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That ridiculous physics debate about that wind-powered vehicle


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Apparently a debate like this is now real life;

https://www.vice.com/en/article/pkb3pk/a-physicist-and-a-youtuber-made-a-dollar10000-bet-over-the-laws-of-physics

😂 (Link to the youtube video in the article)

Granted, the vehicle operation principle is slightly counter-intuitive, but I would not expect a physics professor to get tripped for more than 30 seconds if they really are thinking about it.

At least not to the point of starting to call in a violation of energy conservation... “Thanks to the laws of physics, I am not risking anything,” 😅

Anyway, for those who have not yet thought about this, yes it works, no it does not violate laws of physics, and there are very intuitive ways to understand that vehicle...

First of all, the energy content of the wind is not defined by its speed alone! How can there be a physics professor who believes so? A larger mass of air has got more energy content, and to move faster than the wind is nothing but a question of gearing up a leverage over the wind speed - exactly what they do by rotating a propeller by the wheels. That doesn't mean the vehicle gets more energy from the wind than is possible - it just means it leverages larger mass of air to reach higher ground speed than the wind itself.

A more intuitive version of this is to imagine an infinitely long rope, moving along its length at constant speed in a laboratory frame. Now, is it possible to build a device that is able to move along the rope faster than the rope is moving, at sustainable manner, without breaking the energy conservation law?

In a perfect vacuum, no. But if you can - for example - reach the floor of the lab, you can hold on to the rope while rotating generators against the ground, and thus create energy for crawling along the rope. The energy content of the rope is not defined by its speed alone, it also depends on its pulling force. The harder it can pull, the more energy you can generate from the ground movement. This energy can be turned into electricity and spent on electric motors, or you can simply just use some gearing to rotate a wheel against the rope (the speed being limited only by the pulling force of the rope really), and move around as you wish.

(Note that you can also discuss the same thing from the rope's inertial frame, in which case you are simply pulling energy out from the moving lab floor, much like hydropower plants pull energy from the motion of water)

Yes, in the case of the wind vehicle, the propellers are fundamentally getting their energy from the wind itself, but their motion represents a "gearing" as the propellers are rotating against the wind. There is no violation of energy conservation, because only the size of the propellers limits how much energy they can collect from the mass of air - the speed of the wind is not the limiting factor in the available energy content - the mass of the wind also contributes to the total available energy.

Questions?

Actually I have a question - where do I claim that $10000 ? 😇

-Anssi

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1 hour ago, AnssiH said:

Apparently a debate like this is now real life;

https://www.vice.com/en/article/pkb3pk/a-physicist-and-a-youtuber-made-a-dollar10000-bet-over-the-laws-of-physics

😂 (Link to the youtube video in the article)

Granted, the vehicle operation principle is slightly counter-intuitive, but I would not expect a physics professor to get tripped for more than 30 seconds if they really are thinking about it.

At least not to the point of starting to call in a violation of energy conservation... “Thanks to the laws of physics, I am not risking anything,” 😅

Anyway, for those who have not yet thought about this, yes it works, no it does not violate laws of physics, and there are very intuitive ways to understand that vehicle...

First of all, the energy content of the wind is not defined by its speed alone! How can there be a physics professor who believes so? A larger mass of air has got more energy content, and to move faster than the wind is nothing but a question of gearing up a leverage over the wind speed - exactly what they do by rotating a propeller by the wheels. That doesn't mean the vehicle gets more energy from the wind than is possible - it just means it leverages larger mass of air to reach higher ground speed than the wind itself.

A more intuitive version of this is to imagine an infinitely long rope, moving along its length at constant speed in a laboratory frame. Now, is it possible to build a device that is able to move along the rope faster than the rope is moving, at sustainable manner, without breaking the energy conservation law?

In a perfect vacuum, no. But if you can - for example - reach the floor of the lab, you can hold on to the rope while rotating generators against the ground, and thus create energy for crawling along the rope. The energy content of the rope is not defined by its speed alone, it also depends on its pulling force. The harder it can pull, the more energy you can generate from the ground movement. This energy can be turned into electricity and spent on electric motors, or you can simply just use some gearing to rotate a wheel against the rope (the speed being limited only by the pulling force of the rope really), and move around as you wish.

(Note that you can also discuss the same thing from the rope's inertial frame, in which case you are simply pulling energy out from the moving lab floor, much like hydropower plants pull energy from the motion of water)

Yes, in the case of the wind vehicle, the propellers are fundamentally getting their energy from the wind itself, but their motion represents a "gearing" as the propellers are rotating against the wind. There is no violation of energy conservation, because only the size of the propellers limits how much energy they can collect from the mass of air - the speed of the wind is not the limiting factor in the available energy content - the mass of the wind also contributes to the total available energy.

