How can an vehicle move faster than the wind that is powering it?

[ThinAirDesign]

Hm. Can't find a flaw in this argument. It does seem to eliminate all the confusing components, leaving nothing but an over-unity paradox, wherein the wheels must drive the propellor to generate more thrust than the wheels are getting from the treadmill.

Yes, it's all nice and it's all simple and it "eliminates all the confusing components" etc. Mission accomplished.

Problem is, it's just wrong as the wheels don't provide the force to turn the propellor to generate the thrust to drive the wheels.

If his argument were correct, ice-boats would not be able to achieve VMGs of over 1.0 and they do this in multiples.

JB

 

[PhysicsAddict]

He hasn't -- you're simply continue to misunderstand what he's done. I can say this with certainty as to me he's merely a phone call away.

JB

Indeed he has. Go read right here. He claims to certainly have tested it on a tensiometer.

http://www.ayrs.org/DWFTTW_from_Catalyst_N23_Jan_2006.pdf

 

[Trond]

Ok, please explain to me what part of the following I do not understand...

http://www.ayrs.org/DWFTTW_from_Catalyst_N23_Jan_2006.pdf

Line 32 and the 17 following lines, left column, starting with Fortunately...

Imho he holds the cart back and measures pull, line 40 "and tying the car to a tension gauge"

Doesn't this mean he held it back and measured tension?

 

[PhysicsAddict]

Yes, it's all nice and it's all simple and it "eliminates all the confusing components" etc. Mission accomplished.

Problem is, it's just wrong as the wheels don't provide the force to turn the propeller to generate the thrust to drive the wheels.

JB

Excellent... So let's stop right there and there on that point and work it out.

I'm saying that I am an observer in the same inertial frame as the cart on the treadmill in the hallway at the break-even point. I cannot feel any wind. Therefore the cart does not feel any wind.

So if the wheels are not powering the propeller and there is no wind that is powering the propeller then please explain what is it at this point that spins the propeller.

We do agree that the propeller is spinning correct? And that something does indeed have to power it correct? Please explain what that force is that is powering the propeller.

 

[Trond]

I'm too slow

And welcome aboard...finally someone that seems to be thinking in the same box as I do

 

[ThinAirDesign]

Indeed he has. Go read right here. He claims to certainly have tested it on a tensiometer.

http://www.ayrs.org/DWFTTW_from_Catalyst_N23_Jan_2006.pdf

Indeed he has not. You're confusing the argument between Trond and I.

Trond says the tensiometer test is done with "no wind" (that's his quote). This is simply not true.

The test was done on a treadmill and as any PhysicsAddict will know, there is the *same, exact* wind available to this device on a treadmill moving 10mph in a room as there is in a 10mph wind out on the street.

ALL of Jack's tests and video have been performed WITH WIND.

JB

 

[ThinAirDesign]

I'm too slow

And welcome aboard...finally someone that seems to be thinking in the same box as I do

LOL Trond -- it's a bit speedy back and forth, that's for sure. :-)

JB

 

[Trond]

Uh, the report says "in still air" did he misunderstand?

 

[Trond]

LOL Trond -- it's a bit speedy back and forth, that's for sure. :-)

Sure is

 

[PhysicsAddict]

Indeed he has not. You're confusing the argument between Trond and I.

Trond says the tensiometer test is done with "no wind" (that's his quote). This is simply not true.

The test was done on a treadmill and as any PhysicsAddict will know, there is the *same, exact* wind available to this device on a treadmill moving 10mph in a room as there is in a 10mph wind out on the street.

ALL of Jack's tests and video have been performed WITH WIND.

JB

Ok, call me dumb but directly from the link I posted:

For those who missed that July issue, No. 21, a vehicle on a treadmill in still air, with the wheels going eight miles per hour is the same as a vehicle going eight miles per hour down wind, in an eight mph following wind. If a car moves forward on a treadmill with no assistance, it is going faster than the wind

After leveling the track, putting a backstop on to get the car up to speed, and tying the car to a tension gauge, we started the treadmill and increased the speed in one mile per hour increments. ...

