Wind powered vehicle that goes downwind faster than the wind - Part 61 -

buttershug · 05-21-2016, 12:02 AM

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Ya know, looking at humber's post history at Physicsforums has me questioning whether or not he was actually a troll. He made five posts that don't appear to be insane, and then the cart thing happened, and suddenly all he could do was make batshit posts about that. It makes me wonder if he genuinely was (is?) just a guy who for whatever reason just can't seem to wrap his mind around the idea that motion is relative. Like that just broke his brain.

I honestly believe that he could not answer the following question;
"If your right hand if 12 inches away from your left hand, how far is your left hand away from your right hand?"

Heinz Hershold · 05-21-2016, 12:16 PM

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Exactly the sort of Cargo Cult mind set that Feynman was talking about!

Just like your complete lack of understanding of physics, you repeatedly display a complete lack of understanding of Feynman's comments about science. Case in point:

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If you’re doing an experiment, you should report everything that you think might make it invalid—not only what you think is right about it: other causes that could possibly explain your results.
Details that could throw doubt on your interpretation must be given, if you know them. You must do the best you can—if you know anything at all wrong, or possibly wrong—to explain it.

Note that Feynman did NOT say:

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If everything works -- if your experiments line up perfectly with your theory -- you STILL have the responsibility to take seriously the deluded rantings of cranks who demonstrably have no understanding of your subject matter, and you must do whatever extra experiments those cranks demand of you, even if the "reasons" they offer for the necessity of those extra experiments are demonstrably stupid. If you don't, then you're a poopyhead. Neener-neener.

But sure, keep misinterpreting Feynman. It adds to the comedy around here.

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Meanwhile, still no peer reviewed science here, just HORSESHIT.

"Peer review" appears to be yet another one of those things you don't understand.

I think you missed spork's point about Obama dropping a mic.

If he holds out a mic above the floor, such that there's nothing between the mic and the floor, and he lets it go: What happens? Well, of course it falls to the floor and hits the floor with an audible thump.

But you'll never find a single peer-reviewed paper with that conclusion. Does that make it horseshit? Of course not. The fact that the mic will fall to the floor when Obama drops it follows straightforwardly from established physics (putting aside for now the fact that it's also to be expected from ordinary everyday experience).

So it is here. Everyone who has actually studied physics, and has bothered to give the cart problem more than a couple minutes of serious thought, agrees that the ddwfttw cart should work, in principle at least, based on established physics -- just as surely as a dropped heavy object falls to the floor.

If someone writes up the theory of the cart and sends it to a physics journal, no qualified reviewer would ever say "This is horseshit; it violates CoE." Most reviewers would probably respond with "OF COURSE the cart works. It's obvious. There's nothing important enough here to publish."

Moreover, there's nothing magical about peer reviewed papers. Reviewers are people. But -- here's the crucial point -- reviewers are, or should be, people who have studied the subject matter in depth.

There are participants in this thread who have the very sort of qualifications that one would need in order to be asked to review a paper for a serious physics or engineering journal. And -- funny about that -- those of us with such qualifications all agree with spork, not with you.

That's peer review, just like the peer review that goes into publishing a paper.

So now, you even create your own crackpot version of *peer review*?

What crackpot lengths will you go to defend the Cargo Cult?

You are a JOKE!

Tell me, in what respected peer reviewed journal was anything published about ddwfttw?

The fact that you want to dodge peer review just confirms you are a crackpot.

But, for how much longer do you think you can continue to dodge the HFR video?

Heinz Hershold · 05-21-2016, 12:18 PM

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Heinz,

You are in luck, no HFR video needed to understand the cart, just look at your own explanation:

http://talkrational.org/showpost.php...&postcount=129

Here's Heinz diagram of the cart and TM belt viewed from the reference frame of the ground actually using the numbers from Heinz's math:

And here is Heinz's math with the values he computed consistent with the diagram:

There are two equations that relate propeller thrust with power and velocity of the air in the stream tube:

(1). Power = Thrust ( V + dv/2 )

(2). Thrust = Area x Density ( V + dv/2 ) dv

I will first consider the case of Static Thrust, where V = 0 and use Tobemoredulls 475 mm Propeller and 1 Watt of Power.
Area is 0.1772 m^2 , density = 1.225 kg/m^3, Then:

1 Watt = T ( dv/2) and T = 0.217 dv^2/2
2/0.1085 = dv^3
dv = 2.64 m/s

Static thrust = 0.757 N

With a dv of 2.64 m/s the kinetic energy given to the air when the cart is at
Wind speed = 1/2 mv^2 where the air mass is
Area x Density x dv/2 = 0.2865 kg
KE = 0.999 Watts