Questions?

Actually I have a question - where do I claim that $10000 ? 😇

-Anssi

You know if you think this is possible then build it, it shouldn't be too hard to build and no if it has a source of energy being in this case the wind then it is not breaking the laws of thermodynamics. The wind does have energy just like a rocket's thrust has energy(https://www.windpowerengineering.com/calculate-wind-power-output/).

main-qimg-cd7780dbd14e3005de89264595daea

So, if you had velocity of the wind of 1 m/s, The Windmill blades was 1 m^2 in size, and the density of the Air was 1 kg/m^3 then the power of that windmill would be .5 J/s, assuming 100% of the wind energy is converted into electric energy. Now the average windspeed for the entire world is 3.3081 m/s , The Average air density is 1.225 kg/m^3 and let's say that you used 1 m^2 windmill blade surface area for the car, then the power in joules per second would be 22.1738947056451125 assuming that 100% of the wind energy was converted into electric energy which is a very small amount of energy considering a gallon of gasoline contains 120 Megajoules. The low energy production from wind power is one of the reasons this isn't really feasible for a car to use.

Edited by VictorMedvil
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I'm waaaay too lazy to build this I'm afraid. I'm lucky other people already have done it already, and I have no reason to suspect trickery 😇

But yeah, we should add contributions to those calculations still, that formula is just a windmill energy capture, which is closer to how a static sail captures energy; it ignores the idea of using some of that energy as leverage by giving torque to a propeller.

The air velocity contribution is to the power of 3 (meaning small increases have large effect), and a propeller that is rotating a fast rate of knots is going to produce a strong low pressure zone in front of it, and high pressure zone behind it (it's not just pushing against the wind), making the air force contribution greater than just with a sail (the very operating principle of a propeller). In addition, some of that extra leverage contributes back to the propeller rotation speed (but obviously there are losses and there's a limit to how much you can leverage this, just like with any gearing or pulley systems).

I don't know off the top of my head how to calculate the whole system, but it involves converting linear force to propeller torque, propeller thrust calculations, and the whole feedback loop you get from it. (Hmm, actually calculating the treadmill version might not be too complicated... 🤔)

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1 hour ago, AnssiH said:

I'm waaaay too lazy to build this I'm afraid. I'm lucky other people already have done it already, and I have no reason to suspect trickery 😇

But yeah, we should add contributions to those calculations still, that formula is just a windmill energy capture, which is closer to how a static sail captures energy; it ignores the idea of using some of that energy as leverage by giving torque to a propeller.

The air velocity contribution is to the power of 3 (meaning small increases have large effect), and a propeller that is rotating a fast rate of knots is going to produce a strong low pressure zone in front of it, and high pressure zone behind it (it's not just pushing against the wind), making the air force contribution greater than just with a sail (the very operating principle of a propeller). In addition, some of that extra leverage contributes back to the propeller rotation speed (but obviously there are losses and there's a limit to how much you can leverage this, just like with any gearing or pulley systems).

I don't know off the top of my head how to calculate the whole system, but it involves converting linear force to propeller torque, propeller thrust calculations, and the whole feedback loop you get from it. (Hmm, actually calculating the treadmill version might not be too complicated... 🤔)

The energy you use to give torque to the propeller will generate less energy or equal amounts of energy to the energy used to move the propeller. No, this doesn't just generate free energy. Don't make me have to banish you to the crank motel with the other perpetual motion people. Einput - EFriction. = Eoutput

In no form is perpetual motion EVER Possible!

Anyone that says perpetual motion is possible in any way is a crank... Energy can NEVER be created or destroyed, ALL closed systems have a static amount of energy in them.

Alexander Kusenko, is obviously correct, you cannot exceed the energy from the sources of energy for a object that had no initial energy in the system. That Youtuber is wrong, In our universe that is literally impossible!

That youtuber's claims are sheer crackpottery.

Edited by VictorMedvil
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As a marine engineer with NOAA, I have heard about this years ago and, after giving it fair consideration, I came to the conclusion it is bollocks. However, there are some PhDs out there, some for it, some against it, and the Internet is cluttered with long running arguments that often get very heated and emotional.

I have not seen any mathematical approach that is convincing, although Mark Drela did write up an analysis, using some ill-defined variables, that claims to support it.

What is missing is a rock-solid demonstration that this works, which could be provided simply by releasing a neutrally buoyant balloon and watching to see if this wind mobile can pass it and stay ahead of it, or not. The fact that this simple demo has never been done is convincing evidence that this is indeed bollocks.

I am not interested in engaging in any heated arguments with the True Believers. Release the balloon and show me the video proof and spare me from all the heated arguments.

