DDWFTTW Turntable Test: 5 Min Video - Is It Conclusive?

[ThinAirDesign]

Aaaaand with just a bit of elementary school math (1 / 2.4) we see that this means the cart is exceeding the windspeed by 1.41x.

Make that ((1 + 2.4) / 2.4).

Your way works as well, but doesn't invalidate mine, that's for sure.

Either way the end result is the same -- ~40% greater speed than the wind DDW.

JB

 

[rcgldr]

(1 / 2.4) exceeding the windspeed by 1.41x.

((1 + 2.4) / 2.4).

Either way the end result is the same

Sorry for getting picky. I was just trying to cover any potential comments from the doubters.

 

[cesiumfrog]

I got 2.33 examining a captured video frame by frame, instead of 2.4 but close enough.[...] 1.4167 times wind speed.

Could you elaborate on the uncertainty of your measurement ("close enough" on what grounds?). How many of those five significant figures do you think are completely incorrect?

Sorry for getting picky.

I don't think schroder is disagreeing with your statement that the cart, relative to the turntable, goes DDWFTTW. He just thinks it is occurring by a mechanism unrelated to how a cart on the ground behaves in uniform wind. (And thinks each independent item of evidence is also flawed, in just such a way that they all present the same false-conclusion.)

A heterodyne is most clearly understood when considering radio or audio frequencies but it most definitely is applicable to any mechanical frequencies as well. [..] I suggest you study up on it!

Schroder, could you give a reference for the concepts "heterodyne" and "Bessel null" being applied to a mechanical system, so that I may study up on it?

 

[rcgldr]

rotation of TT versus cart. I got 2.33 examining a captured video frame by frame, instead of 2.4 but close enough. ... 1.4167

Could you elaborate on the uncertainty of your measurement ("close enough" on what grounds?). How many of those five significant figures do you think are completely incorrect?

Three. The video only gives me 1/30 of a second revolution, and I got about 2 1/3 TT revolutions per cart revolution. The cart is accelerating a small amount until the last 2 or so revolutions, so I couldn't pick spots over a longer time period. The 1.4167 was just (3.4 / 2.4), but realistically 1.4 would be a more valid ratio.

So to be valid, I'll restate this as the last 2 revolutions of the cart are about 1 / 2.3 that of the TT, and the last 5 or so average out to be about 1 / 2.4. In either case, the cart speed would be about 1.4 times wind speed.

DDWFTTW. He just thinks it is occurring by a mechanism unrelated to how a cart on the ground behaves in uniform wind.

It seems that if the cart were placed at a latitude very close to the pole of the earth, then the Earth's movement (eastward) relative to the pole would be very close to that of the TT. Add in a wind that moves westward relative to the pole as the same speed that the Earth's surface moves eastward relative to the pole, so that the wind isn't moving with respect to the pole, and the situation is very close to the TT situation.

 

[schroder]

I don't think schroder is disagreeing with your statement that the cart, relative to the turntable, goes DDWFTTW. He just thinks it is occurring by a mechanism unrelated to how a cart on the ground behaves in uniform wind. (And thinks each independent item of evidence is also flawed, in just such a way that they all present the same false-conclusion.)


Schroder, could you give a reference for the concepts "heterodyne" and "Bessel null" being applied to a mechanical system, so that I may study up on it?

