Some objects, blown by the wind, go faster than the wind for as long as the wind is blowing. That is the point. That's also what the evidence shows. That is what you don't understand.
Please, explain! Prove that you can!
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Split Thread The validity of classical physics (split from: DWFTTW)
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Some objects, blown by the wind, go faster than the wind for as long as the wind is blowing. That is the point. That's also what the evidence shows. That is what you don't understand.
Please, explain! Prove that you can!
The cart is held in place by thrust from the propellor.
It would be if a force equal to that moving it backward off the belt were pushing it forward, thus putting it in equilibrium. As I said, this is supplied by thrust from the proppellor.
Which, in an idealised model, is all that is needed to prove the principal of DDWFTTW which is all the model is supposed to do!!
That is not enough to make the case valid. The power source is not correct.
The road is not the power source for the real wind.
The wind on the belt does not exist in any physical sense until the object on the belt is moving with the belt. It is quite clear that the force produced by this wind can be no greater than can be sustained by the friction to the belt. Friction to the belt is related to the rolling resistance and gravity. Therefore, the force of the wind is directly related to the force of gravity. That is not the case for real wind.
Another way to look at it is from the hobo perspective. The box, which I presume to be the "windspeed" case, is propelled by an unseen force.
On the treadmill, this is obviously not so, and there is a frictional coupling between that force and the cart.
This friction should be introduced into the hobo model, as it is something that cannot be avoided, and therefore not excluded. Let's say we simulate that by placing the box on a driven trolley, with the appropriate level of friction
between. This friction cannot be idealized, and can be exploited to tell me I am moving.
OK
There is a difference in the laminar flow. This is not so important. I am quite happy to say I am wrong, but I cannot see why. I made a drawing, but can't upload it. I will try again later.
Velocity is the only thing that is correct.
Well, I am trying to explain something that is to me rather obvious Brian-M.
That is a problem. But that is not all.
(1) The consequences of "bullet time" rivers. (No answer.)
(2) How about that you can't measure the KE, and that it looks exactly like it has near zero in all frames? (Unresolved at best.)
(3) If that's not true, how can the fork work? (No answer.)
(4) How is it that there is a difference in the behaviour of the wheels at windspeed? (ignored)
(5) How is it that Mender's experiments confirm what I said?
(6) He says he has to tune it to stay there! Not only does it support my contention, how is that related to the real road? Not at all.
(7) Or how the F1/BMW wind tunnel is not like a treadmill and has a stabilisor.
That is correct, but the frame equivalency is not held. That is my point.
Changing "frames" means changing between already constructed frames. The real train, on the real track, on the real planet. That means that you can change the physical aspects of those frames. You can't make the road the power source for the wind, because that is not so in nature. You could perhaps make a model this way, but then there are no real frames for comparison. Then only the accuracy of modeling counts. There are no equivalent frames for this model. That is a huge difference.
What it is, is the true equivalent of a belt set in the ground, with a cart on the track. That is correct. Going at windpeed, is the claimed simulation.
Yes, but you are again assuming that the treadmill is equivalent enough to make the comparison.
That means that you agree that the orthodox Newtonian explanation, without frames, is adequate to explain all matters of the cart. Apparently the meteorological balloob book, and Dr Drela's paper agree.
Please explain the role of the treadmill with reference to these.
Please explain why your direct evidence does not support my hovering claim.
Please supply evidence that has not already been dismissed showing objects can travel faster then the wind.
How is the friction force between the wheels and the belt different from that between the wheels and the road?
Not in any manner that anyone has agreed with.
No, it is not an exact equivellent, but it is an example of a similar thing- a system of supplying a relative velocity to model the real world.
Try this, if you put a powered model aircraft in the wind tunnel, and matched it's velocity through the air with the velocity of the wind in the tunnel, could it hover WRT the ground? If you then increased its thrust, would it move forward?
Would performance measurments of the aircraft made in the wind tunnel than be valid in the real world?
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I have.
Please quantify 'everybody'.
Wheels at windspeed to name one. They are not the same.
I doubt that. The cart is going backwards, not slowing. The speed is determined by the belt. You have to agree, or I will launch a velocity = displacement attack.
No need, because KE shows that this is the case. It changes for both the belt, ground and windspeed (the fork pusher) frames. It must do, because I can see its effects. What does the camera record?
