Hmm... in Quantum physics, you learn that when a mosquito and a train collide, they both actually stop.

I also think that everybody in the world has the same favorite color. I think that we all see different colors, but have grown up and been conditioned to know what the colors were by the worlds standards, but who says my blue is the same color of blue that you see? Prove it.

If you throw a pen in the air, does it have to stop at the top of it's path, to turn around and come back? If so, then how do you explain that something can stop if it is being accelerated on?? (gravity)

Just thought you might want a couple others to think about.

STan

 

You also learn that the bee may pass through the train too - now there is an interesting topic for discussion....

 

Oh! No! None of that wave-particle duality, Uncertainty Principle crap for me. I'll stick to the visible, measurable universe, thank you very much.

 

So is the cat dead or alive?

 

I'm going to have to refer to the experts on that one and say the answer is yes.

 

Alchymist you're a horrible man. Thanks to you I've had Schroedinger's stupid thought experiment stuck in my head for the last several hours. That ought to make for some interesting dreams.

 

I think I did a poor job of explaining my point. The plane still needs AIRFLOW over the wings to create lift. Just as someone else said, when you run on a treadmill, you feel no wind in your face regardless of how fast you run. The same principle would be applied in this case. I was trying to make the point in my post that if the speed at which the "treadmill" turns is equal to the speed of the airframe which is created by the thrust of the engines, then the two efforts should cancel each other and, in theory, there will not be enough airflow to create the necessary lift to achieve takeoff.

As for why I brought a pilot's opinion.....cause I could.

And remember, just because laws of physics say something should happen, doesn't mean it will. Aren't bumble bees supposed to be incapable of flight based on wing size relative to body weight according to physics?

Everyone will decide for themselves until a life size model can be produced

 

TKD... okay, you're running on a very long tread mill, say 100 yds. No wind in your face. Then someone comes along and straps jet engines to your back, skates to your feet, and wings to your outstretched arms. You fire the engines up and what happens? They push you forward off the end of the treadmill and you take off! Same exact thing.

EDIT: The Laws of Physics are Laws of physics. The part that doesn't always get it right is we humans in our application and understanding of how they work. They exist, we just don't have them all written down yet

 

TKD you are correct about airflow over the wing. Where you are making your mistake is with the treadmill analogy. When you run on a treadmill, you push against the conveyor to run. Those two forces cancel each othe out. When a plane takes off, it pushes against the surrounding air, not against the runway.

For your analogy to work, you would have to put on roller skates/blades and hold on to the hand rails. Turn on the treadmill and stand still. Does the treadmill throw you off? Why not, your not moving but the wheels are and they are not transmitting the force of the treadmill to your feet. Now pull yourself forward by using the handholds. Does it take any more force to move you forward than to stand still on the skates? Probably not much. You pulling on the hand rails is equivalent to the jet engines pushing on the air.

For the plane to not be able to fly it would have to have a driveshaft to the wheels on the landing gear and only move forward by the wheels turning. THEN the motion of the coveyor would cancel the motion of the plane. Since the plane is producting thrust OUTSIDE of the plane of the conveyor (jets/propellor pushing on the air), the conveyor cannot negate that thrust the plane moves forward on the conveyor and picks up speed, the air flows over the wing and the plane flys.

 

I understand what you both are saying. In my original post, I said that if the treadmill were self-powered and could exactly match the speed at which the wheels turn (and they will, based on the thrust moving the plane) then there would be be no airflow. If you are relying on the friction of the wheels turning to power the treadmill, then yes, theoretically, the plane might be able to lift off.

 

If only somebody would have said that earlier. (as I scratch my head and grin).

Hey, I've got a question. If, given this same experiment, you where to reverse the direction of the treadmill so that it where to run in the same direction as the plane and have the treadmill running at a faster rate than the plane. Given perfect static friction between the tires and the treadmill, could it take off then? Really? Think about it.

 

BTW: I'm offended that nobody has commented about the diagram I whittled up.

You bunch of ungrateful buttheads.



STan

 

My head still hurts!

I think what tkd means, the conveyor would have to match the airplane speed to keep it neutral. Not sure on math here, if the plane was moving forward at 10mph the belt would move 20mph in reverse to keep "da plane boss" in the same starting position. Hence plane would never move. I have no idea, but a old buddy of mine is dead and I will ask him to ask ole Orville! Wright!

Here goes another 9 pages!!!!

 

I praised you many times over on great diagram, but must have been on the conveyor and would not fly!!!!

Sorry, great art!! but will it fly?????

 

Yes the plane will fly unless someone puts a big *** logging chain from the tail of the plane to an even bigger *** post. Then there will be something to hold against the thrust of the engine. Until then, there is absolutely nothing holding the plane back.....