Merged DDWFTTW in a “Real” Wind

[humber]

hyev will tell you the compressed one has to weigh more - because it won't stay compressed on its own - it needs some sort of clamp. And you sure as heck can't find weightless clamps.

humber is likely to come up with some different offering of wrong.

Perhaps you would like to tell me why the TM cart is anything more than a device that stores all its KE in the angular components, and so has no linear KE.

Can you do that? With an MSc in control from UCLA in your pocket, that part of the design should be easy, so all that remains is the primary mechanism. Can you fault my proposal?

 

[humber]

It's not my job to find textbooks for you. As I and others have already explained to you, you will find that the propeller is acting as a propeller and textbooks will describe that behaviour as the normal behaviour of a propeller. I frankly neither know nor care whether any textbook exists which describes the similarity between the blade of a propeller and the sail of a yacht. It wouldn't surprise me at all, but I simply don't know if any do. That similarity exists nevertheless.

I am not raging that a prop isn't a prop, but that a there is no tacking force.
There are no text books that mention it, yet propellers are a fully mature technology. That may lead one to think that the claim of a tacking prop may be fantasy.

So what, exactly?
Which idea? Can I get to pick one? How about the one about stacking 2 sets of bathroom scales and seeing if they each register half your weight - was that one of yours?

It's related to this. I extemporized upon it to produce two stacked scales that each read half.
http://www.newscientist.com/article/dn2462-people-weigh-less-on-a-hard-surface.html

Springs;
F = -kx. x = extension. There is no dependency of k upon x, so k can be any realizable function. That's how things work, and why I know the TM is a trinket.

 

[zooterkin]

It's related to this. I extemporized upon it to produce two stacked scales that each read half.
http://www.newscientist.com/article/dn2462-people-weigh-less-on-a-hard-surface.html

Really? You do realise that article says nothing whatsoever to support your extemporisation, don't you?

 

[A.T.]

Now that's just funny. So if you stack to bathroom scales, they will each tell you half your weight?

Yes, that's what humber claims.

 

[CORed]

Really? You do realise that article says nothing whatsoever to support your extemporisation, don't you?

Of course he doesn't. If humber decided that the sky is green, he would cite an article that says it's blue, but on May 26, 1545, it was reported that the sky was green in Krakow, Poland, as evidence that the sky is green.

 

[humber]

Really? You do realise that article says nothing whatsoever to support your extemporisation, don't you?

Just because you can't see why, doesn't mean you understand it.
And I bet that you would have said the same about the result of that article, in the way you have mine. Materials strain; the load is inferred.

 

[humber]

Your precious TM is a trinket.

 

[GlennB]

It's related to this. I extemporized upon it to produce two stacked scales that each read half.
http://www.newscientist.com/article/dn2462-people-weigh-less-on-a-hard-surface.html

That article describes why bathroom scales register different weights on hard vs. deep carpeted surfaces. The reason being that on a hard surface the casing of the scales deforms (bows outwards at the base, because the little rubber feet raise the casing above the surface), causing internal fulcrums to become misaligned.

Do you have an ultra-deep sense of humour that nobody has yet understood?

 

[Jack by the hedge]

I am not raging that a prop isn't a prop, but that a there is no tacking force.

Can you expand on this a little - which force exactly is it that you think applies to the sail on a long reach which does not apply to the propeller blade with a similar angle of attack to the apparent wind?

It's related to this. I extemporized upon it to produce two stacked scales that each read half.
http://www.newscientist.com/article/dn2462-people-weigh-less-on-a-hard-surface.html

Springs;
F = -kx. x = extension. There is no dependency of k upon x, so k can be any realizable function.

Thank you for the Springs 101 reminder, but what do you mean about the stacked scales? Do you mean they read correctly when not stacked but read half each when stacked? I'd like to see what that design consisted of.

 

[A.T.]

That article describes why bathroom scales register different weights on hard vs. deep carpeted surfaces. The reason being that on a hard surface the casing of the scales deforms (bows outwards at the base, because the little rubber feet raise the casing above the surface), causing internal fulcrums to become misaligned.

This article about some specific scale layouts has nothing to do with humbers claims about bare springs in series.
http://talkrational.org/showthread.php?p=1189476#post1189476

Thank you for the Springs 101 reminder, but what do you mean about the stacked scales?

As usual, the root of humbers confusion is trivial, and yet impossible for him to overcome. He doesn't realize that the k in F = -kx is different for two springs in series than for just one. So he assumes that two springs in series will have the same x as one spring, if F is the same.

Needless to say that empirical evidence doesn't convince him:
http://talkrational.org/showthread.php?p=1190200#post1190200

 

[humber]

Can you expand on this a little - which force exactly is it that you think applies to the sail on a long reach which does not apply to the propeller blade with a similar angle of attack to the apparent wind?