If I apply an impulse force to the cart, why does it continues to "slow" after that force is no longer applied? Why does the acceleration of the cart remain apparently constant? Why does it go backwards in video #7.
I have already tried those, using springs and throwing masses from the cart. There are problems when these are conducted on the belt.
It seems to me that the explanation is clear. The windspeed fork is the equivalent of someone pushing from a car alongside the cart, which is the same as doing it from the road. This is because the road is common to the cart and car. The problem is that the belt is not the ground, but a moving road set in the ground. From that view, the treadmill tests are in accordance with the model.
No, No, Not all.
Dan O.
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Humber, you are trying to squirm out of answering by changing the subject again.
The question before you is for the cart on a surface with an apparent 10 mph tail wind relative to that surface. What force affecting the cart is going to reveal if it is a wind blowing over a road or a treadmill moving under the still air?
The question before you is for the cart on a surface with an apparent 10 mph tail wind relative to that surface. What force affecting the cart is going to reveal if it is a wind blowing over a road or a treadmill moving under the still air?
No. There is no possibility of the cart on the belt generating a drive patch behind the wheel axle. This is how cars move forward.
That would meann the car would no move. w.r.t the road/ground. Another coincidence.
Try this: No, it is not equivalent to the treadmill.
You can't reverse the direction of real cart, without first stopping it. I think that would cause a big reaction against the fork.
Dan O.
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That does not answer the question.
What force affecting the cart is going to reveal if it is a wind blowing over a road or a treadmill moving under the still air?
It is not about those principles, Brian-M, but the application. You ask for explanations, but somehow, the physical reality of the treadmill is jettisoned in favour of the hobo. It is about the real operation of the treadmill, and how it relates to its real world equivalent. The hobo may or may not be equivalent to either. There is no causation, Brian-M, or at least not enough.
ETA;
If you aver to those principles, Brian-M, then you should accept, without question, that the frame from the real ground, where I say I am standing should be the same. Equivalency does not allow you to declare frames invalid, or dictate which observer is "correct". You are violating the idea, yet I am holding to it.
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That does. It is no possible in real air, because wind power does not come from the road. You insist that your air-over-road is the same as road-over-air. Yes, but not when the power comes from the road. You have no wind to falsify.
You are so deluded and so wrong.
Sorry, I'm done playing your games. I'll wait for the explanation that you promised.
In the meantime, perhaps you can explain what is happening in this clip:
http://www.youtube.com/watch?v=MCB1Jczysrk
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This is not an important point, and I am willing to concede defeat, but I cannot see how I am wrong.
This is real wind. The laminar flow is a stack of layers, that slide over on another, yet they always move forward in the direction of the wind.
If the hand is placed so the wind is on the back of the hand, for speeds less than windspeed, I cannot see how the force can ever be felt upon the palm of the hand, if for no other reason than the hand would shield it.
As soon as the same observer moves up the belt, he will immediately feel the laminar flow upon his palm.
Dan O.
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You've started dropping words again. That is probably in indication of something.
I am not insisting that the road and treadmill scenarios are equivalent, I know they are. But I am giving you the opportunity to defend your position.
Given the cart on a road being pushed by the wind and an identical cart in still air being pushed the other way by a treadmill, what except for the fixed offset in velocities are you going to see different in action of the two carts.
OK, Mender. Will do.
I don't see how you can ask that, Dan_O. What you are saying is what is already understood about relative winds. But in effect, you are asking me to compare two different models.
There are a number of real-wind (windtunnel) treadmill examples, that would apply to your claimed case, but 'the' treadmill is not one of them .
All of the effects I claim are due to failures of that equivalency. They may appear to be detectable as simple differences of veloicty of the wind, or something else.
You insist on following this point, while ignoring the problem that the force of the treadmill wind, regardless of immediate detection, is related to gravity. That is so. The real wind is not like that, and that begets all the other effects.
I still think the laminar flow fits your demands, though. You don't agree, but I can't see why.
Please expand on gibberish. The cart cannot be propelled by the real wind to the road via the wheels, without a contact patch developing behind the axle in response to the applied force. That is necessary for motion.
It must be so of the prop driving the wheels to the belt
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If that were the case, and a patch were to develop, the cart could not remain in place. It's paradoxical. That paradox, discloses an error.
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