You can stop right there. The cart is in still air and stationary over the ACTUAL ground just like a Cessna starting to taxi so it meets the criteria for valid "static thrust". The Net thrust is positive and numerically is 0.757 -0.2 = .557 N. And this is a perfectly valid result which violates no rules as your calculation shows. There's absolutely nothing wrong with an object having an unbalanced force on it that can do work as long as there is a source of energy (the slowing of the wind over the surface from the frame of the belt, or supplied by the belt from the actual ground frame or windframe[either since they are the same]). If I initially placed your cart on the belt with a hand holding it in place, the prop will come up to speed and the forces as shown will be produced because all the criteria (for static thrust) is met. My hand will have to supply force to resist the excess thrust and when I release the cart, the net thrust excess will cause it to accelerate. It's required by the laws of physics! This is exactly what was shown in my "merciful end video" where the restraint was the 'force bar'. An excess thrust is produced and when released, the cart accelerates:

https://www.youtube.com/watch?v=lDDaw-ve7LY

See this video below at time tic 3:10 where the behavior is exactly what you are positing--developing static thrust by being restrained, upon release, accelerating with dynamic thrust (just like a Cessna develops static thrust with the brakes held, and then starts to taxi thus transitioning to dynamic thrust):

https://www.youtube.com/watch?v=uAbc323G8CA

Mathematically Confirming the conclusion from COE that the entire 1 Watt developed at the wheels Is used to accelerate the air through the disk, and the cart gains nothing{only as long as it's restrained, once released, it starts gaining KE and angular KE in the drivetrain which reduces the amount of energy going into just accelerating the air ( actual ground frame)} (that means: creates no energy thus complying with COE) The only energy for turning the prop comes from the wheels. The only energy that the system gets comes from slowing the air over the TM surface! And what is slowing the air is the thrust from the prop.

So now, since there is net thrust on the cart (which the cart is not allowed to just ignore like Heinz attempted

), the cart will start to accelerate and as it does, since it is now moving over actual ground and not in still air, we can no longer call it "static thrust", we have to call it "dynamic thrust". Since the excess Net Thrust is quite large, the cart will start to handily accelerate. And as it does, since the prop is turning very slightly faster but the air through the prop is just slightly faster, the dynamic thrust actually increases to a higher value than the static thrust at a lower RPM so the cart continues to accelerate. Which is exactly the behavior we observe in all videos when the cart is released and the TM speed is above V_minhover--the cart accelerates with experiment consistent with the math. By the way, if one wants to compute this "dynamic thrust" for some speed that is non zero over the actual ground (red line in diagram), of course the correct values to use are the cart's airspeed (or in this case, this also happens to be the speed over actual ground--not the speed the TM belt is moving. That would be absurd).

Also, as the cart starts to accelerate, the torque turning the shaft will be split between the rotational drag of the prop which is accelerating the air over ground, increasing the KE of the cart and the angular KE of the drivetrain because it is no longer operating steady state, but accelerating. It's worth noting that if the cart was operating with a constant prop speed, the thrust would steadily decrease as the cart is moving. But since the cart is fixed geared, as it moves up the belt, the prop turns faster and is able to increase its thrust from its former value as it accelerates. This goes on until the losses (which are mostly increasing as a square of the airspeed) increase until they equal the gains from slowing the air over the belt.

If the treadmill were really really long, it would accelerate until it reaches it's limit speed where the internal losses, prop drag, and turbulence losses equal the gains and it would travel up belt at a constant velocity. (Which is exactly what the Blackbird did at 2.8X windspeed of the day).

The cart is now proven by Heinz to work as advertised and no physics laws have been violated.

No need to look for any mysterious vibrations, magic elves, pixie dust or any other magic since they would only make the car work less efficiently (or at least differently) than the theory which explains the exact behavior seen in reality (within experimental measurement error)! The carteers are all in agreement with your excellent diagram, math, and explanation here! The only way to show that this theory isn't wrong is to find a counterexample that it doesn't explain, not look for pixie dust and unicorn answers. So, for any contender, show a real world physical example under carefully control conditions that meet all the criteria and yet doesn't behave properly. Until then, thanks for all the fish!

DDWFTTW all wrapped up in a tidy package and fully explained. QED.

The End.

Bye-Bye

Every Loose end I can think of mathematically shown, diagrammed, videos supplied, documented, and cleaned up (but maybe a bit redundant for emphasis)!

Adios!

A load of SHIT!

You violated COE again, now run away again.

Heinz Hershold · 05-21-2016, 12:30 PM

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Bottom Line is:

You cannot place a value of thrust on the diagram that is greater than the braking force, without violating COE.

