No, John, The "velocities" are only the same is a very limited sense. Cart/wind velocity is local, wheres as the wind may be measured elsewhere. Measurement is critical. Inferring the speed from the relative velocities of cart and wind is not acceptable. I can make a faster cart if I can redirect the local airflow and measure it there. Hey, twice WS!
Did you mean to put 'Hey, twice BS!'?
On Monday I find I have no money in my wallet.
On Friday I find have no money in my wallet.
By looking at my wallet can I tell which of those days it is?
It could be that I do have money on the days between, with large transactions either way, or no money, any day.
I'd say it was some day after paying your bet money.
The velocity must not be inferred.
No. Indeed. The velocity (which is always and everywhere relative to something) must be measured. You measure the windspeed relative to the carpark and zoom off to see if the max speed you measure your machine at is more than that or if you need to tweak something, or you measure the speed of a treadmill, and put a cart on it, and see if it falls off the front or if you need to tweak something. I don't think anyone is suggesting any inference.
So, clearly John, I think the cart/wind zero velocity idea to be unreliable.
It's not an unreliable idea, it is a measurable condition that you have yourself already defined two different identical ways.
I would exclude it, but others hold it in value, so my remark was a compromise.
It seems much more likely that your remark was a fudge to try to steer somewhere between losing face and losing money. You make less and less clear statements the smaller that gap becomes.
I know that CW prop = CW wheels. If that means nothing to you, then you do not understand the treadmill argument at all.
CW prop may indeed equal CW wheels - I haven't bothered checking. CW prop could also equal CCW wheels, if, as I said last time, you change the gearing. Are you aware that if you put some gears together in a row, each turning the next, they turn in opposite directions? Do you realise that if you want your output rotation the other way, you can just add another cog in the line? Do you realise that the same switch can be performed by slipping the propshaft from one of the driving wheels to another, or by putting the gear on the other side of a driving wheel? Do you realise that it is feasible to make a propeller with the opposite angle or bias, as you like to call it, and make it push or pull even while it still goes CW? Do you realise that there are props that can slide gracefully from one angle to another and thus create thrust in either direction? Furthermore, do you realise that the idea of the wheels going CW or CCW is, as I said last time, an utterly meaningless condition unless you specify which side of the vehicle you are looking at? Do you realise that if you see a car go past and it's wheels are going CW, you can run across the road (do look first, won't you) and they'll be going CCW?
I do not value the treadmill. Dan O does, and wants to use it. I do not. I had idea how treadmill may be used to the satisfaction of both sides. Information gained denies the idea, but perhaps I was thinking of something else. Perhaps you can tell me what that was.
Perhaps I can tell you what you were thinking? What are you on?
On the treadmill, the amount of work done by the motor, is essentially the amount of energy dissipated by the propeller. Rotation does not affect that load, but the direction of the thrust.
Rotation indeed, as you say, affects the direction of thrust. There. That's a great start. You're getting the hang of aerodynamics now.
By your own reasoning you now understand why the treadmill is not what is claimed.
How so? What reasoning of mine? Do you mean a while back, where I pointed out some differences between the treadmill and a land test and agreed with a few others that they aren't likely to affect things at all but, contrary to spork, that strictly speaking one might say that the treadmill demo does not satisfy the wording of the claim? Or something related to your previous sentence, a convention most people follow when trying to convey meaning? You see, if it is that you are not satisfied with the equivalence doctrine or its use in this instance, then I guess you have to say that. You have to say that you won't accept a treadmill demo and then those interested in demonstrating it to you can decide whether to shrug and say they're not bothered what you think, or find another way to demonstrate it. I'd suggest they shrug, since you're just trolling anyway and, as spork said, aren't going to agree to any test.
Since there are supposed to be perfectly valid mathematical proofs, I don't know why a demo is really needed. But my personal experience is that, having been tricked by my intuition in the first instance, I now feel I have a sold intuitive grasp of the process, by reading, learning and thinking about it, and my reasoning does not show that the treadmill is "not what is claimed", in the sense you seem to be suggesting here. It is not exactly what is claimed, but all reasonable engineers and physicists agree that it is near enough a perfect 'boost', changing all significant velocities by the same amount, to validate the land-test situation, which is less controllable.
I pointed out those differences because I'm a bit pedantic. They are relevant in a strict sense, but their influence on the equivalence is, IMO, negligible. The trouble with you is that if a really careful treadmill test showed it to be true, you'd dismiss it. If some times later, several land tests proved it was true again, you'd dismiss it for some other reasons. There will always be some energy, thrust, rotation, momentum, work, force, power or ju-ju that you'll insist was wrong. You'd sit on one and ride at 3 times the speed of the wind directly downwind, get off and swear it doesn't actually prove that it works.
Also, on the real cart, CCW causes the wheels to move CCW, halting its forward progress. That you do not see the potential in that asymmetry, reflects badly upon your criticism.
Forget all about clocks. Clocks have nothing to do with it.
Ok. I will say this again one last time. All measurements of velocity are
relative (to the velocity of the observer, or some origin). That means that the treadmill equivalence is not just a modelling trick, but a true analogue of the road conditions other than those negligible effects I wrote of. All relevant speeds can be measured quite simply and very accurately. Furthermore, even the effects of the limitations of scale can be measured and shown to be negligible or otherwise.
Ask JREF if they are prepared to accept "Pixieview". A cart can move relative to the wind and ground and not be at windspeed. If a cart makes it upwind. What is the windspeed w.r.t cart? If it slips just a little backwards, then that is like going downwind at windspeed, so it must be zero? You can ask yourself how the speeds are defined in this case. Paradoxical, at times.
Maybe you really are serious. Maybe you really don't get it. If you do get it, it's a convincing bit of trolling, I have to admit. I can't tell which it is. Ah, yes, I think I most certainly can....
In 4-vector space conservation holds, as do Newton's laws. What is the integral of the "boots" over, say, 10 propeller turns?
If I'm not very much mistaken, you mever mentioned anything about 4-vectors until someone who understands them introduced the term. As you've done before with other technical terms, you post a moment later using the new words you've learned, pretending you know more about them (possibly having just googled them and gawped at a page of stuff for a few minutes). Then you tag a bit on, twisting the idea to your own ends. Do you even know whether
What is the integral of the boosts over 10 propeller turns? has any meaning?
The cart works because of the back-trenching of a gamut of foibles. If we take the mean of those foibles and back-trench them hard enough with respect to the rotation of the flange-arm (which is going CCCW, don't forget (East-West, UTC)), then the energy-matter-space-time continues measurably faster than the following wind, even up to steady-state electronics.