That really looks like a treadmill test with a tensiometer with no wind.

 

[Trond]

Sure does to me 2

 

[ThinAirDesign]

That really looks like a treadmill test with a tensiometer with no wind.

Are you really trying to tell me that you have the handle "PhysicsAddict" and don't understand simple physics frames of reference? -- I mean, no offense if you don't ... we all have to learn sometime, but this is very basic stuff and I assume a physics addict would have covered this a long time ago.

Wind is relative as is all motion.

To a treadmill moving 10mph in a room -- there is 10mph of wind. If I put you in a large enough room on a large enough treadmill would simply could not tell which was moving -- the room or the air. In fact, it matters not which -- all tests return the same results.

10mph wind in the street -- 10mph treadmill in the bedroom. Same exact "wind".

With the treadmill test, if you want the "wind" to stop -- you must turn off the treadmill.

JB

 

[PhysicsAddict]

Are you really trying to tell me that you have the handle "PhysicsAddict" and don't understand simple physics frames of reference? -- I mean, no offense if you don't ...
JB

So now I take it that we are arguing that Jack Goodman's definition of "still air" means that he actually had a room with 10mph air blowing across his treadmill.

Is this what you are now claiming? Please explain. If I am standing stationary next to the treadmill and the cart is on the treadmill at the break even point stationary with refrence to me) and I do not feel any wind since we are in "still air" please explain how the cart which is in the exact same of inertial reference as me (the observer) experiences a 10 mph wind.

To further calrify the question:

If I run on the treadmill which is set to 10mph and I am in a room with still air do you think I feel a 10mph breeze on my face?

 

[rcgldr]

red x

It's a .gif image.

It's working now, as stated, it takes a while before an attached image is approved, so I normally post a link as well when I do attachments.

fan blowing on sail

This is the same principle as a thrust reverser on a jet engine.

Not quite, the jet engine uses a compressor and heat to create a huge pressure jump. You'd need a strong power source and a prop with a pressure jump to higher than ambient to pull this off. A high efficiency prop wouldn't work, because the pressure jump occurs below ambient, and air is decelerating once it passes through the prop disk.

If it can go downwind faster than the wind, then it can sail when there is no wind.

The device is relying on the difference between wind speed and ground speed as a source of power, which is independent of the device speed. In the case of the treadmill, the treadmill is moving backwards while the air is still. In the case of the outdoor run, there's a tail wind and the ground isn't moving.

Although wind versus ground speed is independent of device speed, which allows for the concept of apparent wind to work, there is a limit to downwind speed (Vmg = Velocity made good). The sail has to divert the apparent wind so that it generates a force in the true direction of travel of the device.

For Vmg/Vt to be greater than 1, it would seem that this same diversion of apparent wind has to include an upwind component > (Vmg - Vt), otherwise there would be a net drag in the direction of the wind. I haven't seen this aspect of the issue explained.

Assuming the formula stated for a device with a Beta of 14 degrees, I made a graph of Vmg/Vt versus heading offset from true down wind. It peaks at about 2.56 at 38 degrees.

http://jeffareid.net/misc/dwvhdg.gif

Getting back to the original post, the issue is propeller efficiency, and the ability for the propeller situation to turn into a situation similar to the apparent wind situation of a ice or land sail boat. Even with no drag, there's an induced efficiency factor that limits the efficiency of propellers (I think this is related to the fact that a propeller operates in it's own induced wash). Propellers can have overall efficiency factors greater than 90%. I'm not sure what is required for the device shown.

 

[nixy2]

OK...Question 1.

Trolley with prop at zero degrees. (could even be just a rotating disc) Assuming no mechanical drag. What might be the highest speed the trolley could achieve?

and are the wheels producing thrust or drag at this condition?

 

[Trond]

Not quite, the jet engine uses a compressor and heat to create a huge pressure jump. You'd need a strong power source and a prop with a pressure jump to higher than ambient to pull this off. A high efficiency prop wouldn't work, because the pressure jump occurs below ambient, and air is decelerating once it passes through the prop disk.

