It's not lost on the mists of time if you learn how to use your handy-dandy time machine properly. You know, the same one Humber uses to freeze time on the belt.
The zen-like chain of thought began here...
The belt is just a source of power. What of a car on the a road? If you put a real car on a running belt, but do not start the engine, do you think that is the same as a car on the road?
Indeed it is so, Brother-monk. I used the Force, and the time-machine brought me to that saying. It is there in the text for our edification and enlightenment, praise be!
The reason I did not start there is that the verse was not merely the seed of our question, but the fruit of even earlier ones, as is so often the case.
The full text from which you quoted is finely crafted, as usual, and includes further insight, as follows:
The laminar flow moves with the wind.
For the above reasons, the contraflow of the belt will corrupt the experiment.
It is the wrong way, Brian-M
Ah, that great insight, "It's the wrong way." How often has that brought me comfort in zazen.
But this is not the best of the treatise. It continues (and please, do note the first statement well):
In real wind, the propeller drives the wheels. This force will generates a ground reaction to the rear of the driving axle.
The 'rear of the driving axle' - do you see?...
That force and the friction do generated propel the vehicle's axle until friction should break due to excessive force or whatever. This is in no way like the static (rolling) friction to the belt. That is low. That is why we use wheels.
...wheels, did you think of that?...but His Humberness goes on to give more than we could ever expect, showing how in all of this relative motion, the use of tyres is vital:
Tyres allow the wheel to change shape. They adapt to the load. High or low rolling resistance according to load.
...and, once again, why equivalence is not relevant here...
This cannot happen on the belt, because there is no load, which is why there is no axle movement on the belt, whereas there is in reality.
'there is no axle movement on the belt' - do you see? - if spork could only see the axle on the belt, he'd see it wasn't moving, because the wheels aren't being driven by the propeller, and the tyres aren't being deformed, because there is no load.
Then He posed another crucial point none of us are worthy to answer, but may contemplate in silence:
If not, why do you think a propeller driven by a belt is like a propeller in real wind?
What's the difference Brian_M? In the real world, the wind drives the propeller directly, exchanging real energy and the load of the cart as it is propelled forward. The belt can only drive the propeller, via the friction too the belt.
Wind drives the propeller. Obviously our thoughts and the whole thread has been going the wrong way for months, the art of DDWFFTW for years,
decades. Furthermore...
Not on the treadmill Bryan-M. It's topsy-turvy because the cart is going the wrong way, while equivalence useage contains some "upsidedownism"
...not only the wrong way, but upside down, probably inside out, and, more concisely...
I also found these dimensional visions of physics, probably way beyond most of us, which I had missed in the sacred scrolls before (because I had them on fast-sacred-scroll, I think):
I don't see the world the way you do. I think of all things being in one "frame" but containing different amounts of KE as a dimension. ... I think of velocity as a dimension, force and acceleration too. That is why I think of the cart as being in force "well". I don't impose that view on you. Just that it your ideas be consistent ,and correctly applied.
Do you see where we're going wrong? We don't see kinetic energy, velocity, force and acceleration as dimensions.
The learnings are vast in this chapter:
(1) There is no wind in the belt's frame of reference .
(2) As explained. Laminar flow is a flow. It does not make stops for photos.
On the treadmill there are two flows. They will always be distinguishable by the same test.
Two flows, you see? One room with the doors closed, but two winds. Not real ones, of course...
(3) Take a red and a blue smoke generator so as to colour belt and observer flows. Definitely not the same as real in wind. Do I win?
But do any of us bother to dig out our red and blue smoke generator and see if he wins? Of course not. Would we know what the belt and observer flows are? How could we, we who think that the wheels drive the propeller in both scenarios.
We don't even do proper experiments, like He does:
Spinning on the belt is just like being held back a bit. I did to some oranges at the supermarket checkout last week. Quite, easy really. Bananas have potential.
Which of us takes the time to explore the potential of bananas to roll on a treadmill? Has ynot tied one to his turntable? Has spork prodded one with a foon on his treadmill? I don't think so.
I really think this passage, which is one of His longer ones, is quite important, and I'm sorry I didn't trace the work back to it. There is only time to concentrate on some highlights today. One day, when our study is very good, we will unravel it all.
I hope you will forgive me Brother, for I did not know how far to trace back the question that has no answer. If I took one more jump in the time-machine, I could have confused things with your own troubled words to the Master that stimulated those teachings:
Brian-M said:
It's quite easy to show you how you are wrong. (The trouble is convincing you to accept the explanation.)
Take an observer, standing on the road with his palms facing forward and the wind at his back.
The wind is blowing at 10mph.
He lowers his hand to a height where, due to laminar flow, the wind on the back of his hand is only 7mph.
Now he moves forwards at 8mph.
He is still travelling at 2mph slower than the wind, but his hand is moving at 1mph faster than the laminar flow.
Consequently, he feels a 1mph headwind against the palm of his hand. That's how he can feel wind against the palm of his hand. He may be travelling slower than the wind, but he is travelling faster than the laminar flow.
If he tries the same experiment on a treadmill, on a windless day, he'll get exactly the same results.
Your "hand test" fails completely Humber.
Let us rejoice that such foolishness can be straightened out after all these lost centuries of going the wrong way.
Om mani padme humb.