End of story.

But the braking force is relative to the ground, while the thrust is relative to the air, which is moving relative to the ground.

That is not true.

Both forces are relative to the cart.

The braking force acts to slow the cart, while the thrust force acts to keep the cart moving.

With 1 Watt collected by the wheels at 5 m/s, the braking force is 0.2 N

If that entire 1 Watt is available to create a thrust force on the cart, at 5 m/s, the thrust force can be no greater than 0.2 N.

Anything more than that would violate COE.

If the thrust force is 0.5 N for example, at 5 m/s that is 2.5 Watts, with only 1 Watt input. That is not possible and violates COE.

You cannot isolate the thrust force to the air, as the crackpots are doing but first consider it as acting on the cart. That way, you make no mistake about COE and you can see that ddwfttw is not possible.

semper · 05-21-2016, 01:13 PM

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Bottom Line is:

You cannot place a value of thrust on the diagram that is greater than the braking force, without violating COE.

End of story.

But the braking force is relative to the ground, while the thrust is relative to the air, which is moving relative to the ground.

That is not true.

Both forces are relative to the cart.

The braking force acts to slow the cart, while the thrust force acts to keep the cart moving.

With 1 Watt collected by the wheels at 5 m/s, the braking force is 0.2 N

If that entire 1 Watt is available to create a thrust force on the cart, at 5 m/s, the thrust force can be no greater than 0.2 N.

Anything more than that would violate COE.

If the thrust force is 0.5 N for example, at 5 m/s that is 2.5 Watts, with only 1 Watt input. That is not possible and violates COE.

You cannot isolate the thrust force to the air, as the crackpots are doing but first consider it as acting on the cart. That way, you make no mistake about COE and you can see that ddwfttw is not possible.

Er, Heinzey, according to your theory of the forces and power calculation, since the forces must be analysed only relative to the cart, there is no velocity to compute. The thrust is doing no work, the wheel braking force is doing no work so there is no power transfer anywhere in the system.

Some may ask how, given there is no power transfer, the propeller can continue to rotate at steady rpm. But it appears to be the Heinz sentient wheel, and sentient propeller allowing for Heinz perpetual motion (HPM). This is your theory Heinz, you need to get it published in a peer reviewed journal before it can possibly be true, good luck with that.

Brother Daniel · 05-21-2016, 01:33 PM

Now Heinz conveniently forgets about the air's loss of energy (in the rest frame of the ground) or the ground's loss of energy (in the rest frame of the air).

He's tying himself up in knots trying to pretend the cart violates CoE, and can't even keep his own objections consistent.

Brother Daniel · 05-21-2016, 01:41 PM

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So now, you even create your own crackpot version of *peer review*?

I think you didn't read my post for comprehension. Try again.

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Tell me, in what respected peer reviewed journal was anything published about ddwfttw?

Tell me, in what respected peer reviewed journal was anything published about what happens to a mic when Obama drops it?

And yet it seems to me that if Obama drops a mic, it will fall, just like any other heavier-than-air object falls when released in the air.

The fact that it's specifically a mic doesn't matter. The fact that it's specifically Obama doesn't matter.

I guess that makes me a crackpot?

Heinz Hershold · 05-21-2016, 02:47 PM

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So now, you even create your own crackpot version of *peer review*?

I think you didn't read my post for comprehension. Try again.

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Tell me, in what respected peer reviewed journal was anything published about ddwfttw?

Tell me, in what respected peer reviewed journal was anything published about what happens to a mic when Obama drops it?

And yet it seems to me that if Obama drops a mic, it will fall, just like any other heavier-than-air object falls when released in the air.

The fact that it's specifically a mic doesn't matter. The fact that it's specifically Obama doesn't matter.

I guess that makes me a crackpot?

Really, you are looking more and more like a desperate crackpot every day, and with every post you make, and frankly you look silly.

The fact is, peer review has one specific meaning in science, and you cannot assign a different meaning to it just because you want to.

As far as dropping a microphone is concerned, countless peer reviewed papers have been written on the force and acceleration of gravity. Without all that work you would be as confused about the falling microphone as you are about the cart on the treadmill.

I repeat

Tell me, in what respected peer reviewed journal was anything published about ddwfttw?

Heinz Hershold · 05-21-2016, 02:49 PM

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Now Heinz conveniently forgets about the air's loss of energy (in the rest frame of the ground) or the ground's loss of energy (in the rest frame of the air).

He's tying himself up in knots trying to pretend the cart violates CoE, and can't even keep his own objections consistent.

And yet, you still cannot assign a value of thrust that is greater than the value of brake force without violating COE.