Doesn't a thrust reverser just divert the airflow?

Just like on a water jet?

 

[rcgldr]

... cart is on the treadmill ... explain how the cart ... experiences a 10 mph wind.

It doesn't, it experiences 0 wind speed and -10mph speed at the wheels.

If I run on the treadmill which is set to 10mph and I am in a room with still air do you think I feel a 10mph breeze on my face?

If you stand on the treadmill while it's moving at -10mph you will experience the equivalent of a +10 mph tail wind.

fan on a sail similar to jet engine reverse thrust

Not quite, the jet engine uses a compressor and heat to create a huge pressure jump. You'd need a strong power source and a prop with a pressure jump to higher than ambient to pull this off. A high efficiency prop wouldn't work, because the pressure jump occurs below ambient, and air is decelerating once it passes through the prop disk.

Doesn't a thrust reverser just divert the airflow?

Yes, but note that the engine is also sucking in air. The intake accelerates the air backwards, the diverted nozzles accelerate the air forwards, with the result of opposing forces. There has to be an increase in kinetic energy of the air being accelerated forwards by the diverters before there's a net braking effect. In the case of a jet engine, there's a huge pressure jump well above ambient because of combustion. Note that a propeller operates in it's induced wash, the pressure of the air just before it crosses the prop disk is below ambient. If the pressure jump doesn't cause the pressure to exceed ambient, then the air starts deceleration once it's past the aft side of the propeller disk, reducing it's kinetic energy over time and distance, and in this case, the diverters would just reduce thrust, not reverse it.

 

[nixy2]

OK...Question 1.

Trolley with prop at zero degrees. (could even be just a rotating disc) Assuming no mechanical drag. What might be the highest speed the trolley could achieve?

and are the wheels producing thrust or drag at this condition?

Oh alright, I'll answer it myself.

In a 10 kt wind I'd suggest the highest speed of the trolley to be say 10kt... but no higher...and at this condition the wheels are producing neither drag nor thrust?

and as a matter of interest if I were sitting on this trolley, would I feel any wind at all?

 

[Trond]

If you stand on the treadmill while it's moving at -10mph you will experience the equivalent of a +10 mph tail wind.

I've done my share of running on a treadmill, but I've never seen one that moves so that I've experienced any tailwind and I have had the belt going at more than 10 mph

 

[PhysicsAddict]

It doesn't it experiences 0 wind speed and -10mph speed at the wheels.

If you stand on the treadmill while it's moving at -10mph you will experience the equivalent of a +10 mph tail wind.

Yes and yes. But we are not standing still on the treadmill. We are running at 10mph. Just like the cart.

So, if it experiences 0 wind speed and 10mph belt speed then what is it that is powering the propeller. Since ThinAirDesigns hasn't answered, I pose the question to you Jeff.

 

[rcgldr]

So, if it experiences 0 wind speed and 10mph belt speed then what is it that is powering the propeller. Since ThinAirDesigns hasn't answered, I pose the question to you Jeff.

Great, and I'm still not convinced it works yet. Start with a simpler case, a very long treadmill, and the device has drag inducing device, say a parachute or a solid disk. The air applies a forwards force to the device, while the treadmill applies a backwards force to the device. In this case the wheels could be connnected to a generator which would create power. The point here is that if the cart is moving slower than the belt speed due to aerodynamic forces, then power from the wheels can be harnessed.

The next leap of faith is if the wheels power a propeller, can the propellor operate in an "apparent wind" situation that allows the propellor generate thrust at speed faster than the treadmill speed? Note that the source of power is the difference between wind and treadmill speed, independent of the device speed. Assuming the ice and land boaters aren't all involved in a hoax, apparently those devices can travel downwind faster than the wind speed, as long as they have sufficient cross wind speed.

Again, my issue is that the propeller is operating in it's own induced wash, which limits it's efficiency, so I don't know if the efficiency issue is enough to keep it from working.