A tacking boat takes a longer path than ddw. Work = F*d
The prop takes the same path as the cart and wind when ddw. That is why there are no tacking props in any text book. Why do you think that they would have missed that?
Lancaster couldn't "see" the angled blade?

Thank you for the Springs 101 reminder, but what do you mean about the stacked scales? Do you mean they read correctly when not stacked but read half each when stacked? I'd like to see what that design consisted of.

Well if it's springs 101, then you should be able to design the scales so that when stacked each will read half the reading when on the floor.
Why should I tell you how that is done? You accepted the TM as is.

 

[humber]

As usual, the root of humbers confusion is trivial, and yet impossible for him to overcome. He doesn't realize that the k in F = -kx is different for two springs in series than for just one. So he assumes that two springs in series will have the same x as one spring, if F is the same.

You tell the load cell designer where he went wrong. I am waiting.
A button cell can read correctly even if the load is at 45 degrees, and the same when normal to the button. How is that done?

You repeatedly post my diagrams, accompanied by your opinion even though I have asked you not to. So I would like you to show that you have the expertise to do so.

 

[zooterkin]

Just because you can't see why, doesn't mean you understand it.
And I bet that you would have said the same about the result of that article, in the way you have mine. Materials strain; the load is inferred.

The article is about bathroom scales on hard or carpeted surfaces. Please explain your leap of logic which has led you to believe that it means that stacked scales will only read a fraction of the weight upon them. Are you assuming the scales have a carpeted upper surface?

 

[humber]

The article is about bathroom scales on hard or carpeted surfaces. Please explain your leap of logic which has led you to believe that it means that stacked scales will only read a fraction of the weight upon them. Are you assuming the scales have a carpeted upper surface?

Then it's up to you to learn how that may be done. ( The solution is far from simple)
I am not interested. The point being that Carteers have nothing but hubris to support their claims, and A.T in particular, insists on re-posting things he does not have a clue about, yet posts cartoons as physics.

The topic is the cart in the wind. As far as I am concerned, the TM is irrelevant, and that is also the opinion of Dr Camp.
As an aside, the topic of springs came up because of a remark made by Yevgheni about the TM and the way it supports a load. That was not understood, so that resulted in springs 101.
It' a mistake to try and educate.

 

[Jack by the hedge]

A tacking boat takes a longer path than ddw. Work = F*d
The prop takes the same path as the cart and wind when ddw.

The hub of the propeller follows the same path as the cart. The blades of the prop follow a longer spiral path, and work is done turning the prop to accomplish this. So your objection appears to be baseless.

Well if it's springs 101, then you should be able to design the scales so that when stacked each will read half the reading when on the floor.
Why should I tell you how that is done? You accepted the TM as is.

I can understand how the treadmill works. I don't take it on trust. If a 90kg man stands on a set of bathroom scales, it should read 90kg. If he places the scales (which weigh, say, 1kg) on top of another set of scales and climbs on top, the top set of scales will read 90kg and the lower set of scales will read 91kg.

If you have an arrangement where they both read 90kg when used individually but also read 45kg each when stacked on top of each other then I'd like to understand how you propose it would be done.

 

[Jack by the hedge]

Then it's up to you to learn how that may be done. ( The solution is far from simple)

I have no confidence that you have a real solution and have not made an elementary mistake.

 

[ThinAirDesigns]

I kind of thought...

(You really shouldn't even try)

... Jack Goodman's video on Youtube was where that really got started on the net. Do you know the dates when Jack's cart first appeared? When was yours on the kite surfing site?

Before that.

JB

 

[ThinAirDesigns]

You said that you and NALSA had a good laugh over the e-mails I sent them, ...

This is an unequivocal lie.

JB

 

[humber]

I have no confidence that you have a real solution and have not made an elementary mistake.

No, I won't expand on it more than this. An S cell has an arm that takes the load. The displacement of that arm is like a simple spring, but how the cell is mounted to the floor or support, changes that. It can read zero just by moving the mounting, even though the arm works just the same. Strain is distributed in 3 dimensions. Engineers use their imagination and skill to solve problems, and don't take simplified wikis as the entire picture, and throw their arms up and say it can't be done.
Similarly, the TM is seen as a simple V1 -V2 = 0, "Galilean Transform" so it must work, when the reality is more complex.
The initial reaction that the cart can't climb the belt is correct. I works around that.

 

[humber]

This is an unequivocal lie.

JB

Fish in a barrel.
It was NASA.

True. JB and I had the advantage of speaking with the NASA engineers directly. They of course had to laugh at humber's emails just as we laugh at his lies and delusions here. After a very short time, they proved themselves smarter than the rest of us by choosing not to engage these cranks any more.

1) I wrote to the manager, not Smith
2) Spork and you denied knowing Smith
3) He finally admitted that he met Spork through flying.