Heinz Hershold · 05-21-2016, 02:53 PM

There are two equations that relate propeller thrust with power and velocity of the air in the stream tube:
Power = Thrust ( V + dv/2 ) and Thrust = Area x Density ( V + dv/2 ) dv
I will first consider the case of Static Thrust, where V = 0 using a prop diameter of 475 mm
and 1 Watt of Power. Area is 0.1772 m^2 , density = 1.225 kg/m^3,
Then:
1 Watt = T ( dv/2) and T = 0.217 dv^2/2
2/0.1085 = dv^3
dv = 2.64 m/s
Static thrust = 0.757 N
The static thrust of 0.757 N only exists if the cart is stationary and the thrust is only doing work on the air. No work is being done to move the propeller or the cart.

Since work is being done to move the propeller on both the treadmill belt as well as the ground, the thrust is not static, but is at the dynamic level and cannot exceed 0.2 N without violating COE.
Using the same equations as before, but this time V = 5 m/s:
Power = Thrust ( V + dv/2 ) and Thrust = Area x Density ( V + dv/2 ) dv
1 Watt = T (5 + dv/2) and T = 0.217 (5 + dv/2) dv
2 / (10 + dv) = 1.085 dv + 0.1085 dv^2
2 = .1085 dv^3 + 2.17 dv^2 + 10.85 dv
dv = 0.178
Dynamic Thrust = 0.1965 N
Mathematically confirming the conclusion from COE that the Dynamic Thrust can never be greater than 0.2 N.

In fact, the calculated value of 0.1965 N means the cart cannot remain at wind speed even with 100% efficiency. It will never reach wind speed, or if pushed to wind speed and released, it will slow down.

With any reasonable value of efficiency, the cart will reach equilibrium well below wind speed.

buttershug · 05-21-2016, 03:05 PM

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Now Heinz conveniently forgets about the air's loss of energy (in the rest frame of the ground) or the ground's loss of energy (in the rest frame of the air).

He's tying himself up in knots trying to pretend the cart violates CoE, and can't even keep his own objections consistent.

And yet, you still cannot assign a value of thrust that is greater than the value of brake force without violating COE.

And yet you never back that up.

Heinz Hershold · 05-21-2016, 03:07 PM

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Now Heinz conveniently forgets about the air's loss of energy (in the rest frame of the ground) or the ground's loss of energy (in the rest frame of the air).

He's tying himself up in knots trying to pretend the cart violates CoE, and can't even keep his own objections consistent.

And yet, you still cannot assign a value of thrust that is greater than the value of brake force without violating COE.

And yet you never back that up.

And yet, the post right above yours does just that.

I suppose you either haven't read it, or don't have the brains to understand it.

semper · 05-21-2016, 03:27 PM

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Now Heinz conveniently forgets about the air's loss of energy (in the rest frame of the ground) or the ground's loss of energy (in the rest frame of the air).

He's tying himself up in knots trying to pretend the cart violates CoE, and can't even keep his own objections consistent.

And yet, you still cannot assign a value of thrust that is greater than the value of brake force without violating COE.

And yet you never back that up.

And yet, the post right above yours does just that.

I suppose you either haven't read it, or don't have the brains to understand it.

Yes Heinz, your post certainly highlights the problem. It is a terrible problem, a monumental error which you are attached to. It just won't go away, and ultimately when you realise it, your head will most likely explode. You should definitely seek expert help from as many physics and mechanics professors as you can find. Go all out, write some journal articles and send for review, do what ever you can to isolate this single item of theory.

I am sure the carteers can help by providing a multitude of similar examples. Any number of non ddwfttw case to ensure objectivity in response to the single salient item of energy and power relationship you have identified. You must do it, only you can do it Heinz. Make sure someone has a mop and bucket on standby.

Heinz Hershold · 05-21-2016, 03:34 PM

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Now Heinz conveniently forgets about the air's loss of energy (in the rest frame of the ground) or the ground's loss of energy (in the rest frame of the air).

He's tying himself up in knots trying to pretend the cart violates CoE, and can't even keep his own objections consistent.

And yet, you still cannot assign a value of thrust that is greater than the value of brake force without violating COE.

And yet you never back that up.

And yet, the post right above yours does just that.

I suppose you either haven't read it, or don't have the brains to understand it.

Yes Heinz, your post certainly highlights the problem. It is a terrible problem, a monumental error which you are attached to. It just won't go away, and ultimately when you realise it, your head will most likely explode. You should definitely seek expert help from as many physics and mechanics professors as you can find. Go all out, write some journal articles and send for review, do what ever you can to isolate this single item of theory.