 

[PhysicsAddict]

The air applies a forwards force to the device

Jeff,

This could only be true if the device is moving. Think of it like this: When you are running on the treadmill at 10mph in a room with still air does the air pressure on your back assist you IN ANY WAY at maintaining your forward speed? Before you answer, remember that the air pressure on your front side is exactly the same.

If you use a generator and a motor and a drogue chute you are only obfuscating the model. Simply go back to the original model I stated. Can you continuously absorb 10N of force from the belt and use it to continuously produce 10N of thrust in order to stay stationary on the belt?

Even though I have thought about it, I haven't even addressed the issued of it churning through it's own ring vortex yet. I think that only puts more nails in it.

Edit:

Keep in mind that I do not believe that the entire land sailing community is in on some sort of hoax. If it is indeed possible that iceboats can develop a downwind VMG greater than wind speed then I believe that we are all missing something as we collapse the model down to a cart on a treadmill.

I just need simple answers to simple questions like the ones I have asked in order to find the kink.

 

[ThinAirDesign]

Sorry guys. I didn't drop out of the exchange ... had to do some real work.

I'm enjoying the tone of the discussion and will return.

JB

 

[spork]

Since you now understand these two simple ideas, you can now conclude that the video can only be either:

A. A hoax.
B. Some other "artifact" captured on film.

Well, since you've be able to prove this impossible with absolute simplicity and certainty, you should let me hook you up with this $100K bet. How would you like some free money?

 

[Trond]

Can you continuously absorb 10N of force from the belt and use it to continuously produce 10N of thrust in order to stay stationary on the belt?

No, not if you count in friction and apply those 10N on something also rolling on the belt.
However if you apply those 10N on something that is standing still (the air) then that is a completely different matter.

Spork actually gave a good example with a yoyo. Put it on the table with the cord coming out under it. Make sure the yoyo has a few turns of the cord at least. Pull slowly so it doesn't slip and watch the yoyo roll up the cord faster than you move the cord. The force you put on the yoyo's center by pulling the cord is transferred to the table and the yoyo moves faster than your pull.

 

[spork]

Not quite, the jet engine uses a compressor and heat to create a huge pressure jump. You'd need a strong power source and a prop with a pressure jump to higher than ambient to pull this off. A high efficiency prop wouldn't work, because the pressure jump occurs below ambient, and air is decelerating once it passes through the prop disk.

I'll locate the video link. A buddy did just this by sticking a small electric fan on a little cart. It certainly wasn't very efficient, but it worked.

Great, and I'm still not convinced it works yet.

Fair enough (although I assure you that it does). Are you convinced that an ice-boat can tack downwind such that its downwind velocity component is greater than the wind speed?

 

[Trond]

Is the bet really your only agenda Spork since you keep on asking about it or is it pondering about a problem which seem to drive the rest...I'm beginning to agree with the guy that mentioned nigerian scam on RR...it's boring.

 

[ThinAirDesign]

Back for a moment:

A serious question for PhysicsAddict and Trond. I need to know your stance before I can respond.

Are one or both of you stating that the cart will respond/behave differently on the street with a 10mph wind as compared to in the basement on a treadmill set to 10mph?

It appears that you feel it will act differently in the two environments.

JB

 

[ThinAirDesign]

Is the bet really your only agenda Spork since you keep on asking about it or is it pondering about a problem which seem to drive the rest...I'm beginning to agree with the guy that mentioned nigerian scam on RR...it's boring.

I think you will find that "the bet" is only on Spork's agenda when someone is only interested in stating with absolute certainty "it's a physics impossibility".

If the bet was Sporks only agenda, he wouldn't be interested in explaining how it works to people who hold at least a sliver of open mind that it might work.

After all, if they're not interested in an exchange -- only "it's violates the laws of physics", where else is there to go? It they're soooo right, it's easy money.

JB

 

[spork]

Is the bet really your only agenda Spork since you keep on asking about it or is it pondering about a problem which seem to drive the rest...I'm beginning to agree with the guy that mentioned nigerian scam on RR...it's boring.

The bet is for people that are positive this is impossible - people like you.