 

 

 

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20 minutes ago, OceanBreeze said:

 

As a marine engineer with NOAA, I have heard about this years ago and, after giving it fair consideration, I came to the conclusion it is bollocks. However, there are some PhDs out there, some for it, some against it, and the Internet is cluttered with long running arguments that often get very heated and emotional.

I have not seen any mathematical approach that is convincing, although Mark Drela did write up an analysis, using some ill-defined variables, that claims to support it.

What is missing is a rock-solid demonstration that this works, which could be provided simply by releasing a neutrally buoyant balloon and watching to see if this wind mobile can pass it and stay ahead of it, or not. The fact that this simple demo has never been done is convincing evidence that this is indeed bollocks.

I am not interested in engaging in any heated arguments with the True Believers. Release the balloon and show me the video proof and spare me from all the heated arguments.

 

 

 

As a Biophysicist, I entirely agree with assessment make it happen or it's bullshit, that's why I told the OP to build it and prove it. I want proof not talk, proof.

Edited by VictorMedvil
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Posted (edited)

Oh I first thought you understood how it works Victor, your answer was slightly ambiguous that way 😛

Anyway, look guys, no one is claiming perpetual motion or energy out of nothing. It is just leveraging force of wind into speed - all the energy is still coming from the air mass (it won't move without wind). What is happening is that slightly unintuitive aspect of this system is throwing people off, including Kusenko. I'm just amazed people can really with straight face start to grasp at straws so hard (I mean his arguments are pretty weak, let's face it) after this thing has been proved many times already, and especially when it's actually quite easy to understand the theory behind it if you let go of a simple "oh it just can't be faster than the wind obviously" idea (I mean sailboats do that all the time, and it can also be somewhat counter-intuitive, but also perfectly understandable).

As I explained in the OP - it's just a system that is pulling more energy than 1:1 speed from the wind by leverage. Just like an engine can turn wheels faster than the engine itself rotates. It is completely analogous to pulley, or a reverse pulley rather. A pulley is a system that converts larger distance and smaller force into smaller distance but higher force. And reverse, if you pull on the other end of the same pulley, you are converting a smaller speed into higher speed, by using more force. 

Just by complete co-incidence, Vertasium posted a follow-up just minutes ago, where they explain the same exact thing, you can see pretty ample video examples of this thing;

In fact, by a sheer co-incidence, the example given at 14 minute mark in the follow-up video is essentially what I had in mind when I was writing the OP about the rope.

image.png.77aa92e42aff0c238cc029276841f780.png

Get it? 😁

(The first video, if you have not seen it, is posted here;

If you guys still feel like this must be a crank argument, well first of all you are in good company since Bill Nye and Neil DeGrasse Dyson also seem to not get it (or they are just trolling Kusenko, I can't tell), and secondly let's discuss in more detail that rope example I presented in the OP. It's much easier to understand the idea of force-to-speed leverage with it, and then it's pretty easy to also understand how it is completely analogous to getting leverage from wind mass.

And if you still are not convinced after watching how it works from those Veritas videos (especially the follow-up which goes more into detail), I have plenty of other analogous examples in mind 😊

Cheers,

-Anssi

Edited by AnssiH
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1 hour ago, AnssiH said:

Oh I first thought you understood how it works Victor, your answer was slightly ambiguous that way 😛

Anyway, look guys, no one is claiming perpetual motion or energy out of nothing. It is just leveraging force of wind into speed - all the energy is still coming from the air mass (it won't move without wind). What is happening is that slightly unintuitive aspect of this system is throwing people off, including Kusenko. I'm just amazed people can really with straight face start to grasp at straws so hard (I mean his arguments are pretty weak, let's face it) after this thing has been proved many times already, and especially when it's actually quite easy to understand the theory behind it if you let go of a simple "oh it just can't be faster than the wind obviously" idea (I mean sailboats do that all the time, and it can also be somewhat counter-intuitive, but also perfectly understandable).

As I explained in the OP - it's just a system that is pulling more energy than 1:1 speed from the wind by leverage. Just like an engine can turn wheels faster than the engine itself rotates. It is completely analogous to pulley, or a reverse pulley rather. A pulley is a system that converts larger distance and smaller force into smaller distance but higher force. And reverse, if you pull on the other end of the same pulley, you are converting a smaller speed into higher speed, by using more force. 

Just by complete co-incidence, Vertasium posted a follow-up just minutes ago, where they explain the same exact thing, you can see pretty ample video examples of this thing;

In fact, by a sheer co-incidence, the example given at 14 minute mark in the follow-up video is essentially what I had in mind when I was writing the OP about the rope.

image.png.77aa92e42aff0c238cc029276841f780.png

Get it? 😁

(The first video, if you have not seen it, is posted here;

If you guys still feel like this must be a crank argument, well first of all you are in good company since Bill Nye and Neil DeGrasse Dyson also seem to not get it (or they are just trolling Kusenko, I can't tell), and secondly let's discuss in more detail that rope example I presented in the OP. It's much easier to understand the idea of force-to-speed leverage with it, and then it's pretty easy to also understand how it is completely analogous to getting leverage from wind mass.