I am sure the carteers can help by providing a multitude of similar examples. Any number of non ddwfttw case to ensure objectivity in response to the single salient item of energy and power relationship you have identified. You must do it, only you can do it Heinz. Make sure someone has a mop and bucket on standby.

Another typical *semper post*.

Words not connected in any way that make any sense; just keyboard diarrhea.

Maybe that's what the mop and bucket are needed for?

semper · 05-21-2016, 03:43 PM

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Now Heinz conveniently forgets about the air's loss of energy (in the rest frame of the ground) or the ground's loss of energy (in the rest frame of the air).

He's tying himself up in knots trying to pretend the cart violates CoE, and can't even keep his own objections consistent.

And yet, you still cannot assign a value of thrust that is greater than the value of brake force without violating COE.

And yet you never back that up.

And yet, the post right above yours does just that.

I suppose you either haven't read it, or don't have the brains to understand it.

Yes Heinz, your post certainly highlights the problem. It is a terrible problem, a monumental error which you are attached to. It just won't go away, and ultimately when you realise it, your head will most likely explode. You should definitely seek expert help from as many physics and mechanics professors as you can find. Go all out, write some journal articles and send for review, do what ever you can to isolate this single item of theory.

I am sure the carteers can help by providing a multitude of similar examples. Any number of non ddwfttw case to ensure objectivity in response to the single salient item of energy and power relationship you have identified. You must do it, only you can do it Heinz. Make sure someone has a mop and bucket on standby.

Another typical *semper post*.

Words not connected in any way that make any sense; just keyboard diarrhea.

Maybe that's what the mop and bucket are needed for?

Ok, I'll start. Heinz, you are flying an aeroplane North. The thrust for your configuration etc is 1000N and your true airspeed is 100m/s. Your speed over the ground is 150m/s. Calculate the power transferred to the aeroplane by the engine, after losses.

Now, you turn the aircraft around so it is heading South. Same configuration, same engine settings and airspeed, but now your ground speed is 50m/s. Calculate the power transferred to aeroplane after losses.

Heinz, please tell us the difference in power for each case. Go.

spork · 05-21-2016, 03:52 PM

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The fact that you want to dodge peer review just confirms you are a crackpot.

You know what's a really important part of the scientific process? Others replicating your results. Why do you want to dodge that part of the scientific process? It's up to others to demonstrate that the claim is right or wrong. That's you (asshole).

:

But, for how much longer do you think you can continue to dodge the HFR video?

Since I'm not going to make that video, and you're CLEARLY not going to make that video, I'm guessing forever. Is that the right answer? Forever?

MikeB · 05-21-2016, 04:14 PM

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..........

Ok, I'll start. Heinz, you are flying an aeroplane North. The thrust for your configuration etc is 1000N and your true airspeed is 100m/s. Your speed over the ground is 150m/s. Calculate the power transferred to the aeroplane by the engine, after losses.

Now, you turn the aircraft around so it is heading South. Same configuration, same engine settings and airspeed, but now your ground speed is 50m/s. Calculate the power transferred to aeroplane after losses.

Heinz, please tell us the difference in power for each case. Go.

I doubt Heinz can sort this out so I will do it. The answer in both cases is zero.

In both cases the engine inputs energy to the plane at a rate of 100,000 W. However, with the plane at constant velocity and altitude, the losses (turbulence/heat into the atmosphere) equal the input.

semper · 05-21-2016, 04:24 PM

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..........

Ok, I'll start. Heinz, you are flying an aeroplane North. The thrust for your configuration etc is 1000N and your true airspeed is 100m/s. Your speed over the ground is 150m/s. Calculate the power transferred to the aeroplane by the engine, after losses.

Now, you turn the aircraft around so it is heading South. Same configuration, same engine settings and airspeed, but now your ground speed is 50m/s. Calculate the power transferred to aeroplane after losses.

Heinz, please tell us the difference in power for each case. Go.

I doubt Heinz can sort this out so I will do it. The answer in both cases is zero.

In both cases the engine inputs energy to the plane at a rate of 100,000 W. However, with the plane at constant velocity and altitude, the losses (turbulence/heat into the atmosphere) equal the input.

Ok, fair enough. Let's now assume the drag power is not defined as a 'loss'. I should be more careful in definitions and terms.

What I want Heinz to tell us, is the difference in drag power (or thrust power if you prefer) between each case since this relates to his cart-oon.

Go Heinz.

F X · 05-21-2016, 05:36 PM

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My brother was the one that banned him.

That is awesome

F X · 05-21-2016, 05:39 PM

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Ya know, looking at humber's post history at Physicsforums has me questioning whether or not he was actually a troll.

I never thought him a troll, just delusional and unsocial. A troll would at least have some lulz now and then.