For those that want to discuss it, I think you can see I'll go to any length to describe how it works, provide analysis, give examples, etc.

What's boring is hearing from people who seem just as certain as I am until they're invited to put their money where their confidence is.

 

[nixy2]

I'll locate the video link. Are you convinced that an ice-boat can tack downwind such that its downwind velocity component is greater than the wind speed?

FWIW, Your vector diagram has convinced me you are right (I think). But also the vector diagram would also show an ice-boat can not go DDWFTTW, whereas the 'wind trolley' can?
With emphasis on the D

 

[rcgldr]

The air applies a forwards force to the device, while the treadmill applies a backwards force to the device.

This could only be true if the device is moving.

I was assuming the cart was moving in that example. Assume a long treadmill and nothing but air resisting the carts movement. The treadmill moves the cart backwards, and the air resists this movement with a forwards force. Assuming there is drag on the wheels, the treadmill exerts a backwards force onto the cart.

When you are running on the treadmill at 10mph in a room with still air does the air pressure on your back ...

The surrounding air isn't moving, only the air affected by the propeller.

Can you continuously absorb 10N of force from the belt and use it to continuously produce 10N of thrust in order to stay stationary on the belt?

Newtons' 3rd law at work here. The forces are always equal and opposite if the cart is not accelerating. The issue here is at what cart speed will the forces be equal? Can the forces be equal if the cart is moving forwards?

Back to the OP

How can an vehicle move faster than the wind that is powering it?

Because the source of power isn't the wind but the difference between wind speed and ground speed, which is independent of vehicle speed. The question is can the cart utiize this source of power while moving faster than the apparent wind on the cart, because the propeller blades experience a different apparent wind?

 

[ThinAirDesign]

If I run on the treadmill which is set to 10mph and I am in a room with still air do you think I feel a 10mph breeze on my face?

No.

The situation that you describe above is exactly the same as being on the street and running 10mph with a 10mph tailwind.

We really do need to get past this frame of reference issue before we move on -- it may well be a simple misunderstanding between us (and that may well be my fault).

This all started when Trond used the term "no wind" when discussing the cart on the treadmill. I'm just trying to make sure we are all using the term "no wind" the same. There's 'wind or not' relative to the chassis, 'wind or not' relative to the sails, 'wind or not' relative to the ground, 'wind or not' relative to the treadmill surface, and now there's 'wind or not' relative to my face. If when we say "no wind" and we don't establish *relative to what*, we can't have much of a productive conversation.

I don't mean to be difficult, but there can only be "simple answers" if all the small definitions are worked out.

JB

 

[PhysicsAddict]

Are one or both of you stating that the cart will respond/behave differently on the street with a 10mph wind as compared to in the basement on a treadmill set to 10mph?

It appears that you feel it will act differently in the two environments.

JB

And my answer is that I don't know for sure. Here is where I'm at:

1. The iceboaters of the planet certainly claim that a VMG downwind is a piece of cake. There's lots of them and only one of me so I'm inclined to follow along.
2. It would seem that you could take all the principles of the iceboats and squeeze them into a cart with rotating sails and the kinematic constraints of wheels to build a cart that will go DDWFTTW.
3. Jack Goodman claims to have built such a cart and posted the Youtube video which gets me excited but is hard to accept for documented evidence as "proof possible" since what we could be witnessing are artifacts of the experiment and like all good experiments really needs independent confirmation.
4. When I try to reduce it all down into an environment that would reduce the possibility of any such artifacts and would be much easier to test, control and document (the cart on a treadmill), I run into the issues I stated on my first post.

It is certainly a quandary.

After all, if they're not interested in an exchange -- only "it's violates the laws of physics", where else is there to go? It they're soooo right, it's easy money.
JB

You and I were having a nice exchange, Jeff and I were having a nice exchange. Nevertheless here we are with the betting.

I really only asked simple questions and expected only simple answers but the only one who would do so is you and Jeff.