It appears you are the first person here to at least try and understand what I am talking about.
If you Google “mechanical resonance in rotating machinery” you will find many interesting sources of information. Unfortunately, most of these sources deal with vibrations, rather than with heterodynes. The difference is that vibrations seldom achieve a true Bessel dropout and a change in operating mode. Vibrations are generally unwanted in rotating machinery and the main courses of study are aimed at ways to reduce them. I have considerable experience with vibration analysis, having worked personally with Ralph Buscarello of Update International in the past. It is because of this experience that I am able to recognize this heterodyne. BTW he has an excellent on-line textbook you may find helpful at this link:
http://www.update-intl.com/VibrationBook.htm
What is intriguing about the cart and turntable is that it may well be the only machine that is actually making use of resonance and in particular a Bessel dropout in order to change its operating mode. This is why there is no information available anywhere on a Bessel null in rotating machinery. What I am being asked to do is essentially write a white paper just to appease this forum! If I am going to go to all that trouble I assure you it will be published somewhere other than here! I can see no point in continuing this discussion as this forum does nothing but heap abuse on anyone who offers up a reasonable explanation that happens to be in conflict with DDWFTTW, which is itself unproven!
As far as “faster than the turntable” is concerned; yes I believe that is happening after the mode change which comes about by the Bessel function. This happens only because of the resonance between the rotating parts on the cart and the rotating TT or treadmill. This cannot and will not happen when the cart is running on the ground. That should be self evident; you do not see the cart first going upwind, entering into resonance and then reversing direction! There is no equivalence between frames when you consider the rotating parts of the system. Yes, the Earth is rotating on its axis and yes theoretically the cart does push on the Earth some calculable but immeasurable amount, but it would be insane to think the cart can cause a mutual resonance with the earth! With this understanding of how the cart behaves on the TT and on the treadmill, it should be self-evident that NO similar behavior is achievable on the ground. This should be the END of all claims for DDWFTTW! On the bright side, this opens up an entirely new field of study in machinery mode changes due to resonance and Bessel dropout! There may very well be practical applications for this, although I have not yet thought of any.

 

[cesiumfrog]

What is intriguing about the cart and turntable is that it may well be the only machine that is actually making use of resonance and in particular a Bessel dropout in order to change its operating mode. This is why there is no information available anywhere on a Bessel null in rotating machinery.

I agree that in principle those concepts may be applicable to mechanical systems.

Schroder, you described the 2.4 value as proof beyond reasonable doubt. Hypothetically, what would it take to disprove your hypothesis? For example, by running the demonstration longer so that the 2.4 value could be measured to much higher precision, would this be a test of the heterodyne model? If we are able to make the turntable cart still go "DDWFTTW" but at a slower rate (by tying on a friction block) as well as at an even faster rate (by optimising the fan blades), so as to disagree with any Bessel null, would that falsify your explanation?

If the outdoor (cart on road in wind) videos turned out not to be hoaxes (and to be independently repeatable under controlled conditions) would that falsify your claim (that DDWFTTW is impossible) or would you say that it proves DDWFTTW actually is possible thanks to heterodyne propulsion?

 

[ThinAirDesign]

I can see no point in continuing this discussion as this forum does nothing but heap abuse on anyone who offers up a reasonable explanation that happens to be in conflict with DDWFTTW, which is itself unproven!

There are two problems with your above *assertions* (bolded):

A: an explanation is only "reasonable" if it fits the actual behaviors -- yours doesn't as described below.
B: DDWFTTW has been proven in all venues, repeatedly and independently.

As far as “faster than the turntable” is concerned; yes I believe that is happening after the mode change which comes about by the Bessel function. This happens only because of the resonance between the rotating parts on the cart and the rotating TT or treadmill.

This assertion, in spite of the fact that no matter the resonance of the various devices and environments, the results are *always the same* -- DDWFTTW. If this "mechanical heterodyne" were so darn special as to be unexplored, it would take more than random interaction to be 100% successful.

This cannot and will not happen when the cart is running on the ground.

Well, of course since the cart *actually does* go DDWFTTW when running on the ground as independently verified by multiple parties, this sort of puts a bit of a damper on your assertions.

That should be self evident; you do not see the cart first going upwind, entering into resonance and then reversing direction!

It is self evident -- you don't see that behavior from the cart on *any* of the venues where it's been tested ... not the turntable, not the treadmill, not the street. Every single test, every single time, every single venue, every single test device -- DDW without "first going upwind, entering into resonance and then reversing direction!" This *alone* blows your theory to smithereens.

Yes, the Earth is rotating on its axis and yes theoretically the cart does push on the Earth some calculable but immeasurable amount, but it would be insane to think the cart can cause a mutual resonance with the earth!

Yes it would insane -- just as it would be insane to think that every single DDWFTTW device, with their various weights and resonances would cause this "mutual resonance" with every single turntable and treadmill given their also various weights and resonances.

With this understanding of how the cart behaves on the TT and on the treadmill, it should be self-evident that NO similar behavior is achievable on the ground.

Yes, of course ... except your "understanding" isn't.

This should be the END of all claims for DDWFTTW!

And it just might be if not for that little niggling, leftover, unexplained (by you) issue of device after device going DDWFTTW upon demand.

I predict you're going to be a very hard man to find once some better documented cases of DDWFTTW on the street pop up -- MythBusters, etc.