There was another poster (Spiney) who did the same thing on another forum and got banned, he was obsessed and wouldn't be rational about it.

Not Humber, but the same delusional attitude.

buttershug · 05-21-2016, 06:31 PM

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Bottom Line is:

You cannot place a value of thrust on the diagram that is greater than the braking force, without violating COE.

End of story.

But the braking force is relative to the ground, while the thrust is relative to the air, which is moving relative to the ground.

That is not true.

Both forces are relative to the cart.

The braking force acts to slow the cart, while the thrust force acts to keep the cart moving.

With 1 Watt collected by the wheels at 5 m/s, the braking force is 0.2 N

If that entire 1 Watt is available to create a thrust force on the cart, at 5 m/s, the thrust force can be no greater than 0.2 N.

Anything more than that would violate COE.

If the thrust force is 0.5 N for example, at 5 m/s that is 2.5 Watts, with only 1 Watt input. That is not possible and violates COE.

You cannot isolate the thrust force to the air, as the crackpots are doing but first consider it as acting on the cart. That way, you make no mistake about COE and you can see that ddwfttw is not possible.

A balloon in the wind goes down wind.
You keep forgetting that the wind will provide some movement for the cart and do not add that into your thinking.

Get a balloon with a string and weight dragging along the ground and it will still move down wind at a speed less than wind speed.
You keep neglecting to add this into your thinking.

MikeB · 05-21-2016, 07:32 PM

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....and you can see that ddwfttw is not possible.

Are you daft? Everyone can "see" that it is possible, as can you, as we have all seen the clear videos where the BB did not just slightly exceed windspeed, it massacred it. Richard Jenkins videoed it himself, videoed the truck-mounted anemometer showing the wind direction and videoed the BB and truck leaving the trail of dust rapidly behind. Richard stated that the wind speed at the time was about 20 mph and the BB registered 50 mph.

Some of your views would have served discussion when DDWFTTW had not yet been demonstrated. But now? You should be seeking to understand how it works.

Subduction Zone · 05-21-2016, 11:24 PM

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The fact that you want to dodge peer review just confirms you are a crackpot.

You know what's a really important part of the scientific process? Others replicating your results. Why do you want to dodge that part of the scientific process? It's up to others to demonstrate that the claim is right or wrong. That's you (asshole).

:

But, for how much longer do you think you can continue to dodge the HFR video?

Since I'm not going to make that video, and you're CLEARLY not going to make that video, I'm guessing forever. Is that the right answer? Forever?

Also an idea can become well accepted without going through peer review. Peer review as we know it did not really exist until the 20th century. There were some professional journals earlier than that, but it was not the basic "law of the land" as it is now. But if you want to know some work that never went through peer review you could look at perhaps a couple of the trouble makers that started this debate. None of Galileo's work or Newton's went through peer review. When one published he was on his own. Today at least you have people telling you when you fucked up before you make your mistakes public.

It seems that the concept of DDWFTTW is very well accepted now. All sorts of publications, and not only the ones at the crazy end of the spectrum accept it as true, NALSA, Guinness World Records, various physics groups that use it as a puzzling question. I don't know of any groups that claim it is false. Therefore it looks like, though it has not passed formal peer review public opinion is strong enough that the burden of proof is now on the deniers.

Windgrins · 05-21-2016, 11:56 PM

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Heinz,

You are in luck, no HFR video needed to understand the cart, just look at your own explanation:

http://talkrational.org/showpost.php...&postcount=129

Here's Heinz diagram of the cart and TM belt viewed from the reference frame of the ground actually using the numbers from Heinz's math:

And here is Heinz's math with the values he computed consistent with the diagram:

There are two equations that relate propeller thrust with power and velocity of the air in the stream tube:

(1). Power = Thrust ( V + dv/2 )

(2). Thrust = Area x Density ( V + dv/2 ) dv

I will first consider the case of Static Thrust, where V = 0 and use Tobemoredulls 475 mm Propeller and 1 Watt of Power.
Area is 0.1772 m^2 , density = 1.225 kg/m^3, Then:

1 Watt = T ( dv/2) and T = 0.217 dv^2/2
2/0.1085 = dv^3
dv = 2.64 m/s

Static thrust = 0.757 N

With a dv of 2.64 m/s the kinetic energy given to the air when the cart is at
Wind speed = 1/2 mv^2 where the air mass is
Area x Density x dv/2 = 0.2865 kg
KE = 0.999 Watts

