Merged DDWFTTW in a “Real” Wind

[humber]

what bit?

Nevermind. It really does not matter under those circumstances does it?
Maybe evidence for a sail cart, but not ddw.
The wind before the peak changes 20 degrees, and then back again, while the overall trend is from +100 to -100?

Ludicrous, but it was your choice not mine, and there are problems with the record run data, and that is more significant.

 

[69dodge]

If we start from zero, and add energy requirements, we need to add the energy required to overcome rolling resistance and air resistance and chain friction. And also the energy required to spin the propeller. But if we start with the (156 N)(9 m/s) = 1404 J of work done on the cart per second, we need to subtract the energy required to spin the propeller. This must mean that somehow the 1404 J counts that energy twice!

Yes, it does. Once as part of the 156 N force on the cart, and once as part of the 9 m/s speed of the cart.

The propeller is hard to spin. It's connected to the wheels rolling on the ground in such a way that moving the cart forward spins it. This makes the cart hard to push forward. This difficulty constitutes part of the 156 N force applied to the cart via the propeller. The air exerts this part of the 156 N on the propeller, while moving at 5.9 m/s, thus providing the power to spin the propeller.

Why is the propeller hard to spin? Because causing it to spin in air pushes the cart forward relative to the air. So, the power required to move the cart at its 3.1 m/s speed relative to the air is already provided for, as it's identical to the power required to spin the propeller. The (156 N)(3.1 m/s) power is not additional to the (156 N)(5.9 m/s) power; it's part of it.

Therefore, the 1404 W = (156 N)(3.1 m/s + 5.9 m/s) counts it twice.

 

[Llyricist]

For the hell of it:

Blue = Run 1 (Record Run)
Green = Run 2
Yellow = Run 3
Cyan = Run 4
Red = Run 5
Magenta = Run 6
Orange = Run 7
Black = Run 8

Anyone want the kml files?

 

[humber]

For the hell of it:

[qimg]http://www.internationalskeptics.com/forums/attachment.php?attachmentid=22167&stc=1&d=1305354342[/qimg]

Blue = Run 1 (Record Run)
Green = Run 2
Yellow = Run 3
Cyan = Run 4
Red = Run 5
Magenta = Run 6
Orange = Run 7
Black = Run 8

Anyone want the kml files?

Errr...doh. I told Yevgheni that you would get help from Spork. Rather too quick in finding those 8 runs.
Why do you think that adds anything to the matter other than to show the cart keeps the same heading? Or to show that it may be a wind funnel?
On the other hand, you don't get to re-average the data, because you have no idea what you are doing. The data is supplied as is, and that it that.

 

[drewid]

You think it's OK for the GPS heading calculation, to output instant changes of 350 degrees, because it is slowing. Is that right?

At very low speeds, yes, obviously.

 

[humber]

At very low speeds, yes, obviously.

No it isn't. But that is connected to another matter, I will take up with NALSA.

 

[tobermoryphil]

No it isn't. But that is connected to another matter, I will take up with NALSA.

NALSA must be quaking in their boots by now!

 

[humber]

NALSA must be quaking in their boots by now!

Oh, they will understand what that change means.

But the chart is a "record" based on the bit inside the red square, where there is less change in a wind that is changing by 100 degrees? What would that be then? Currents mixing or passing? Or does the wind stop, pause for a think, and then change direction? Not relevant.

 

[profpangloss]

That's mistake number one, but that's for the report.
The wind changes by 100 degrees and the cart does not, so not at all ddw.

The other is not to notice the connection between the vane the calculated GPS heading.

If the wind was varying by 100 degrees, and the cart was holding a steady course, how in the world can anyone make a claim of DDWFTTW? How can anyone take such a claim seriously? The other issue I see is the wind velocity was being measured at an anemometer stationed quite some distance away from the cart wasn’t it? How can anyone say the wind velocity at the cart’s location was the same as that being measured at the location of the anemometer? I think it is certainly possible for the wind to be gusting at over 20 mph at the cart while being 10 mph where the measurement is being taken. Besides, we can see from some of the data posted here that the wind was well over 20 mph for some of the runs, so such a gust happening at the cart is not out of the question.

