does it say or assume that the plane has a 0 velocity to a nearby observer.

do we have proof that this is the original way it was worded, and not what it has eroded to from being passed around the internet?

 

[sixone]

Originally posted by: abaez
I think my problem is that if I'm perpendicular to the treadmill and I am looking at the plane, the way I understand it is that the plane would not move forward with me looking straight at it. It would not go forward because the treadmill is basically "taking" the ground from under it and the plane is not moving forward. That's just how I see it - everyone says it's wrong, but since people say the treadmill cannot counteract, I just can't visualize it correctly.

If you take it another way, say a plane is landing onto a conveyor belt and the conveyor belt is matching the planes forward speed - if it lands on the belt perfectly wouldn't it just stay in the exact place it touched the ground not going forward? My mind tells me it would, but I'm sure it's wrong.

The problem with the first paragraph is that you're ignoring the fact that the propeller/engines are moving air past the plane as well, which gives it forward movement, regardless of whether the ground is moving or not.

If the plane is landing on the conveyor belt, it also has forward momentum, so it can't possibly stay in the same place. No conveyor belt can counteract that.

 

[LTC8K6]

The treadmill or conveyor cannot keep the plane stationary.

End of story.

Also, the myth never claimed the treadmill kept the plane stationary.

Those who think the treadmill can keep the plane stationary have yet to explain how it does this, except for odd scenarios where the wheel bearings get destroyed.

 

[KK]

Originally posted by: Nyati13


The only way the airplane would not "displace distance" is if the airplane was not trying to take off ( ie, engines were at minimum).
The myth that began all this is that a treadmill can stop an airplane that IS trying to take off. And that myth is completely false, because there is nothing a treadmill can do to stop the airplane from "displacing distance"

so you are saying that a plane not powered up on a belt moving in the reverse direction, would not start moving backwards?

Of course you are not that stupid to believe it wouldn't start moving backwards, therefore the plane is affected by the treadmill. And given that, it's possible on paper to stop the plane from moving forward.

 

[gsellis]

Originally posted by: LTC8K6
Those who think the treadmill can keep the plane stationary have yet to explain how it does this, except for odd scenarios where the wheel bearings get destroyed.

My new "Hell's Stairmaster" can do it. It is vertical instead of horizontal. Still have not figured out how to keep the F-15's from taking off though. I keep breaking the tails on the airplanes too when they roll off backwards.

 

[gsellis]

Originally posted by: KK

Originally posted by: Nyati13


The only way the airplane would not "displace distance" is if the airplane was not trying to take off ( ie, engines were at minimum).
The myth that began all this is that a treadmill can stop an airplane that IS trying to take off. And that myth is completely false, because there is nothing a treadmill can do to stop the airplane from "displacing distance"

so you are saying that a plane not powered up on a belt moving in the reverse direction, would not start moving backwards?

Of course you are not that stupid to believe it wouldn't start moving backwards, therefore the plane is affected by the treadmill. And given that, it's possible on paper to stop the plane from moving forward.

It is not possible on paper to keep it from moving. If it is, you are doing it wrong. The problem is folks think F of belt is on the plane, when what it really does is translates to delta V on the wheels, not the airframe.

 

[KK]

Originally posted by: gsellis

Originally posted by: KK

Originally posted by: Nyati13


The only way the airplane would not "displace distance" is if the airplane was not trying to take off ( ie, engines were at minimum).
The myth that began all this is that a treadmill can stop an airplane that IS trying to take off. And that myth is completely false, because there is nothing a treadmill can do to stop the airplane from "displacing distance"

so you are saying that a plane not powered up on a belt moving in the reverse direction, would not start moving backwards?

Of course you are not that stupid to believe it wouldn't start moving backwards, therefore the plane is affected by the treadmill. And given that, it's possible on paper to stop the plane from moving forward.

It is not possible on paper to keep it from moving. If it is, you are doing it wrong. The problem is folks think F of belt is on the plane, when what it really does is translates to delta V on the wheels, not the airframe.

So are you saying the belt has zero effect on the plane? Zero, Nada, Nil?

 

[LTC8K6]

In the scenario, the pilot is trying to take off, therefore the plane will not roll backwards like it did with the model test.

Unless the pilot is trying to take off without using the engine...

The only way folks can get the plane to stay still is to make up a different myth, or introduce ridiculous parameters.

The myth as stated for many years was blown to hell by Jamie and Adam.

Twice. Once with a model, and once with a real plane.

I would also like to add that Jamie clearly said that he just gunned the pickup, and the plane still took off normally, according to the pilot. Jamie went over the plane's take off speed and it still didn't even bother the plane.

Also, if you look at the cones, tha plane lifted off at approximately the same spot with and without the conveyor.