JB

 

[swerdna]

If we are able to make the turntable cart still go "DDWFTTW" but at a slower rate (by tying on a friction block) as well as at an even faster rate (by optimising the fan blades), so as to disagree with any Bessel null, would that falsify your explanation?

You mean like this? - http://www.youtube.com/watch?v=VgaXpHOxtQg&feature=related

 

[ThinAirDesign]

You mean like this? - http://www.youtube.com/watch?v=VgaXpHOxtQg&feature=related

A video which shows a DDWFTTW device moving at ~1.03x the wind speed steady state.

JB

 

[ThinAirDesign]

Or this one:

... where the cart goes for ~2 minutes within ~1% of windspeed.

JB

 

[Subductionzon]

You mean like this? - http://www.youtube.com/watch?v=VgaXpHOxtQg&feature=related

A mouse in a block invokes a 3rd degree Besel nut that is resolved at 1.05 further proof that it is an unharmonius reaction to the turntable playing Mozart instead of Black Sabbath.

 

[Subductionzon]

Or this one:

... where the cart goes for ~2 minutes within ~1% of windspeed.

JB

Shame on you JB you know that the cart is hovering (ala humber) to the heterodyned tunes of Surf City Here We Come by the Beach Boys, and Wipeout by I forgot who. Obvious proof of diheterodynamicism.

 

[ThinAirDesign]

Do you think the cart will speed up if we play "Wipeout"?

JB

 

[Subductionzon]

Your best bet is to play either l"Little Deuce Coupe" or "Fun, Fun, Fun".

 

[rcgldr]

Before this thread goes downhill, note that swerdna is planning to make either an air or water based outdoor device, and I'd like to see that posted in this thread.

 

[vanesch]

This is why there is no information available anywhere on a Bessel null in rotating machinery. What I am being asked to do is essentially write a white paper just to appease this forum! If I am going to go to all that trouble I assure you it will be published somewhere other than here!

But you are most welcome to do so! We encourage publication in peer-reviewed literature.
The point is that if there are no sources out there and if it would take you a paper to write up this NEW material, then it is evident that this is not an "obvious and well-known" material, and it might just not stand up to scrutiny.

In fact, we are not talking about any "vibrations", or "resonance modes" or all that - concepts which are well-known to most people having studied some mechanics. Bessel functions do appear in several of these problems. They appear for instance often when a Poisson equation is solved in something with a cylindrical symmetry. They also appear in frequency modulation. Yes, Bessel functions do appear in mechanical problems and in radio-engineering. But it is not because they do appear in some specific problems, that there is an evident (or even hidden) relationship between them and the simple problem of relative motion and a non-slipping wheel.

Because you are trying to wiggle out of the mess you talked yourself in:

- you claimed (post 755):

As seen from the observer on the ground, the cart is going 2 mph to the left, the treadmill is going 10 mph to the right. Do you dispute that the velocity of the cart wrt the treadmill is 12 mph ?
Do you dispute that the air is doing 10 mph wrt the treadmill ?

and you answered:

I DO dispute that "the velocity of the cart wrt the treadmill is 12 mph". I dispute that loud and clear! You are making a linear addition when this is clearly a heterodyne problem. Can you not recognize a heterodyne when you see it? The heterodyne which is the 2 mph is the Difference between the velocity of the tread and the velocity of the cart. The velocity of the cart is 8 mph much less than the tread and much less than the wind. Do you dispute that this is a heterodyne?

This was in reaction to your post 752, which was a similar gem:

I AM saying that the cart with respect to the tread, is going SLOWER than the tread with respect to the air! Is that clear enough for you to understand?

Or even better, your post 760, concerning the condition of a non-slipping wheel:

Here, it is obvious that you do not understand a simple heterodyne problem. The velocity at the point of contact with the wheel is NOT “of course exactly the same as the velocity of the tread”. If it were always exactly the same as the velocity of the tread, the wheel could neither advance or retard. The velocity must change! The tread velocity is constant, so only the velocity of the rim of the wheel changes; the rpm of the wheel changes! For a translation of the axle in the direction opposite to the direction of the tread, the rpm of the wheel must slow down! The rpm slows, the linear velocity at the wheel rim slows, and more tread passes the point under the axle than circumference of wheel does. That results in a translation to the left, in the opposite direction to the tread. This is basic mechanics, Vanesch and you cannot deny it any more!