Newtons' 3rd law at work here. The forces are always equal and opposite if the cart is not accelerating. The issue here is at what cart speed will the forces be equal? Can the forces be equal if the cart is moving forwards?

Hey! Just run the speed up on the treadmill until it appears to break even and there you have it. If you can get to that point I believe you can "go all the way".

What's boring is hearing from people who seem just as certain as I am until they're invited to put their money where their confidence is.

Why? How confident someone is on his/her position is irrelevant to this entire discussion. I know someone who was confident enough that the Patriots would win the Super Bowl that they dropped 25 large on it. It goes to show that how much money someone is willing to put on something has nothing to do with how correct they are. If you find it boring you should move along and we will continue to discuss it here.

This is a nice board and it appears to have lots of really bright contributors so I thought it would be nice to jump in the exchange here. I'm new here and only feel like I'm a guest so I am not going to hang around here while it turns into a slagging match.

Here is one thing I will leave you with:
I have now gone full circle on this. I originally argued that it was a "no-way no-how" thing. Then as it turned out to be possible with land yachts and iceboaters I could only believe that it's certainly possible to collapse it down to a cart heading directly downwind. When I saw Jack Goodman's video I thought "holy cow I got to build me one of those!" Then as I pondered the treadmill dilemma I started scratching my head again. But I didn't let it slow me down.

So here's mine:
http://s167.photobucket.com/albums/u123/DarwinAward/

I wish I had more but that was a hard drive crash ago. I built and rebuilt that cart 3 times after those pictures and video. Not shown in the photos or video is that in it's final form I could regear it at in only minutes. With the 4 sets of gears and 4 sets of wheels I had I could set it a full 300% above the cart pitch ratio that Mr. Goodman specified as well as 300% below. I had 5 different sets of blades including one homemade set laminated together using fanned out balsa that looked as close to Jack's as I could get. My cart had one other really nice attribute - I had variable pitch that I could adjust in real time. It was a blast to build and a blast to tinker on with one exception: it would never make forward progress on the treadmill.

But here is the thing that really bugs me: Jack Goodman built a cart and put it on a treadmill and he could run the treadmill from 0mph to 4mph where the cart would get lighter and lighter on the scale until it was "break-even" at 4mph. He could then increase the treadmill speed and it would increase the pull on his tensiometer as it would try to make forward progress on the treadmill.

I however, built my device and tested it using every combination of gearing, wheels, blades and pitch settings and in EVERY case my cart would only exhibit more force on the scale as the speed of the treadmill was increased. There was no combination of any of the variables that showed any promise of getting lighter on the scale as the treadmill speed was increased. Not only did I fail, I wasn't even in the ballpark.

The beauty of it all is that this only proves that I don't know how to build a cart that will make forward progress on the treadmill. I'll be the first to admit it. Whether it means that it is impossible to do or that I just suck at it I don't know. That is what is so cool about the whole deal - you can never disprove it but it may be possible to prove it can be done.

So here's my challenge to you, especially you "YaySayers": Get to it. What the hades is everyone waiting on? It didn't take me 4 hours to get it built the first time around and maybe $50 worth of old RC Helicopter parts. Go build one and put it on on a treadmill and give us some videos. I will certainly want to get with you afterwards and make mine work (no kidding, no sarchasim). Even if you are a "NaySayer" you will have a blast I promise. Just do it. Let me put it to you this way: I'd bet that there 100 folks on here and on 20 other forums on both sides of the argument that have spent 100 hours typing about it and STILL haven't run out to the shed and start wrenching about it! Go figure. Blows my mind.


Good luck and I will check back from time to time to see if anyone has gotten off of their lazy butts and posted up some videos!

 

[ThinAirDesign]

Hey PhysicsAddict, if you don't mind, I'd like to take you back to an earlier post of yours (quoted in full at the end of this post). I'm also going to reference a portion of an earlier post of mine.

