Down wind faster than the wind

[humber]

George:


And yet it does it without breaking a single law of physics.

"Over unity", must not mean what you think it means.

JB

See answer to Micheal C

 

[humber]

Every book does. I already directed you to a wiki page - which you declared was all wrong. Here's a high-school physics text book: http://www.motionmountain.net/motionmountain-part1.pdf . Page 97:

Try Newton. There is also the concept of mass. Velocity is but one dimension of an object. Kinetic energy is not "relative". Unless you think that a 3kg and 6kg have 3kg relative mass. If they do, it is because they are in the same gravitational field.
Anway, none of these Galilean ideas can allow you to extract any energy form the differences in "relative frames". Theories describe the world, not make it.

 

[humber]

Standing still with respect to what???

Earlier you claimed you were an engineer. You must have studied at least a little physics at some point. Did you learn anything at all?

There. is. no. such. thing. as. absolute. velocity.


For ****'s sake, learn something.

There may be "relativity" but there is also "locality". They always forget that one.

 

[humber]

Techno, if it wasn't for the fact I majored in it, I'd question whether you were an engineer.

As it is, I simply note it's a miracle of quality control that more people don't die because of an inability to reconcile theory and fact.

FYI Sol, I've had engineers argue with me over whether a computer consuming 250W of power produces 250W of heat, and other amazingly painful things, so yes, we're entirely capable of being v. v. stupid.

Do you mean watts or watt/hours?

Whether "power" = "heat" depends upon the load. For a purely resistive load, that is correct. For a reactive load, not necessarily.
All the input energy will be converted directly to heat unless stored, or to some other form, then dissipated. Heat to mechanical motion to heat, or sound to heat. Painless, but true, as long as you know your units.

 

[humber]

Sol is right on here on two counts:

A: the car *does* self start as shown in the videos

B: Who gives a cr** if it doesn't -- that's not part of our claim.

If the silly thing *did* needed more drag to get self started it would be trivial to give it more drag -- a simple flap that sticks up and catches the tailwind and then falls backward when encountering the reverse flow accross the chassis. Get over the self starting issue already.

JB

Dubious. It is not possible to see there is loss of contact with the road. If blown hard enough, the prop is free of the ground to spin as it wishes.

You forget one thing. You are restricting you argument to one between "orthodox" and "relativistic" physics. Acceptance of the last, does not mean that it is automatically so that you have correctly implemented that hypothesis, so details are important.

 

[humber]

I don't know if this analogy will help anybody at all but consider this:
Does any aircraft "care" what the ground is doing? The only thing that matters to your aircraft is the wind that is hitting it, it doesn't matter if that means you are flying forwards, backwards, or sideways relative to the ground, it doesn't change aerodynamics.
Likewise, it makes no difference if its the air that is moving or the road that is moving in this experiment, the math is the same.

Yes, that is generally what is being discussed. The designers claim that energy cannot only be extracted from between the air and the craft, but also, that same craft can get from between the air and the ground up to and beyond windspeed. That's how the claim seems to me. Supporting calculations are not evident.

 

[humber]

At constant speed long enough for engine behavior to stabilize. Otherwise, to reproduce the conditions of acceleration on the road, the wind would have to increase to match vehicle speed as it increases, and the loading system would have to vary in the same way that the dyno drum loads do.

Assuming you have a vehicle to carry the non-driving wheels at the same exact speed and load, and excepting any difference in surface characteristics (including round drum vs flat road), yes. In both cases there are no wind effects, only a pull between the surface of the driving wheels and the restraints and/or non-driving wheels. It doesn't matter to the car which end the load is on.

Imagine pushing against the supports of a treadmill that provides a load, thus turning the belt. At constant speed, that will feel equivalent to pushing a similar load down the road at the speed of the wind. Either way you feel no wind, and a load between what you are pushing against and the surface. It doesn't matter which of those is "fixed", if the loads behave equivalently.