And if you still are not convinced after watching how it works from those Veritas videos (especially the follow-up which goes more into detail), I have plenty of other analogous examples in mind 😊

Cheers,

-Anssi

Somehow I am sure this is some sort of misunderstanding of physics this idea of a car with more mass than the air moving faster than the wind, however I don't feel like debating it, as I said you will not create energy from nothing and the energy of the output will not exceed the energy of the input. Energy is never created or destroyed only transferred from place to place, as long as it doesn't break any of those things I am sure it works.

"The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another. This means that a system always has the same amount of energy, unless it's added from the outside."

such that the equation is as follows, (1/2)*Δt*pAir*ABlades*VWind^3 = (1/2)*MVehicle*VVehicle^2 - Efriction , which  Efriction = μMaterial Of Land*Mvehicle*gEarth*Δx

You know this stuff is really easy to calculate using Newtonian Mechanics, if it doesn't follow that equation whatever you are putting out there is wrong.

Edited by VictorMedvil
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1 hour ago, AnssiH said:

Oh I first thought you understood how it works Victor, your answer was slightly ambiguous that way 😛

Anyway, look guys, no one is claiming perpetual motion or energy out of nothing. It is just leveraging force of wind into speed - all the energy is still coming from the air mass (it won't move without wind). What is happening is that slightly unintuitive aspect of this system is throwing people off, including Kusenko. I'm just amazed people can really with straight face start to grasp at straws so hard (I mean his arguments are pretty weak, let's face it) after this thing has been proved many times already, and especially when it's actually quite easy to understand the theory behind it if you let go of a simple "oh it just can't be faster than the wind obviously" idea (I mean sailboats do that all the time, and it can also be somewhat counter-intuitive, but also perfectly understandable).

As I explained in the OP - it's just a system that is pulling more energy than 1:1 speed from the wind by leverage. Just like an engine can turn wheels faster than the engine itself rotates. It is completely analogous to pulley, or a reverse pulley rather. A pulley is a system that converts larger distance and smaller force into smaller distance but higher force. And reverse, if you pull on the other end of the same pulley, you are converting a smaller speed into higher speed, by using more force. 

Just by complete co-incidence, Vertasium posted a follow-up just minutes ago, where they explain the same exact thing, you can see pretty ample video examples of this thing;

In fact, by a sheer co-incidence, the example given at 14 minute mark in the follow-up video is essentially what I had in mind when I was writing the OP about the rope.

image.png.77aa92e42aff0c238cc029276841f780.png

Get it? 😁

(The first video, if you have not seen it, is posted here;

If you guys still feel like this must be a crank argument, well first of all you are in good company since Bill Nye and Neil DeGrasse Dyson also seem to not get it (or they are just trolling Kusenko, I can't tell), and secondly let's discuss in more detail that rope example I presented in the OP. It's much easier to understand the idea of force-to-speed leverage with it, and then it's pretty easy to also understand how it is completely analogous to getting leverage from wind mass.

And if you still are not convinced after watching how it works from those Veritas videos (especially the follow-up which goes more into detail), I have plenty of other analogous examples in mind 😊

Cheers,

-Anssi

I have no interest in “analogous examples” of leverage and gearing. First of all, you cannot leverage energy, only force. Secondly, why has the balloon test never been done? That would-be drop-dead convincing. The fact that it has never been done convinces me this is bollocks.

And, whenever anyone disagrees, even someone like Neil deGrasse Tyson, the True Believers always say that “he doesn’t get it”. That is the type of rebuttal that only a crackpot uses; anyone who disagrees just “doesn’t get it” as if there is something to get, but never explained or demonstrated in a scientifically accepted manner.

Show this thing staying ahead of a neutrally buoyant balloon and I will “get it”. Telling me it leverages the wind, without any sensible scientific explanation of how it supposedly does that, just “doesn’t get it”. Extraordinary claims require extraordinary evidence and none has ever been provided.

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Posted (edited)

Well you know,  you wished someone to build it, and someone has build it, what can I say. I agree on the sentiment though, just believing someone else is not worth much, it's much better to form an understanding of the thing yourselves. On that token, OceanBreeze I would never advice you to "get it" just by believing some demonstration; understanding is much more valuable. Let's do that instead 😇

Really your arguments that it is somehow creating energy out of nothing is merely your confusing on how it is supposed to work. Once you have figured it out, you'll be glad to notice it doesn't break any energy conservation laws - it merely converts the momentum difference between the air/ground into thrust against the air - it's really that simple. There's nothing extra-ordinary or mysterious about this, it's just counter-intuitive because you are thinking about it from an overly simplified angle - I promise you'll be kicking yourselves 😇 (and so will all the beforementioned physicists)

 

Okay, so I thought of another way to form an intuitive understanding on how that thing works, think this through carefully step by step and I'm sure you'll get it (or if not, at least identify where you think it fails).