Followed by what you wrote in post 778 (concerning the trivial relationship between the rotation velocity of a non-slipping wheel on a moving surface).

THESE are the aberrant claims that you should explain, with all the Bessel functions in the world. Not by spouting a few words.

 

[mheslep]

891 posts in three weeks! Marathons posts of 20 hours straight? Has there ever been anything like this on PF? I wonder if there is a way to display the stats.

 

[spork]

It's amazing, but this seems to be the natural cycle of things. It seems pretty common now - many people come to understand and accept DDWFTTW, some quietly go away, and one person remains to be the poster boy for wrongness for 100's or even 1000's of posts.

 

[vanesch]

891 posts in three weeks! Marathons posts of 20 hours straight? Has there ever been anything like this on PF? I wonder if there is a way to display the stats.

We try to keep it going, but I have to admit that there are great actors in the play!

 

[schroder]

I agree that in principle those concepts may be applicable to mechanical systems.

Schroder, you described the 2.4 value as proof beyond reasonable doubt. Hypothetically, what would it take to disprove your hypothesis? For example, by running the demonstration longer so that the 2.4 value could be measured to much higher precision, would this be a test of the heterodyne model? If we are able to make the turntable cart still go "DDWFTTW" but at a slower rate (by tying on a friction block) as well as at an even faster rate (by optimising the fan blades), so as to disagree with any Bessel null, would that falsify your explanation?

If the outdoor (cart on road in wind) videos turned out not to be hoaxes (and to be independently repeatable under controlled conditions) would that falsify your claim (that DDWFTTW is impossible) or would you say that it proves DDWFTTW actually is possible thanks to heterodyne propulsion?

The reason why I find the turntable so interesting is that it would allow for experiments to test the type of things you have mentioned. I don’t think tying on a friction block would detune the resonance but it would flatten out the response resulting in a slower CCW rotation. I am now very seriously considering building my own TT but it will have all the bells and whistles required to do detailed experiments. I will have at least three tachometers, one on the TT, one on the rotating crossarm, and one on the wheel. It will also have at least one accelerometer and a LeCroy oscilloscope to display both rotational speed and resonance as time functions as well as displaying a fast Fourier transform of the resonance signal. I think the blade passage frequency of the propeller must also be monitored. I find this far more interesting than the pedantic claim of DDWFTTW.
I know of NO outdoor test which shows the cart going directly downwind faster than the wind. Obviously, it can go downwind, but so can any wind-blown debris, and in fact, in at least one video, the debris is going faster than the cart!
As much as I appreciate your interest in this, as anyone can see, this thread has degenerated into personal attacks so as to distract from the contradictions to the DDW claim and it really serves no purpose for me to continue here. Maybe I will start a new thread devoted to mechanical resonance but that remains to be seen. Besides the attacks you see here in the thread, I have received particularly virulent attacks via pms, from no less than another “pf mentor”. There is only so much that I am prepared to put up with.

 

[spork]

I don’t think tying on a friction block would detune the resonance but it would flatten out the response resulting in a slower CCW rotation.

I assume you realize everyone knows this is absolute nonsense - right?

I am now very seriously considering building my own TT but it will have all the bells and whistles required to do detailed experiments. I will have at least three tachometers, one on the TT, one on the rotating crossarm, and one on the wheel. It will also have at least one accelerometer and a LeCroy oscilloscope to display both rotational speed and resonance as time functions as well as displaying a fast Fourier transform of the resonance signal. I think the blade passage frequency of the propeller must also be monitored.

You'll do none of that.

I know of NO outdoor test which shows the cart going directly downwind faster than the wind.

So you're saying you know all this really nifty physics stuff and you can't understand this simple toy that goes downwind faster than the wind!?

in at least one video, the debris is going faster than the cart!

Yup. I made that video. I'd be happy to explain it, but I find there are two kinds of people in the world... those that need no explanation, and those for whom no explanation will do.

as anyone can see, this thread has degenerated into personal attacks so as to distract from the contradictions to the DDW claim

There is no "contradiction" to the DDW claim. It's been proven experimentally and analytically.

and it really serves no purpose for me to continue here.

