MythBusters

[Jeff7]

Sneak peek - really crappy audio

 

[HydroSqueegee]

Originally posted by: CorCentral

Originally posted by: HydroSqueegee
who in their right mind would think the plane takes off?

You are joking right? Surely you are.

Here's a simple Test that was done on You Tube. Nothing fancy, but it shows what you need to see. The guy in the video even makes a reference to MythBusters. If you don't believe him, watch the Mythbuster's episode coming up he says.

Maybe im a little dense, but as far as i can tell, it wont have enough speed to generate lift for it to take off. I dunno, im no aeronautical engineer.

 

[Jeff7]

Originally posted by: HydroSqueegee
Maybe im a little dense, but as far as i can tell, it wont have enough speed to generate lift for it to take off. I dunno, im no aeronautical engineer.

My thinking along these lines: Put jet engines on an aerodynamic mass (mass = that of an airplane) without wings, or abnormal shapes - JUST wheels. Then, fire up the engine, and see how fast the thing will go. Once it levels out, record that speed. That will record the maximum speed that the engine can possibly move that mass, given the resistance of the wheels. This is going to be a pretty darned high speed though.

Then, set the treadmill to equal that really high speed. THEN, the plane will be unable to move forward.

All of this ultimately depends upon the wheels - the amount of backward force they will impart to the body of the plane as a result of bearing friction is dependent entirely upon the speed that the treadmill moves. And therein lies part of the problem: Treadmill speed = f(x). What is x? Engine speed? Wheel speed? Pi?

 

[HydroSqueegee]

The plane is not going forward, therefore no air is passing over/under the wings which equals no lift. It will not take off. There is simply nothing there to LIFT it.

 

[timosyy]

Everyone just needs to watch this damn youtube video (which was posted earlier but I'm linking it again):

http://www.youtube.com/watch?v...COzDiE&feature=related

The plane takes off. Mythbusters should just link that video too /sigh

Edit: Once the plane has enough thrust to overcome rolling friction of the wheels, it doesn't matter how fast the conveyor belt is going, more thrust makes the plane go forward.

 

[Rubycon]

LOL

They are using a truck to pull a tarp in the opposite direction. :laugh:

And yes the video posted above proves that the plane can move forward even if the belt is moving faster than the plane would on its own. If it can move forward it can take off.

 

[CorCentral]

Originally posted by: timosyy
Everyone just needs to watch this damn youtube video (which was posted earlier but I'm linking it again):

http://www.youtube.com/watch?v...COzDiE&feature=related

The plane takes off. Mythbusters should just link that video too /sigh

Edit: Once the plane has enough thrust to overcome rolling friction of the wheels, it doesn't matter how fast the conveyor belt is going, more thrust makes the plane go forward.

Here's another video posted by the same guy, explaining it mathematically. Just subtract the "tape" part. That was from an older video.
He not too articulate with his words, but he knows what he's talking about.
HERE

 

[BeauJangles]

Originally posted by: HydroSqueegee
The plane is not going forward, therefore no air is passing over/under the wings which equals no lift. It will not take off. There is simply nothing there to LIFT it.

Here are two ways to think about it:

1) Imagine a car on a treadmill. The car derives the force necessary to move it forward by the tires spinning and friction with the ground. Put a car on this mythical treadmill and it won't move forward - right? The faster the wheels spin, the faster the treadmill spins. No movement.

Why isn't this true of a plane? A plane does not push against the ground to move forward. The jets, props, whatever push against the air around the plane. Think about sea planes. They take off and land on the water and don't have anything to propel them through the water. The wheels are only attached to a plane to reduce friction between the plane and the ground - they don't actually propel the plane at all.

2) Imagine you're on a treadmill with roller blades. (let's assume there is no friction) When you turn on the treadmill to 5 mph your wheels will spin at 5 mph and you will go nowhere, right? Increase speed as much as you want, but your feet won't move at all. Now, imagine there is a rope attached to the wall in front of you. When you grab the rope and pull, what happens? You move forward. Why? Because the force of the rope is independent of the forces acting on the wheels on your roller blades. A jet engine works the same way. It acts completely independently of anything going on underneath it.

Let me know if you'd like further clarification. I'll do my best to explain.

 

[manowar821]

I think they're just sick of people bullshitting and saying that the plane will take off.

 

[Nyati13]

Originally posted by: Jeff7

Originally posted by: HydroSqueegee
Maybe im a little dense, but as far as i can tell, it wont have enough speed to generate lift for it to take off. I dunno, im no aeronautical engineer.

My thinking along these lines: Put jet engines on an aerodynamic mass (mass = that of an airplane) without wings, or abnormal shapes - JUST wheels. Then, fire up the engine, and see how fast the thing will go. Once it levels out, record that speed. That will record the maximum speed that the engine can possibly move that mass, given the resistance of the wheels. This is going to be a pretty darned high speed though.