The initial setup is this;

  • Imagine a huge and very heavy flywheel, spinning in our lab frame.
  • The flywheel is so massive, it has its own gravity (yes you know where this is going 😅)
  • We are in a good old fashioned hot-air balloon, just hovering still above the flywheel that is spinning below us.
  • The air in our lab frame is completely still.

First question; is it possible for us to collect energy from the flywheel, and use it to drive propellers, and so have means to move around the "flywheel world" freely?

Answer: Yes, we can very trivially lower a small wheel against the flywheel, and use it to drive rotors completely mechanically. We can obviously direct the propeller thrust into any direction, and thus start to accelerate to any direction we wish. Including the direction that is against the spinning direction of the flywheel (at this point we are already in fact inevitably able to "move faster than the wind" - keep reading).

So where is the energy coming from? From our perspective, it's coming from the momentum of the flywheel. How much force we are able to extract is only limited by our ability to have some "purchase" on the air - which we can improve by driving the propellers. So this propeller business yields simply leverage that allows us to extract more force from the momentum of the "flywheel" than we could with static sails.

Eventually we would have used all of the kinetic energy of the flywheel, it would grind to a halt, and our vehicle would also stop.

(Note also that if we accelerate into the same exact speed as the flywheel, the rotors would stop, and our speed would start to diminish due to air drag)

Okay, if you guys are so far with me, let's move this one step towards the actual case under discussion; instead of imagining the wheel as spinning, imagine instead that the air is orbiting the wheel at constant velocity.

Now the orbiting air represents the rest frame for our balloon - we will be moving exactly along with the "wind" if we are not getting any air thrust anywhere. Of course from our perspective the flywheel appears to be moving beneath us just like before. So again, we can lower a small wheel against the flywheel, and again we can use that rotation to drive a propeller, and use its thrust to accelerate into any direction we wish. If we simply choose to accelerate to the direction that makes the flywheel appear to be spinning faster beneath us, we will be - semantically - "moving faster than the wind" (or that is what the people living on the flywheel would say and have debates about... 😉)

Did we break energy conservation laws there? Nope. This energy is coming from is the momentum of the air, and/or from the momentum of the flywheel, depending on your frame of reference. In fact it's perhaps best to say it's coming from the momentum difference between the air and the flywheel, and from our ability to extract force (with arbitrary leverage) from that difference. Also in this case we would eventually deplete all of the momentum difference, and the whole system would grind to a halt - it's not energy out of nothing.

Likewise, if the flywheel would now also start to rotate at the same speed as the wind, that momentum difference would disappear, and your leverage would be good for nothing. Now our balloon would just grind to a halt after depleting its own momentum on air resistance. In other words, if the "wind dies out", you are no longer able to extract energy from the "ground" - it's still not free energy.

So one last step; the flywheel can obviously be thought of as "earth", and instead of a balloon and a wheel driving a propeller, we can use a land vehicle with its wheels driving a propeller. What the vehicle is doing is it is simply extracting energy from the momentum difference between air and planet earth. When that momentum difference doesn't exist (when wind is still), the vehicle will grind to a halt. When there is large enough momentum difference, the vehicle is capable of pulling energy from that difference to give itself reasonable thrust to any direction against the air momentum - including thrust towards what we land creatures call "headwind". 🙂

Let me know what part of this - if any - you find doubtful.

Cheers,

-Anssi

Edited by AnssiH
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20 hours ago, AnssiH said:

Well you know,  you wished someone to build it, and someone has build it, what can I say. I agree on the sentiment though, just believing someone else is not worth much, it's much better to form an understanding of the thing yourselves. On that token, OceanBreeze I would never advice you to "get it" just by believing some demonstration; understanding is much more valuable. Let's do that instead 😇

Really your arguments that it is somehow creating energy out of nothing is merely your confusing on how it is supposed to work. Once you have figured it out, you'll be glad to notice it doesn't break any energy conservation laws - it merely converts the momentum difference between the air/ground into thrust against the air - it's really that simple. There's nothing extra-ordinary or mysterious about this, it's just counter-intuitive because you are thinking about it from an overly simplified angle - I promise you'll be kicking yourselves 😇 (and so will all the beforementioned physicists)

 

Okay, so I thought of another way to form an intuitive understanding on how that thing works, think this through carefully step by step and I'm sure you'll get it (or if not, at least identify where you think it fails).