The above is no different than taking two ice-boats on mirror zig-zag downwind tacks and placing a sliding beam between them -- give me two seats and a windsock right in the middle of the beam between the boats. You and I sit in those seats and watch the windsock. Yep, sure enough ... at the moment we reach the real wind speed, the sock hangs limp. Do the twin ice-boats that we are riding on care? ... of course not -- they are zigging and zagging and see plenty of wind as they accelerate us both to a VMG of greater that 1.0 and the sock turns into our face.

1: It's been established earlier in this thread via links to the NALSA website and forums that ice-boats and land yachts can and do regularly achieve VMGs far greater than 1.0. (if you don't agree, speak up now 'cause we need to backtrack and you might want to argue with them about it.)

2: Given "1", I would ask you to place the above twin ice-boats on your below treadmill (humor me please ... ok?). Remember, in the above scenario, you and I are sitting side by side between the boats(facing forward or downwind), riding an equally telescoping beam stretching from boat to boat, and we have a wind sock attached to our seat beam that is staring us in the face (in other words, it's operating in *our* frame of reference). We are in fact the *drivers* of this twin ice boat and our drivers seats are located in the exact dimensional, mechanical and CG center of this ship. We also happen to travel *directly* downwind.

In your below scenario, perform the exact same thought experiment with the twins as you do with the cart -- that is you and I take the twins up to the speed that the sock between us is hanging limp.

Now, apply all the same logic to the twins at this moment that you did to the cart (especially the part below that I bolded).

Of course, given "1", we both know that the twins will power right past this "zero" point and fill the windsock with what appears to us to be a headwind.

So now the question ... Are you and I, zipping across the ice with an apparent headwind (while actually having a ground referenced tailwind) a

A. A hoax?
B. Some other "artifact" captured on film?

Thanks in advance for your answer

JB

In order to understand this you need not understand sailing, relative wind, apparent wind or ANYTHING other than Newtons 1st law.

To get your head around this, imagine the cart facing west sitting on a long treadmill in a long windless hallway. Start the treadmill which runs towards the east and slowly increase the treadmill speed until the cart is at the perfect “break even” point. In other words, to an observer standing still in the hallway, the cart appears to also be standing perfectly still even though it is on the treadmill with its wheels spinning and propeller turning. This is the point where the cart goes EXACTLY as fast as the wind downwind. We don’t need it to go faster than the wind downwind yet. Right here at the break even point is the best place to get your head around it.

Now you don't need to understand anything more that two simple ideas:

1. You must understand Newton’s 1st law of motion - specifically pertaining to balanced and unbalanced forces. In order for the cart to appear to stand perfectly still on the treadmill, the forces pushing on the cart from the east must equal the forces pushing on the cart from the west.

In other words, let’s say that the treadmill is expending 10 Newtons of energy driving the cart east. Since the forces are balanced, the propeller on the cart must be expending 10 Newtons of energy driving the cart west in order to hold it stationary. Since the cart is not experiencing ANY wind pushing it at this point, all its energy driving it west must come from thrust generated by the propeller.

2. You must understand that mankind has yet to invent a machine simple or complex that outputs 100% of the energy it consumes. A propeller is at best 85% efficient. Add in the other components of friction and well it all goes downhill from there. In other words it would be impossible for the cart even get to this break even point. It will never generate thrust equal to the energy it consumes. Now to go even faster than the wind it will have to generate thrust IN EXCESS of the energy it consumes which of course is never going to happen.

Since you now understand these two simple ideas, you can now conclude that the video can only be either:

A. A hoax.
B. Some other "artifact" captured on film.

So here it is reduced to it's minimum components. Nothing to obfuscate here. Very simple.

If you contend that it is possible then all you need to answer is this simple non-obfuscated problem:

Let's suppose that the treadmill imparts a continuous 10 Newtons of force where the treadmill belt strikes the wheels. Please lay out the equations for me assuming your propeller is 90% efficient (that would be an awesome propeller BTW) and there is no friction in the inner gearing of the device. Show me where the device is able to generate continuous thrust in excess of 10 Newtons in order to break even and stand still.

It's a simple equation I assure you. If you need the equation I can point you toward it.

So if you would please lay it out for us where 10N into the propeller results in >= 10N of thrust out.