You can stop right there. The cart is in still air and stationary over the ACTUAL ground just like a Cessna starting to taxi so it meets the criteria for valid "static thrust". The Net thrust is positive and numerically is 0.757 -0.2 = .557 N. And this is a perfectly valid result which violates no rules as your calculation shows. There's absolutely nothing wrong with an object having an unbalanced force on it that can do work as long as there is a source of energy (the slowing of the wind over the surface from the frame of the belt, or supplied by the belt from the actual ground frame or windframe[either since they are the same]). If I initially placed your cart on the belt with a hand holding it in place, the prop will come up to speed and the forces as shown will be produced because all the criteria (for static thrust) is met. My hand will have to supply force to resist the excess thrust and when I release the cart, the net thrust excess will cause it to accelerate. It's required by the laws of physics! This is exactly what was shown in my "merciful end video" where the restraint was the 'force bar'. An excess thrust is produced and when released, the cart accelerates:

https://www.youtube.com/watch?v=lDDaw-ve7LY

See this video below at time tic 3:10 where the behavior is exactly what you are positing--developing static thrust by being restrained, upon release, accelerating with dynamic thrust (just like a Cessna develops static thrust with the brakes held, and then starts to taxi thus transitioning to dynamic thrust):

https://www.youtube.com/watch?v=uAbc323G8CA

Mathematically Confirming the conclusion from COE that the entire 1 Watt developed at the wheels Is used to accelerate the air through the disk, and the cart gains nothing{only as long as it's restrained, once released, it starts gaining KE and angular KE in the drivetrain which reduces the amount of energy going into just accelerating the air ( actual ground frame)} (that means: creates no energy thus complying with COE) The only energy for turning the prop comes from the wheels. The only energy that the system gets comes from slowing the air over the TM surface! And what is slowing the air is the thrust from the prop.

So now, since there is net thrust on the cart (which the cart is not allowed to just ignore like Heinz attempted

), the cart will start to accelerate and as it does, since it is now moving over actual ground and not in still air, we can no longer call it "static thrust", we have to call it "dynamic thrust". Since the excess Net Thrust is quite large, the cart will start to handily accelerate. And as it does, since the prop is turning very slightly faster but the air through the prop is just slightly faster, the dynamic thrust actually increases to a higher value than the static thrust at a lower RPM so the cart continues to accelerate. Which is exactly the behavior we observe in all videos when the cart is released and the TM speed is above V_minhover--the cart accelerates with experiment consistent with the math. By the way, if one wants to compute this "dynamic thrust" for some speed that is non zero over the actual ground (red line in diagram), of course the correct values to use are the cart's airspeed (or in this case, this also happens to be the speed over actual ground--not the speed the TM belt is moving. That would be absurd).

Also, as the cart starts to accelerate, the torque turning the shaft will be split between the rotational drag of the prop which is accelerating the air over ground, increasing the KE of the cart and the angular KE of the drivetrain because it is no longer operating steady state, but accelerating. It's worth noting that if the cart was operating with a constant prop speed, the thrust would steadily decrease as the cart is moving. But since the cart is fixed geared, as it moves up the belt, the prop turns faster and is able to increase its thrust from its former value as it accelerates. This goes on until the losses (which are mostly increasing as a square of the airspeed) increase until they equal the gains from slowing the air over the belt.

If the treadmill were really really long, it would accelerate until it reaches it's limit speed where the internal losses, prop drag, and turbulence losses equal the gains and it would travel up belt at a constant velocity. (Which is exactly what the Blackbird did at 2.8X windspeed of the day).

The cart is now proven by Heinz to work as advertised and no physics laws have been violated.

No need to look for any mysterious vibrations, magic elves, pixie dust or any other magic since they would only make the car work less efficiently (or at least differently) than the theory which explains the exact behavior seen in reality (within experimental measurement error)! The carteers are all in agreement with your excellent diagram, math, and explanation here! The only way to show that this theory isn't wrong is to find a counterexample that it doesn't explain, not look for pixie dust and unicorn answers. So, for any contender, show a real world physical example under carefully control conditions that meet all the criteria and yet doesn't behave properly. Until then, thanks for all the fish!

DDWFTTW all wrapped up in a tidy package and fully explained. QED.

The End.

Bye-Bye

Every Loose end I can think of mathematically shown, diagrammed, videos supplied, documented, and cleaned up (but maybe a bit redundant for emphasis)!

Adios!

A load of SHIT!

You violated COE again, now run away again.

Nope. You need to explain exactly how instead of handwaving.

ESPECIALLY SINCE IT'S YOUR DIAGRAM AND MATH and nowhere does COE come into the derivation as stated.

We know you can't so you attempt to dismiss. Ain't flying.

PS, The whole crew is laughing at you!