Thanks for the clarification. We hear a lot of what Galileo says, but can we have those that support the above idea, speak for themselves?

Can you give please give an example of two simple moving masses, where the frames idea can be used to contradict Newtonian mechanics?

 

[Michael C]

Do you consider any machine where output is faster than input to be an over-unity device?

Not faster, per se, but requires more energy than is available to get there.
More output than input.

That's not an answer to my question. Do you, in fact, consider any machine where output is faster than input to be an over-unity device?

 

[sol invictus]

Not faster, per se, but requires more energy than is available to get there.
More output than input.

humber, how much energy do you think is "available", either in the treadmill situation or outside in the wind? Why don't you estimate it and explain to us why it's just precisely enough to get the cart to wind speed and no faster? And while you're at it you might explain why sailboats and iceboats can easily sail downwind faster than the wind without being "over unity".

Try Newton. There is also the concept of mass. Velocity is but one dimension of an object. Kinetic energy is not "relative".

Yes it is - I already provided a quote for you on that, and it's blindingly obvious anyway. If you change reference frames you change velocities, and K=(1/2)mv^2. v relative to what?

Unless you think that a 3kg and 6kg have 3kg relative mass.

Gibberish. "Relative" in this context means relative to reference frame (i.e. velocity), not mass.

Anway, none of these Galilean ideas can allow you to extract any energy form the differences in "relative frames". Theories describe the world, not make it.

Good, because no one but you said anything of the sort. One can extract energy from the difference in speed between the air and the ground. One can use Galiliean relativity to prove that physics of the cart at fixed position on the treadmill are identical to the physics of the cart moving at wind speed on level ground. Those are two separate statements - if you conflate them, you get nonsense (or is it humbersense?).

There may be "relativity" but there is also "locality". They always forget that one.

Freshman texts probably don't bother to mention it (because it's obvious), but yes, that is important here as well. If the cart on the treadmill were sensitive to the treadmill's frame or the ground it's sitting on, that would indeed invalidate the comparison. Is that what you think?

 

[technoextreme]

Techno, if it wasn't for the fact I majored in it, I'd question whether you were an engineer.

As it is, I simply note it's a miracle of quality control that more people don't die because of an inability to reconcile theory and fact.

FYI Sol, I've had engineers argue with me over whether a computer consuming 250W of power produces 250W of heat, and other amazingly painful things, so yes, we're entirely capable of being v. v. stupid.

Grey I've seen you say something that would get people killed so yeah we do say stupid things.
EDIT:
After reading your statement again there is another stupid thing in that post. It's not quality control.

B: Who gives a cr** if it doesn't -- that's not part of our claim.

Well that's really dumb because you keep on comparing it to tacking. You can start from rest and then go twice as fast as the wind in a sailboat that was what I was expecting the criteria for the cart to be since you were so dead set on using that comparison.

 

[humber]

That's not an answer to my question. Do you, in fact, consider any machine where output is faster than input to be an over-unity device?

It's not a valid question Micheal C. Output? faster?

Perhaps a venturi may be what you have in mind? Then, no

 

[ThinAirDesigns]

Me regarding "self starting":

B: Who gives a cr** if it doesn't -- that's not part of our claim.

-

Well that's really dumb because you keep on comparing it to tacking.

-
First, there is more than one correct definition of "tacking", and perhaps you have settled on a different one than us. Let's get that straight. "Tacking" can be the actual *act* of executing a turn in sailing -- as in "get ready to tack". Tacking is also a generic term for sailing steady state on an angle to the wind -- as in "we are on a downwind tack". From there it can be broken down into reachs, hauls, broad, close, etc etc,

When we use the term "tacking" as in "the sails of the cart are happily tacking away as the chassis of the cart goes DDW", we mean "tacking" in the generic angled path sense. Obviously the prop blade aren't stopping and switching directions every half rotation.