On the contrary. This thread exists expressly for you and because of you. Without you it would simply be a bunch of people that understand the physics behind this thing, and have nothing left to talk or debate about.

Maybe I will start a new thread devoted to mechanical resonance

No you won't.

Besides the attacks you see here in the thread, I have received particularly virulent attacks via pms, from no less than another “pf mentor”.

No you haven't.

There is only so much that I am prepared to put up with.

No there's not.

 

[vanesch]

I am now very seriously considering building my own TT but it will have all the bells and whistles required to do detailed experiments. I will have at least three tachometers, one on the TT, one on the rotating crossarm, and one on the wheel.

Brilliant. I make a strong prediction. If T1 is the tachymeter (giving the number of rotations per second of the table) of the TT, T2 is the tachymeter on the arm (giving the number of rotations per second) and T3 is the tachymeter on the wheel of the cart (giving the number of rotations per second), then, if the radius of the track on which the wheel is running on the table is R, and the radius of the wheel is r, and the wheel doesn't slip, then I predict:

T3 = R/r * (T1 - T2)

The above formula is valid for all motions if T1 and T2 are *signed* tachymeters, that is if they give you a positive number if their object turns CCW, and a negative number if their object turns CW. (or vice versa)

If the tachymeters just give absolute values and no sign indication of the sense of rotation, then we have to use the above formula if both TT and arm turn in the same direction (CW or CCW), and we have to use:

T3 = R/r * (T1 + T2) if the table is going CW and the arm CCW, or vice versa.

The sign of T3 depends on which side the tachymeter is mounted on it and if it is a signed tachymeter.

I make the above prediction without any comprehension of the zeros of Bessel functions in the Superheterodyne Class A Reboosted Overdriven Dolby Surround theory of rotating tables, but just based upon the defining property of non-slipping wheels, that the point of contact has the same velocity on both sides of the contact, and the earlier given formula which you disputed.

Let experiment decide

EDIT:

Just to be more explicit, in post 762, I wrote amongst other things:

Second application:
Now, if the wheel is not on a road, but on a treadmill that GOES TO THE RIGHT with a velocity v_tread (positive number: the velocity vector of a point on the treadmill is (v_tread,0) and this is a vector oriented to the positive X-axis, so to the right), then, if the wheel is making a NON SLIPPING CONTACT, we see that the point at the bottom of the wheel is having the same velocity as the tread (as it isn't slipping there and in contact), so we have equality of the two velocity vectors:

( + w R + vx, vy) = (v_tread,0)

from which:
w R + vx = v_tread and vy = 0

In other words: w = (v_tread - vx) / R.
and no vertical motion.

here w was the angular velocity of the wheel, vx was the velocity of translation of the cart, and v_tread was the velocity of the surface, both velocities in the same direction of course. R was the radius of the wheel, which is now to be called "r".

So, we take this expression to be w = (v_table - v_cart) / r

Now, if we take this direction to be "right to left" on the turntable(*), when the cart is nearby the observer, then we have:

v_table is (2 Pi R T1) (circumference of the track, times the number of times this table turns per second)

v_cart is (2 Pi R T2) (circumference of the track, times the number of times the arm (and hence the cart) turns per second)

w is 2 Pi T3 because 1 turn per second (unit of T3) comes down to 2 Pi radians per second.

So we fill in: 2 Pi T3 = ( (2 Pi R T1) - (2 Pi R T2)) / r

We can bring out 2 Pi R of the numerator of the fraction on the left side:

2 Pi T3 = 2 Pi R (T1 - T2) / r

We can divide by 2 Pi (2 Pi is not zero) on both sides of the equality:

T3 = R (T1 - T2) / r

We can change the order of the factors in a product (commutativity of x in R,+,x) :

T3 = R / r (T1 - T2)Tada Tadaaaa !



(*) Just to be completely clear: I just flipped the positive orientation of the X-axis, which was "left-to-right" in post 762, and which I now take "right-to-left" in this post, to be in agreement with the videos and all the conventions others have used up to now. The formula remains of course just as valid, except that w will now be positive in the CCW direction (we look upon the picture now from the other side).

 

[spork]

Brilliant. I make a strong prediction.
...
Let experiment decide

You are one seriously optimistic dude! First of all, he won't be making any turntables, or running any tests. Secondly, if someone else ran exactly the tests described, and got exactly the results you predict, he could easily explain how you're still wrong, and how you don't see the obvious reason for the observed outcome.