The initial setup is this;

  • Imagine a huge and very heavy flywheel, spinning in our lab frame.
  • The flywheel is so massive, it has its own gravity (yes you know where this is going 😅)
  • We are in a good old fashioned hot-air balloon, just hovering still above the flywheel that is spinning below us.
  • The air in our lab frame is completely still.

First question; is it possible for us to collect energy from the flywheel, and use it to drive propellers, and so have means to move around the "flywheel world" freely?

Answer: Yes, we can very trivially lower a small wheel against the flywheel, and use it to drive rotors completely mechanically. We can obviously direct the propeller thrust into any direction, and thus start to accelerate to any direction we wish. Including the direction that is against the spinning direction of the flywheel (at this point we are already in fact inevitably able to "move faster than the wind" - keep reading).

So where is the energy coming from? From our perspective, it's coming from the momentum of the flywheel. How much force we are able to extract is only limited by our ability to have some "purchase" on the air - which we can improve by driving the propellers. So this propeller business yields simply leverage that allows us to extract more force from the momentum of the "flywheel" than we could with static sails.

Eventually we would have used all of the kinetic energy of the flywheel, it would grind to a halt, and our vehicle would also stop.

(Note also that if we accelerate into the same exact speed as the flywheel, the rotors would stop, and our speed would start to diminish due to air drag)

Okay, if you guys are so far with me, let's move this one step towards the actual case under discussion; instead of imagining the wheel as spinning, imagine instead that the air is orbiting the wheel at constant velocity.

Now the orbiting air represents the rest frame for our balloon - we will be moving exactly along with the "wind" if we are not getting any air thrust anywhere. Of course from our perspective the flywheel appears to be moving beneath us just like before. So again, we can lower a small wheel against the flywheel, and again we can use that rotation to drive a propeller, and use its thrust to accelerate into any direction we wish. If we simply choose to accelerate to the direction that makes the flywheel appear to be spinning faster beneath us, we will be - semantically - "moving faster than the wind" (or that is what the people living on the flywheel would say and have debates about... 😉)

Did we break energy conservation laws there? Nope. This energy is coming from is the momentum of the air, and/or from the momentum of the flywheel, depending on your frame of reference. In fact it's perhaps best to say it's coming from the momentum difference between the air and the flywheel, and from our ability to extract force (with arbitrary leverage) from that difference. Also in this case we would eventually deplete all of the momentum difference, and the whole system would grind to a halt - it's not energy out of nothing.

Likewise, if the flywheel would now also start to rotate at the same speed as the wind, that momentum difference would disappear, and your leverage would be good for nothing. Now our balloon would just grind to a halt after depleting its own momentum on air resistance. In other words, if the "wind dies out", you are no longer able to extract energy from the "ground" - it's still not free energy.

So one last step; the flywheel can obviously be thought of as "earth", and instead of a balloon and a wheel driving a propeller, we can use a land vehicle with its wheels driving a propeller. What the vehicle is doing is it is simply extracting energy from the momentum difference between air and planet earth. When that momentum difference doesn't exist (when wind is still), the vehicle will grind to a halt. When there is large enough momentum difference, the vehicle is capable of pulling energy from that difference to give itself reasonable thrust to any direction against the air momentum - including thrust towards what we land creatures call "headwind". 🙂

Let me know what part of this - if any - you find doubtful.

Cheers,

-Anssi

You know I automatically like you because you have a cat avatar however I think this all is very unlikely to work, how about I lay some tuna on the floor instead?

Can-You-Heat-Canned-Tuna.jpg

Edited by VictorMedvil
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On 7/1/2021 at 6:38 AM, AnssiH said:

Well you know,  you wished someone to build it, and someone has build it, what can I say. I agree on the sentiment though, just believing someone else is not worth much, it's much better to form an understanding of the thing yourselves. On that token, OceanBreeze I would never advice you to "get it" just by believing some demonstration; understanding is much more valuable. Let's do that instead 😇

Really your arguments that it is somehow creating energy out of nothing is merely your confusing on how it is supposed to work. Once you have figured it out, you'll be glad to notice it doesn't break any energy conservation laws - it merely converts the momentum difference between the air/ground into thrust against the air - it's really that simple. There's nothing extra-ordinary or mysterious about this, it's just counter-intuitive because you are thinking about it from an overly simplified angle - I promise you'll be kicking yourselves 😇 (and so will all the beforementioned physicists)

 

Okay, so I thought of another way to form an intuitive understanding on how that thing works, think this through carefully step by step and I'm sure you'll get it (or if not, at least identify where you think it fails).