In the above context, self starting is a "we dont' give a cr** aspect of this craft". If one had to give the sailboat a shove off from the dock to get it starting on it's way around the world by wind power, how many people would claim the sailboat wasn't wind powered?

Probably only you.

JB

 

[humber]

humber, how much energy do you think is "available", either in the treadmill situation or outside in the wind? Why don't you estimate it and explain to us why it's just precisely enough to get the cart to wind speed and no faster? And while you're at it you might explain why sailboats and iceboats can easily sail downwind faster than the wind without being "over unity".

Please, for the last time. These are indirect wind devices, that can do that.
This method is not available to this machine. If you claim that this cart in someway mimics this process, the please explain how it applies to a cart with a prop driving the wheels

Yes it is - I already provided a quote for you on that, and it's blindingly obvious anyway. If you change reference frames you change velocities, and K=(1/2)mv^2. v relative to what?

That is a tautology of what is already the case. If each body finds a new frame when it accelerates to a new velocity, there must be a series of "interframes". Which coalesce to become the one frame that Newton knows.
Same thing. Different bodies at different velocities within the same frame.

I asked how this makes any difference in relation to the way the world can be defined in the standard Newtonian method. How do they differently react because they are said to be in two or more frames, rather than all within that one frame. How do the laws of acceleration and energy exchange differ from Newton's explanation, and what is the quantifiable difference, should there be any?

Gibberish. "Relative" in this context means relative to reference frame (i.e. velocity), not mass.

I asked in your words please, and not for a quote from Mr Gibberish.

So all your vectors are single-dimensioned velocity vectors?

Good, because no one but you said anything of the sort. One can extract energy from the difference in speed between the air and the ground. One can use Galiliean relativity to prove that physics of the cart at fixed position on the treadmill are identical to the physics of the cart moving at wind speed on level ground. Those are two separate statements - if you conflate them, you get nonsense (or is it humbersense?).

No. You have dome exactly what I claimed above. The "object" wind has been stripped of the source that generate it, its kinetic energy, and mass to become a numerical vector to be added or subtracted at will. Adding elephants and mice.

Freshman texts probably don't bother to mention it (because it's obvious), but yes, that is important here as well. If the cart on the treadmill were sensitive to the treadmill's frame or the ground it's sitting on, that would indeed invalidate the comparison. Is that what you think?

[/QUOTE]

When somebody says "obviously" I often ask them why that is so.
See next post for cart de-construction mayhem

 

[Michael C]

It's not a valid question Micheal C. Output? faster?

It's a very simple question, and absolutely valid. There are all sorts of machine where output is faster than input. Take, for example, a basic bicycle with no gears. The back wheel turns faster than the pedals that power it. That doesn't make it over-unity.

The DWFTTW vehicle presented here is simply "gearing up" the speed of the wind relative to the ground.

 

[ThinAirDesigns]

When somebody says "obviously" I often ask them why that is so.

I will stipulate and concede this point to you humber:

When people use the term "obviously", it doesn't apply to you.

Really, you win on that one. I believe you. Nuff said. Take your trophy home and put it on the shelf next to the others.

JB

 

[humber]

It's a very simple question, and absolutely valid. There are all sorts of machine where output is faster than input. Take, for example, a basic bicycle with no gears. The back wheel turns faster than the pedals that power it. That doesn't make it over-unity.

The DWFTTW vehicle presented here is simply "gearing up" the speed of the wind relative to the ground.

Yes, but I meant which output. Velocity..torque. Just not defined is what I meant.
Gears trade off velocity for torque, but the work done is always the same.
A machine that produced more work than put into it, would be over-unity.
That gearing up is not possible, because speed will be traded for torque, so the same work will be done, but at a different prop speed.
Therefore no magical increase in velocity.

 

[humber]

The cart is a DWFTTW design. It runs with the wind, and not at an angle.
If it employs "tacking" then it must still be seen and measured as a DWFTTW?