If there was some mathematical support for DDWFTTW, I might not be so critical of the field data, but the math indicates to me that DDWFTTW is not possible. In particular, nobody has made any reasonable objection to my math that shows that conservation of energy would be violated. The objections that the earth should take up some of the momentum and energy are entirely wrong, since I am using the frame of reference where the earth is stationary. It cannot have any momentum or energy in this frame, only the cart and the wind are moving and both energy and momentum must be conserved in this frame. I have shown that energy is not conserved!

 

[profpangloss]

At very low speeds, yes, obviously.

I believe with today's best commercial GPS, static navigation errors due to slow speeds are only significant under 1 mph. Even at a decent walking speed, the dynamic navigation is very accurate, so this should not have been a problem with the cart slowing down, in my opinion.

 

[humber]

If the wind was varying by 100 degrees, and the cart was holding a steady course, how in the world can anyone make a claim of DDWFTTW? How can anyone take such a claim seriously? The other issue I see is the wind velocity was being measured at an anemometer stationed quite some distance away from the cart wasn’t it? How can anyone say the wind velocity at the cart’s location was the same as that being measured at the location of the anemometer? I think it is certainly possible for the wind to be gusting at over 20 mph at the cart while being 10 mph where the measurement is being taken. Besides, we can see from some of the data posted here that the wind was well over 20 mph for some of the runs, so such a gust happening at the cart is not out of the question.

It is a ludicrous claim. There are many measurement problems with vane including stalling, and the influence of the constant acceleration.
The report does suggest that the anemometer on the CV was used, but I think a reference elsewhere said it was the remote. But, even on the CV is it too slow to track gusts under the influence of the apparent wind.
Both the vane and the anemometer are for fixed use.

The cart either brakes or comes to the end of a run when the wind suddenly changes, is pushed...waits it out....all sorts of biases.

 

[humber]

I believe with today's best commercial GPS, static navigation errors due to slow speeds are only significant under 1 mph. Even at a decent walking spped, the dynamic navigation is very accurate, so this should not have been a problem with the cart slowing down, in my opinion.

The output of the CV direction calculation is used to calculate the true wind, which then changes up and down, and that biases the averaging filter at the start and end of runs.
A great deal of the data is simply that happening as the cart stands still.
That run above, is another record run, and not "the record run". Apparently if you squint through the gaps between the heading noise, there are 8 in total.

 

[profpangloss]

It is a ludicrous claim. There are many measurement problems with vane including stalling, and the influence of the constant acceleration.
The report does suggest that the anemometer on the CV was used, but I think a reference elsewhere said it was the remote. But, even on the CV is it too slow to track gusts under the influence of the apparent wind.
Both the vane and the anemometer are for fixed use.

The cart either brakes or comes to the end of a run when the wind suddenly changes, is pushed...waits it out....all sorts of biases.

Well, I read most of the information on the NALSA site and I came away with the impression there was supposed to be a specific course the cart was to run, and it must leave that course faster than it entered. From what you are saying, I gather they simply let the cart run where and when it suited them, and if they found a spot in the resulting data that seemed to indicate DDWFTTW was achieved, they declared that was the course! If that is indeed the case, this is a lot of nonsense, isn't it?

 

[profpangloss]

The output of the CV direction calculation is used to calculate the true wind, which then changes up and down, and that biases the averaging filter at the start and end of runs.
A great deal of the data is simply that happening as the cart stands still.
That run above, is another record run, and not "the record run". Apparently if you squint through the gaps between the heading noise, there are 8 in total.

I'm not understanding this. If a lot of the data is just noise while the cart was standing still, you just throw that out, right? Or are you saying this data being taken while the cart is standing still sets up a bias that has an effect on the data taken while the cart is moving? Obviously, I don't understand!

 

[drewid]

I believe with today's best commercial GPS, static navigation errors due to slow speeds are only significant under 1 mph. Even at a decent walking speed, the dynamic navigation is very accurate, so this should not have been a problem with the cart slowing down, in my opinion.