The initial setup is this;

  • Imagine a huge and very heavy flywheel, spinning in our lab frame.
  • The flywheel is so massive, it has its own gravity (yes you know where this is going 😅)
  • We are in a good old fashioned hot-air balloon, just hovering still above the flywheel that is spinning below us.
  • The air in our lab frame is completely still.

First question; is it possible for us to collect energy from the flywheel, and use it to drive propellers, and so have means to move around the "flywheel world" freely?

Answer: Yes, we can very trivially lower a small wheel against the flywheel, and use it to drive rotors completely mechanically. We can obviously direct the propeller thrust into any direction, and thus start to accelerate to any direction we wish. Including the direction that is against the spinning direction of the flywheel (at this point we are already in fact inevitably able to "move faster than the wind" - keep reading).

So where is the energy coming from? From our perspective, it's coming from the momentum of the flywheel. How much force we are able to extract is only limited by our ability to have some "purchase" on the air - which we can improve by driving the propellers. So this propeller business yields simply leverage that allows us to extract more force from the momentum of the "flywheel" than we could with static sails.

Eventually we would have used all of the kinetic energy of the flywheel, it would grind to a halt, and our vehicle would also stop.

(Note also that if we accelerate into the same exact speed as the flywheel, the rotors would stop, and our speed would start to diminish due to air drag)

Okay, if you guys are so far with me, let's move this one step towards the actual case under discussion; instead of imagining the wheel as spinning, imagine instead that the air is orbiting the wheel at constant velocity.

Now the orbiting air represents the rest frame for our balloon - we will be moving exactly along with the "wind" if we are not getting any air thrust anywhere. Of course from our perspective the flywheel appears to be moving beneath us just like before. So again, we can lower a small wheel against the flywheel, and again we can use that rotation to drive a propeller, and use its thrust to accelerate into any direction we wish. If we simply choose to accelerate to the direction that makes the flywheel appear to be spinning faster beneath us, we will be - semantically - "moving faster than the wind" (or that is what the people living on the flywheel would say and have debates about... 😉)

Did we break energy conservation laws there? Nope. This energy is coming from is the momentum of the air, and/or from the momentum of the flywheel, depending on your frame of reference. In fact it's perhaps best to say it's coming from the momentum difference between the air and the flywheel, and from our ability to extract force (with arbitrary leverage) from that difference. Also in this case we would eventually deplete all of the momentum difference, and the whole system would grind to a halt - it's not energy out of nothing.

Likewise, if the flywheel would now also start to rotate at the same speed as the wind, that momentum difference would disappear, and your leverage would be good for nothing. Now our balloon would just grind to a halt after depleting its own momentum on air resistance. In other words, if the "wind dies out", you are no longer able to extract energy from the "ground" - it's still not free energy.

So one last step; the flywheel can obviously be thought of as "earth", and instead of a balloon and a wheel driving a propeller, we can use a land vehicle with its wheels driving a propeller. What the vehicle is doing is it is simply extracting energy from the momentum difference between air and planet earth. When that momentum difference doesn't exist (when wind is still), the vehicle will grind to a halt. When there is large enough momentum difference, the vehicle is capable of pulling energy from that difference to give itself reasonable thrust to any direction against the air momentum - including thrust towards what we land creatures call "headwind". 🙂

Let me know what part of this - if any - you find doubtful.

Cheers,

-Anssi

That’s a nice little story you have there, but that’s all it is; a story. It certainly isn’t science; does not even qualify as a hypothesis let alone a theory. To have a hypothesis you need to put more effort into it; show some equations and numbers, in other words Do The Math. To have a theory you need to do the successful experiment that I already described with the neutrally buoyant balloon. Until then, it is a story and qualifies to be moved to Strange Claims if not Silly Claims and does not belong in Physics and Mathematics.

As I said earlier, I have neither the time nor the inclination to respond to stories but I will give you some things you might consider if you want to make your story more convincing.:

1)     If you were in a balloon travelling at the speed of the wind, and you lowered a wheel to the ground to generate some power to run your propeller, would the wheel/generator act as a brake to slow the balloon down or not? Hint: Power = Force x Velocity and F=ma.

2)     Can all of the power generated be used at the propeller to generate thrust? Hint: no power transmission system is 100% efficient and neither are propellers.

3)     With less power to drive the propeller than was generated at the wheels, can the propeller thrust ever be greater than the braking force at the wheels?

4)     Will the net force on your balloon be positive or negative? In other words, will your balloon be going faster or slower now than it was before you had this brilliant idea of lowering that wheel to the ground?

If you can answer these questions with the math, I will promote this thread to Alternative Theories. If you can show the video of this wind mobile staying ahead of a neutrally buoyant balloon, I will promote this thread to the head of Physics and Mathematics.