Brother Daniel · 05-22-2016, 12:35 AM

:

As far as dropping a microphone is concerned, countless peer reviewed papers have been written on the force and acceleration of gravity.

Very good. So you understand that when a result follows straightforwardly from well-established theory, there's no need to have a journal paper specifically about that result.

There's no need to have a paper about Obama dropping a mic, because there's no reason to imagine that the mic would work differently from any other heavier-than-air object, and no reason to imagine that an object dropped by Obama would work differently from an object dropped by someone else. The fact that it will fall to the floor follows straightforwardly from well-established physical theory -- as anyone who has studied any physics will agree. Asking "where are the peer-reviewed papers specifically about Obama dropping a mic?" would be silly.

Similarly, there's no need to have a paper about the DDWFTTW cart, because it follows straightforwardly from well-established physical theory that the principle of the cart is perfectly sound -- as anyone who has studied physics in any depth (and has given the cart more than a couple minutes of serious thought) will agree. So asking "where are the peer-reviewed papers specifically about the DDWFTTW cart?" is silly.

:

The fact is, peer review has one specific meaning in science

Right. And the key point is that your work is checked by other scientists, chosen from among those who have expertise in the relevant domain.

There are some such people in this thread. And (as someone pointed out to me) many more such people in similar threads on other boards. Not only people with the right qualifications to act as reviewers for respected journals, but people who DO, in fact, act as reviewers for respected journals.

On message boards, people with real expertise in physics universally agree with spork -- sometimes immediately, sometimes after a bit of discussion. And it's bizarre to imagine that the very same people who agree with spork while posting on message boards would somehow take the opposite view while acting in their capacity as journal reviewers.

In short: There's nothing magical about peer-reviewed journals. It's just that your work is checked by people with the relevant expertise. But that very same sort of checking, by people with the relevant expertise, has taken place in these threads! (That, plus a lot of comedy as well.)

05-21-2016, 01:33 PM	#2652759 / #381
Brother Daniel predisposition to antagonism Kodos the Executioner Mod: HASH, Philo, Math, THC : Jun 2008 : on the shore of the North Atlantic : 15,670	Now Heinz conveniently forgets about the air's loss of energy (in the rest frame of the ground) or the ground's loss of energy (in the rest frame of the air). He's tying himself up in knots trying to pretend the cart violates CoE, and can't even keep his own objections consistent. __________________ Requiem: Everything we humans do is fully deserving of ridicule and mockery. Without a God to laugh, it falls to us enlightened fools to make up the difference.

05-21-2016, 02:53 PM	#2652793 / #385
Heinz Hershold Superior Member : Sep 2011 : 2,727	There are two equations that relate propeller thrust with power and velocity of the air in the stream tube: Power = Thrust ( V + dv/2 ) and Thrust = Area x Density ( V + dv/2 ) dv I will first consider the case of Static Thrust, where V = 0 using a prop diameter of 475 mm and 1 Watt of Power. Area is 0.1772 m^2 , density = 1.225 kg/m^3, Then: 1 Watt = T ( dv/2) and T = 0.217 dv^2/2 2/0.1085 = dv^3 dv = 2.64 m/s Static thrust = 0.757 N The static thrust of 0.757 N only exists if the cart is stationary and the thrust is only doing work on the air. No work is being done to move the propeller or the cart. Since work is being done to move the propeller on both the treadmill belt as well as the ground, the thrust is not static, but is at the dynamic level and cannot exceed 0.2 N without violating COE. Using the same equations as before, but this time V = 5 m/s: Power = Thrust ( V + dv/2 ) and Thrust = Area x Density ( V + dv/2 ) dv 1 Watt = T (5 + dv/2) and T = 0.217 (5 + dv/2) dv 2 / (10 + dv) = 1.085 dv + 0.1085 dv^2 2 = .1085 dv^3 + 2.17 dv^2 + 10.85 dv dv = 0.178 Dynamic Thrust = 0.1965 N Mathematically confirming the conclusion from COE that the Dynamic Thrust can never be greater than 0.2 N. In fact, the calculated value of 0.1965 N means the cart cannot remain at wind speed even with 100% efficiency. It will never reach wind speed, or if pushed to wind speed and released, it will slow down. With any reasonable value of efficiency, the cart will reach equilibrium well below wind speed. Attached Thumbnails __________________ RICHARD P. FEYNMAN Some remarks on science, pseudoscience, and learning how to not fool yourself. Caltech’s 1974 commencement address. If you’re doing an experiment, you should report everything that you think might make it invalid—not only what you think is right about it: other causes that could possibly explain your results. Details that could throw doubt on your interpretation must be given, if you know them. You must do the best you can—if you know anything at all wrong, or possibly wrong—to explain it.

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