ETA:
JB, when someone says "obviously" in this manner, it may be an agreed assumption, or someone trying to make sure that it is.
Take the tacking. I thought that this craft goes directly downwind, and you had ascribed its operation to "as if it were tacking", but still moving directly down wind?

 

[humber]

Here are some drawings of the treadmill. They are unfortunately at Rapidshare, but if anyone can suggest somewhere better, I will move them.

http://rapidshare.com/files/165327381/cart3.jpg

http://rs75.rapidshare.com/files/165328367/friction.jpg

The treadmill is so simple. It is a force balance.

1. The treadmill forces the velocity and momentum to a minima, while the wind forces these in a real cart to a maxima.

2. If realised, and idealised, this cart would not move, as any applied force would be met with an equal reaction. It would be immovable.

These problems occur, because the treadmill is part of this model.

 

[sol invictus]

Please, for the last time. These are indirect wind devices, that can do that.
This method is not available to this machine. If you claim that this cart in someway mimics this process, the please explain how it applies to a cart with a prop driving the wheels

The existence of those devices immediately falsifies your claim that this thing is "over unity". There is obviously no law of physics that prohibits a wind-powered device to travel down wind faster than the wind - because sailors do it every day.

That is a tautology of what is already the case. If each body finds a new frame when it accelerates to a new velocity, there must be a series of "interframes". Which coalesce to become the one frame that Newton knows.
Same thing. Different bodies at different velocities within the same frame.

Gibberish. Do you or do you not agree that kinetic energy depends on velocity? Do you or do you not agree that velocity depends on choice of reference frame?

I asked how this makes any difference in relation to the way the world can be defined in the standard Newtonian method. How do they differently react because they are said to be in two or more frames, rather than all within that one frame. How do the laws of acceleration and energy exchange differ from Newton's explanation, and what is the quantifiable difference, should there be any?

You're just making things up and arguing with them. The laws of physics are the same in all inertial frames - that's the whole point.

So all your vectors are single-dimensioned velocity vectors?[/B]

I have no idea what you mean by that. Please try to use standard terminology. If you're asking if the vectors relevant to the current discussion can be taken to be one-dimensional, then yes.

 

[humber]

The existence of those devices immediately falsifies your claim that this thing is "over unity". There is obviously no law of physics that prohibits a wind-powered device to travel down wind faster than the wind - because sailors do it every day.

The cart moves directly down wind, I think? Tacking devices move across the wind, forcing the craft to travel further ( that's one of a number of possibilities). The velocity can be increased, because Work=force x distance,
so there is no paradox. Direct wind faces a direct resistance to motion that presents a barrier at terminal velocity, that would require over-energy to breach.

You're just making things up and arguing with them. The laws of physics are the same in all inertial frames - that's the whole point.

I have no idea what you mean by that. Please try to use standard terminology. If you're asking if the vectors relevant to the current discussion can be taken to be one-dimensional, then yes.

So the wind, the real wind, is modeled by you in your analysis as one of those vectors? The terminology is correct. Mass is a dimension, not just a property.
If so, then the device cannot work. Newton's laws describe the conditions of failure. The question of "all the energy comes from the wind" is rebutted with "it gains energy from the earth moving beneath the wheels", or some other variant that is attributed to the air, or the cart or the ground being in different inertial frames. They are in this thread, in abundance.

If that is not the case, and it takes only the energy of the wind relative to the ground, then that is the Newtonian model, and so failure is therefore proscribed.

But it's not that simple, because a car on a dyno or belt, is said to be equivalent to the real item in wind, when it is not. A car, on a dyno or belt, that remains in position as seen by the operator standing along side, has no kinetic energy. It has no velocity.
There is not one point from which this can be achieved. If the belt is the road, it represents a moving mass. Yes, the vehicle moves away at belt speed , but its kinetic energy is not equal to that of the car, would it be going at belt speed, because for one thing, it has much less mass than the car. The idea is internally inconsistent.
Can you name one "reference frame", where you can see motion between the car and the operator standing along it? No.