Then, set the treadmill to equal that really high speed. THEN, the plane will be unable to move forward.

All of this ultimately depends upon the wheels - the amount of backward force they will impart to the body of the plane as a result of bearing friction is dependent entirely upon the speed that the treadmill moves. And therein lies part of the problem: Treadmill speed = f(x). What is x? Engine speed? Wheel speed? Pi?

But that isn't true. The maximum speed is not determined by wheel friction, it's determined by wind resistance. Wheel bearing friction is tiny compared to wind resistance.

 

[jandrews]

Originally posted by: BlinderBomber

Originally posted by: HydroSqueegee
The plane is not going forward, therefore no air is passing over/under the wings which equals no lift. It will not take off. There is simply nothing there to LIFT it.

Here are two ways to think about it:

1) Imagine a car on a treadmill. The car derives the force necessary to move it forward by the tires spinning and friction with the ground. Put a car on this mythical treadmill and it won't move forward - right? The faster the wheels spin, the faster the treadmill spins. No movement.

Why isn't this true of a plane? A plane does not push against the ground to move forward. The jets, props, whatever push against the air around the plane. Think about sea planes. They take off and land on the water and don't have anything to propel them through the water. The wheels are only attached to a plane to reduce friction between the plane and the ground - they don't actually propel the plane at all.

2) Imagine you're on a treadmill with roller blades. (let's assume there is no friction) When you turn on the treadmill to 5 mph your wheels will spin at 5 mph and you will go nowhere, right? Increase speed as much as you want, but your feet won't move at all. Now, imagine there is a rope attached to the wall in front of you. When you grab the rope and pull, what happens? You move forward. Why? Because the force of the rope is independent of the forces acting on the wheels on your roller blades. A jet engine works the same way. It acts completely independently of anything going on underneath it.

Let me know if you'd like further clarification. I'll do my best to explain.

I dont know if you just dont understand but you are not answering his question at all. He is saying that a plane will not take off because there is no air moving under the wings to provide lift regardless of the propulsion of the jet engines.

All your answers respond to someone stating that jet engines dont do much and the wheels are a factor but dont address his comments at all.

A better more simple question would be why do planes have wings at all? According to people who say the engines provide all the lift why not just make a plane that is submarine shaped (taking turning out of the equation of course).

 

[Phokus]

You'd think a reputable Aerospace engineer or physicist would've put the nail in the coffin on this stupid debate by now.

 

[JoLLyRoGer]

THE PLANE FLYS GODDAMMIT!!!! AARGHHH!!1!!

<< JR beats his head bloody against the wall

Please GOD, Please just let them see!!! THE FUCKING PLANE FLIES!!!

The wheels....., on the bottom of the plane......., HAVE JACK BUPKISS TO DO WITH POWERING THE PLANE DOWN THE RUNWAY - OR EVEN THROUGH THE AIR FOR THATMATTER!!!

Now LET - IT - GO ALREADY!!!

 

[jandrews]

Originally posted by: JoLLyRoGer
THE PLANE FLYS GODDAMMIT!!!! AARGHHH!!1!!

<< JR beats his head bloody against the wall

Please GOD, Please just let them see!!! THE FUCKING PLANE FLIES!!!

The wheels....., on the bottom of the plane......., HAVE JACK BUPKISS TO DO WITH POWERING THE PLANE THROUGH THE AIR!!!

Now LET - IT - GO ALREADY!!!

but u bastard the air lift under the wings do have something to do with it. There is no wind under the wings when the plane is stationary rarrgg!!!

 

[pnad]

The plane is NOT stationary. That is the point. The treadmill is incapable of keeping a plane stationary.

 

[JoLLyRoGer]

Originally posted by: dainthomas
Every time someone says the plane doesn't take off, God kills a kitten.

I don't know why, but that actually made me laugh out loud! :laugh:

 

[jandrews]

Originally posted by: pnad
The plane is NOT stationary. That is the point. The treadmill is incapable of keeping a plane stationary.

so when you are running on a treadmill you feel the wind picking up and blowing in your face when at the gym? lmao, uh no.

 

[dainthomas]

Originally posted by: jandrews

Originally posted by: JoLLyRoGer
THE PLANE FLYS GODDAMMIT!!!! AARGHHH!!1!!

<< JR beats his head bloody against the wall

Please GOD, Please just let them see!!! THE FUCKING PLANE FLIES!!!

The wheels....., on the bottom of the plane......., HAVE JACK BUPKISS TO DO WITH POWERING THE PLANE THROUGH THE AIR!!!

Now LET - IT - GO ALREADY!!!

but u bastard the air lift under the wings do have something to do with it. There is no wind under the wings when the plane is stationary rarrgg!!!