 

[vanesch]

You are one seriously optimistic dude!

That's me

First of all, he won't be making any turntables, or running any tests.

I hope he will. Maybe the motivation to show us wrong will be strong enough. After all, I would be seriously embarrassed, not to say, stand out as an arrogant, ignorant moron if his experiment turns out not to be in my favor ! I'm playing my reputation here. I'm putting my head out. Bait ! Bait !

Actually, the experiment would be in any case useful, as some of us will hopefully finally learn something (a bit the hard way).

Secondly, if someone else ran exactly the tests described, and got exactly the results you predict, he could easily explain how you're still wrong, and how you don't see the obvious reason for the observed outcome.

Mmm. Maybe. You mean, like: http://theflatEarth'society.org/ (?)

(the above link is not to be taken very seriously - for the humour-impaired...)

 

[ThinAirDesign]

I don’t think tying on a friction block would detune the resonance but it would flatten out the response resulting in a slower CCW rotation.

Meaning the device goes DDWFTTW slower than it would were it not dragging the block.

I am now very seriously considering building my own TT but it will have all the bells and whistles required to do detailed experiments.

Excellent -- the results of which are not hard to predict for those of us who understand the basic laws of physics and principle involved. For the record, I'm on board with vanesch's predictions above but I'll add one: Things will also vibrate -- and all the changes in the world to the components to change their resonance will not alter the outputs of the tachometers as long as you keep the wheel as firmly in contact with the ground as we do.

I find this far more interesting than the pedantic claim of DDWFTTW.

Everyone has to focus on the things they can understand ... I get it.

I know of NO outdoor test which shows the cart going directly downwind faster than the wind.

Considering your "heterodyne" position and your absolute inability to accept centuries old principles of physics, I certainly understand your skepticism regarding the documentation quality of the outdoor videos. Unfortunately for you and your blustering statements, these carts DO go DDWFTTW outdoors and eventually the money will be spent to produce said documention. It's very easy to see this happen in person but it's also very difficult to produce a YouTube video that answers even reasonable critics concerns outdoors.

As previously stated, you're going to be a very hard man to find when this documentation is released as the results just leave you standing unshielded from your own ignorance and arrogance.

... and in fact, in at least one video, the debris is going faster than the cart!

LOL ... Yeah, that's what happens in the first few seconds before the cart gets up to wind speed.

Most folks just sort of intuitively understand that a device doesn't accelerate from a total stop to windspeed *instantly*, and during that initial acceleration period the wind is going faster than the device. You on the other hand seem to revel in your inability to grasp such.

There is only so much that I am prepared to put up with.

Yeah Cristoph -- that's why you went over and started your routine on the JREF forum. LOL

JB

 

[ThinAirDesign]

shroder ... don't you want to stick around for the results of the test you yourself specifically suggested?

Sail-cart VS prop-cart?

You're going to just LOVE the results. LOL

JB

 

[ThinAirDesign]

Had a chat with spork this morning and he pointed out something quite interesting:

According to schroder's theory, the cart *will* go DDWFTTW on the treadmill and turntable but can't do the same on the surface of the Earth because can't interact with the Earth's mass in the desired way.

Well, if that were true (and it's not), DDWFTTW is still proven just with the treadmill tests: To go DDWFTTW outside, simply stretch a mile long treadmill belt out across the dry lake bed and suspend it with the same bed supports that are under the small treadmill. Now rather than move the belt, just set the cart on the belt and wait for the wind blow it DDWFTTW. The cart and the belt are now able to interact in the very same way, setting up the "heterodyne" and propelling the device. If the belt need to shake somehow ... fine, use the same wind that's blowing to shake the belt.

Or, to replicate the TT, lay a strip of plywood out and suspend it in a manner that emulates the way the TT is supported.

So, even if schroder were correct in his "it's the vibrations that make it possible" (and he's not), there's absolutely no reason to believe that the special interactive conditions can't be replicated outdoors or that DDWFTTW has not actually already been demonstrated.

Of course it's easier to just set the car down on the street and let it run DDWFTTW, but that will *never* work, now will it. ;-)

JB

 

[cesiumfrog]

I know of NO outdoor test which shows the cart going directly downwind faster than the wind. Obviously, it can go downwind, but so can any wind-blown debris, and in fact, in at least one video, the debris is going faster than the cart!
As much as I appreciate your interest in this, as anyone can see, this thread has degenerated into personal attacks so as to distract from the contradictions to the DDW claim [..] particularly virulent attacks via pms, from no less than another “pf mentor”.