That's for processed _averaged_ data, not the raw data.

I'm not understanding this. If a lot of the data is just noise while the cart was standing still, you just throw that out, right? Or are you saying this data being taken while the cart is standing still sets up a bias that has an effect on the data taken while the cart is moving? Obviously, I don't understand!

This is the bit that Humber doesn't get.

 

[69dodge]

The objections that the earth should take up some of the momentum and energy are entirely wrong, since I am using the frame of reference where the earth is stationary.

Not energy, at least not any important amount, just momentum.

You cannot choose absolutely any frame of reference that you like, if you want to use Newton's laws of motion in their usual form. You can choose any inertial frame of reference.

You can choose a frame of reference in which the Earth is initially stationary, but if the Earth's momentum changes, as it will in response to forces on the Earth, you cannot choose a frame of reference in which the Earth remains stationary, because that frame of reference is not inertial.

Conservation of momentum does not hold in non-inertial frames of reference.

As Subduction Zone pointed out, your argument would imply, not only that the Blackbird cannot work, but also that no car can work. When a car accelerates, its momentum changes. Where is the corresponding oppositely-directed change, to satisfy conservation of momentum? It is in fact in the momentum of the Earth, massive though it is. Its large mass implies a small velocity change, but not a small momentum change. The change in momentum of the Earth equals the change in momentum of the car, just in the opposite direction.

Also see this post of mine, which perhaps you missed in all the irrelevancy that goes on in this thread.

 

[humber]

Well, I read most of the information on the NALSA site and I came away with the impression there was supposed to be a specific course the cart was to run, and it must leave that course faster than it entered. From what you are saying, I gather they simply let the cart run where and when it suited them, and if they found a spot in the resulting data that seemed to indicate DDWFTTW was achieved, they declared that was the course! If that is indeed the case, this is a lot of nonsense, isn't it?

From the run, a 10 sec window can be selected, which must meet certain requirements such as a difference of 0.2 mph in the entry and exist speeds, and within 10 degrees of ddw. The speed in the middle is the record. The rest of the run is also to be within 10 degrees, but isn't.

 

[humber]

I'm not understanding this. If a lot of the data is just noise while the cart was standing still, you just throw that out, right? Or are you saying this data being taken while the cart is standing still sets up a bias that has an effect on the data taken while the cart is moving? Obviously, I don't understand!

In short, yes.
Much of the data is corrupted by that noise so there is no useful data for that period, and it influences the 10 second average of the true wind. But I would rather keep that last topic off the forum until I hear from NALSA, thanks.

Whatever the influence on the average, the + 50 degrees seems to emerge from the noise, and that noise extends back to where it comes in at - 50 degrees. In this case, it may be that the wind does change that much, which makes on wonder what control there was, or both, that, and the noise from the GPS. There are cases of both. The GPS low speed noise should have been filtered, or otherwise attenuated.

The 10 average wind direction is the other chart. There is a gap around where the runs is, or whatever.
It's not an record run, so I am not going to track down the details unless there is a good reason, but I think it is clear that the real data is in a haystack.

 

[spork]

It must be really frustrating to know that with all this super rigorous analysis resulting in an airtight case against our record, that no one at NALSA takes you seriously. In fact, it must be frustrating that no one anywhere takes you seriously (with the exception of harold and his many sock puppets).

Rather than dispute all this nonsense (as so many have successfully done here), I'll make a simple prediction... the record will stand. humber can make his own predictions, and they'll be as accurate as his prediction that we'd never take the cart to the lake bed, or that we'd never be allowed to run it, or all the many other predictions he's made about this.

 

[humber]

Rather than dispute all this nonsense

Ability permitting.

(as so many have successfully done here), I'll make a simple prediction... the record will stand. humber can make his own predictions, and they'll be as accurate as his prediction that we'd never take the cart to the lake bed, or that we'd never be allowed to run it, or all the many other predictions he's made about this.

Going to try and pull some strings?

You haven't a leg to stand on, and even if NALSA don't remove the record, not many will be convinced by the data, and that is NALSA's data.