The wheels cannot keep it from moving. If you put wheels on the side of a Saturn V rocket and ran a vertical treadmill underneath, it would still take off.

I really cannot wait for this show so people will STFU.

 

[JoLLyRoGer]

Originally posted by: jandrews

Originally posted by: pnad
The plane is NOT stationary. That is the point. The treadmill is incapable of keeping a plane stationary.

so when you are running on a treadmill you feel the wind picking up and blowing in your face when at the gym? lmao, uh no.

That's because I'm not wearing a friggin JET PACK strapped to may ASS!

 

[dainthomas]

Originally posted by: jandrews

Originally posted by: pnad
The plane is NOT stationary. That is the point. The treadmill is incapable of keeping a plane stationary.

so when you are running on a treadmill you feel the wind picking up and blowing in your face when at the gym? lmao, uh no.

If I was wearing a jet pack and wearing roller skates I would.

 

[Cerpin Taxt]

The plane takes off, and anyone that thinks otherwise *cough*jandrews*cough* is seriously detached from reality.

If I was an employer, I would put this question on the new applicant questionnaires in order to separate the idiots from the people that can actually think.

 

[jandrews]

Originally posted by: dainthomas

Originally posted by: jandrews

Originally posted by: pnad
The plane is NOT stationary. That is the point. The treadmill is incapable of keeping a plane stationary.

so when you are running on a treadmill you feel the wind picking up and blowing in your face when at the gym? lmao, uh no.

If I was wearing a jet pack and wearing roller skates I would.

So, am I correct in understanding that you believe that someone who is on a treadmill where the track moves under them will somehow work up wind resistance when they reach a certain speed? I cannot even explain how insane that sounds. I feel like I am in the twilight zone where everyone else is crazy and I am the only sane one but they all believe they are sane. I dont care what you say, there is no way that an object on wheels that remains in the same position as it started will build up wind resistance.

 

[pnad]

Originally posted by: jandrews

Originally posted by: pnad
The plane is NOT stationary. That is the point. The treadmill is incapable of keeping a plane stationary.

so when you are running on a treadmill you feel the wind picking up and blowing in your face when at the gym? lmao, uh no.

No, but I would fly off the treadmill in a hurry if I had a jet on my back dumbass.

 

[jandrews]

Originally posted by: pnad

Originally posted by: jandrews

Originally posted by: pnad
The plane is NOT stationary. That is the point. The treadmill is incapable of keeping a plane stationary.

so when you are running on a treadmill you feel the wind picking up and blowing in your face when at the gym? lmao, uh no.

No, but I would fly off the treadmill in a hurry if I had a jet on my back dumbass.

Thats not part of the myth, as I understood it the myth is as follows

A plane on a treadmill of infinite length, can it take off? You must truly be a f'ing idiot if you're whole idea is that the myth is fake because the plane will fall off the treadmill, move on the ground and then take off, talk about 'special', let me know if you need help understanding my concept.

 

[sdifox]

Originally posted by: jandrews

Originally posted by: BlinderBomber

Originally posted by: HydroSqueegee
The plane is not going forward, therefore no air is passing over/under the wings which equals no lift. It will not take off. There is simply nothing there to LIFT it.

Here are two ways to think about it:

1) Imagine a car on a treadmill. The car derives the force necessary to move it forward by the tires spinning and friction with the ground. Put a car on this mythical treadmill and it won't move forward - right? The faster the wheels spin, the faster the treadmill spins. No movement.

Why isn't this true of a plane? A plane does not push against the ground to move forward. The jets, props, whatever push against the air around the plane. Think about sea planes. They take off and land on the water and don't have anything to propel them through the water. The wheels are only attached to a plane to reduce friction between the plane and the ground - they don't actually propel the plane at all.

2) Imagine you're on a treadmill with roller blades. (let's assume there is no friction) When you turn on the treadmill to 5 mph your wheels will spin at 5 mph and you will go nowhere, right? Increase speed as much as you want, but your feet won't move at all. Now, imagine there is a rope attached to the wall in front of you. When you grab the rope and pull, what happens? You move forward. Why? Because the force of the rope is independent of the forces acting on the wheels on your roller blades. A jet engine works the same way. It acts completely independently of anything going on underneath it.

Let me know if you'd like further clarification. I'll do my best to explain.

I dont know if you just dont understand but you are not answering his question at all. He is saying that a plane will not take off because there is no air moving under the wings to provide lift regardless of the propulsion of the jet engines.

All your answers respond to someone stating that jet engines dont do much and the wheels are a factor but dont address his comments at all.

A better more simple question would be why do planes have wings at all? According to people who say the engines provide all the lift why not just make a plane that is submarine shaped (taking turning out of the equation of course).

How is the treadmill going to keep the plane static? air is being sucked into the jet engine and pushed out back, the wheel is there to keep the plane from hitting ground, not to propel it.