Schroder, thank-you for making this thread so lively, and I hope the name-calling will be retracted or otherwise dealt with.

May I ask, how did you originally know that DDWFTTW would be impossible? (I must admit, even though I am studying for my third physics degree, it wasn't obvious to me that any particular physical laws are contradicted by such devices.) I was also wondering, do you agree with Einstein (http://www.physclips.unsw.edu.au/jw/sailing.html" ) that sail boats can tack diagonally across the wind in such a way that their velocity made good (that is, the component going directly downwind) exceeds the wind speed (even though the boat itself obviously cannot go DDWFTTW)?

simply stretch a mile long treadmill belt out across the dry lake bed and suspend it with the same bed supports that are under the small treadmill. Now rather than move the belt, just set the cart on the belt and wait for the wind blow it DDWFTTW. The cart and the belt are now able to interact in the very same way, setting up the "heterodyne" and propelling the device. If the belt need to shake somehow ... fine, use the same wind that's blowing to shake the belt.

A skeptic might liken that to a bullet train powered by a stationary wind farm. Alas, I think this could only be settled if we had multiple independent demonstrations of outdoor carts on level ground and with some kind of windsock or other means to track the wind.

 

[ThinAirDesign]

Schroder, thank-you for making this thread so lively, and I hope the name-calling will be retracted or otherwise dealt with.

You mean schroder's name calling, or the others. LOL

Schroder loves to throw out lots of insults, but he really doesn't want to see them thrown back.

JB

 

[ThinAirDesign]

Alas, I think this could only be settled if we had multiple independent demonstrations of outdoor carts on level ground and with some kind of windsock or other means to track the wind.

Well, for those that understand the basic physics involved, it's been done to death and it's settled. There are of course plenty of people around who for various reasons would love to see a well documented outdoor test. I happen to be one of those.

It will happen and the results are predictable: the cart behaves the same on the street as on the turntable and treadmill and goes DDWFTTW repeatably.

JB

 

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I think this could only be settled if we had multiple independent demonstrations of outdoor carts on level ground and with some kind of windsock or other means to track the wind.

Yes, either that or simply accept that the principle of equivalency of inertial frames still works and test them on a treadmill. OR we could note, as you did, that ice-boats can achieve downwind VMG of 3X to 4X true wind speed, and note that two such boats tacking side-by-side and attached by a telescoping pole resolves the issue. OR we could just accept the straightforward analysis as we accept that 2 + 2 = 4

 

[uart]

Schroder, thank-you for making this thread so lively, and I hope the name-calling will be retracted or otherwise dealt with.

May I ask, how did you originally know that DDWFTTW would be impossible? (

Hi Cesium, that's the thing that has been so annoying about Schroder in this discussion. I think he just assumed that it's impossible at the outset and from then on his mind seemed to slam shut like a steel trap. In this present state of denial he'll say (or believe) just about anything, no matter how silly, in order to keep denying it. I mean seriously just look at some of the claims he's made in so far in this thread. Like the one that if the cart moves 2 m/s from left to right and the tread moves 10 m/s from right to left that the relative velocity between the two is less that 10 m/s. He maintained that stance for ages, and that's just one example. In his present state I think he'd believe that 1+1=3 or that black=white if it was necessary to keep up the denial.

 

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In his present state I think he'd believe that 1+1=3 or that black=white if it was necessary to keep up the denial.

Pretty standard stuff. I can point you to other forums where we have one guy that will say ANYTHING to continue denying the reality before him.

 

[uart]

Pretty standard stuff. I can point you to other forums where we have one guy that will say ANYTHING to continue denying the reality before him.

Yeah it's amazing how this dwfttw thing can have that effect on people who otherwise seem reasonably intelligent. As I say the best explanation I can think of is the "mind shutting up like a steel trap" and going into a state of denial, you could almost say delusional. Perhaps Psychologists could be of more help to Schroder than Physicists at this point.

 

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Perhaps Psychologists could be of more help to Schroder than Physicists at this point.

Unfortunately, psychologists cannot prescribe meds.