 

Once again, I ask you, why has this thing never been demonstrated to outrun a neutrally buoyant balloon? I’ll even supply the answer, because the jokers who have built this thing know damn well the balloon will stay well ahead of it and this is just one big bad Internet joke.

This will be my last installment to this thread for a while. As I am writing this, we are underway again, heading well out to sea from Newport, Rhode Island on a one-month science expedition to explore North Atlantic seamounts and need every bit of ship bandwidth for the telepresence experience which you can follow here, if you are interested.  

Meanwhile, have fun with your stories and analogies, you might even convince someone. But, until you can show this thing beating a neutrally buoyant balloon, there really is nothing here that is worthwhile to discuss.

 

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I like you guys too, even though I'm not too much into eating from the floor (but I do like tuna so I guess it evens things out) 😅

I didn't expect this to trip you guys up this bad, but then again the motivation for my first post that I got so surprised that physics professionals get tripped hard enough to end up agreeing to a 10k wager about this, so not sure what I expected 😅

Anyway, had you watched that last Veritasium video (titled "A Physics Prof Bet Me $10,000 I'm Wrong" ), you would have seen your arguments have been addressed there.

You would have also seen that Kusenko has already conceded the bet and he has paid Derek that 10k wager. The story doesn't say whether he finally realized how this thing works (and thus the blunder in his logic), or if he just believes overwhelming evidence and still thinks it violates energy conservation... I'd like to think it's the former 😉

Not that Kusenko's admittance of an error should persuade you to change your own minds, but maybe it will motivate you to actually take a proper look at that last video. I promise you you will be sooner or later able to find where your logic fails, and realize this whole thing is just a slightly unintuitive "gotcha" argument that makes it seem like energy conservation would obviously be broken, when in fact it is not. The fact that this thread is now in Silly Claims forum is a bit like having Monty Hall Puzzle in silly claims because someone doesn't understand the logic behind it, and also doesn't believe statistical evidence 😅

Watched it? Got it?

I'll assume you did, so just to get back to the original programming, I guess this thread turned out to become a wonderful demonstration of the difficulty of recognizing valid arguments from invalid (or "crank") ones. All the characteristics of a "crank" are present in the defense of Kusenko. The only reason you don't see it that way is because his arguments re-affirms your intuitive beliefs. That is not how scientific method works. But it is unfortunately far too often how science ends up playing out 😞 There are a lot of unfortunate examples of the sociological effects to our physical models. It's not always that trivial to recognize one's own biases.

Consider the fact that these kinds of vehicles have been built decades ago, and they work, and video evidence has existed for a long time. Here's a fairly detailed video of how to build one, and contains lots of footage of running one (it's a video about building the same treadmill vehicle that Veritas used in that follow-up video):

The reason all of this evidence gets dismissed is because of unwavering belief into one's own intuition, which makes people concoct increasingly exotic explanations to the evidence (because the evidence "just can't possibly be right"), instead of making them seriously investigate their own logic. I mean you guys have told me multiple times you are not interested of investigating my explanations too hard, and instead asking for me to build it, even though multiple people already have. The real reason you are asking for that is not that upon demonstration you would suddenly believe me, the real reason is that you don't believe I could. But whenever someone does build it, the explanation becomes something like "a gust of wind", even though the vehicle is accelerating for 30 seconds straight until it's too dangerous to go on. On the treadmill somehow suddenly reference frames are not symmetrical, or the person holding the craft is sub-consciously sucking the vehicle in with their fingers, or whatever. These are really grasping the straws, and would generally be considered crank strategies.

And yes, Neil DeGrasse Tyson and Bill Nye really did not get it. I guess they have never ran into this little brain teaser before, and it managed to trip them up. But the nice thing about science is that your title doesn't make you right - logic makes you right (as long as science is possible at all). Many people with massive credentials have made very long standing logical mistakes - physicists are only people too. I think these two gentlemen will have spent a moment to think about it, and probably understand perfectly well how this works by now.

The real reason why I was surprised about the wager was not because evidence exists - it was because I'd expect any physics professional to think about this from multiple perspective and start to see inconsistencies in their own assumptions. That was the point of my opening post - there is nothing in the laws of physics that prevents this vehicle from operating, there are only logical blunders that can trip you into thinking so.

I mean, OceanBreeze you keep asking for an experiment involving a balloon - but how do you propose that is different from the paper strips in all the videos you've seen (if you've watched the linked videos)? What's the difference? If you believe someone is fooling you with a paper strip, surely they could fool you with a balloon too, right? My point is, surely it is much better to form an understanding of the vehicle instead 🙂

Another important point is that almost all of physics is logical tautologies (if X then Y). Energy is conserved because of how we define "energy". That has got nothing to do with experiments. If we had an experiment where energy was not conserved, it would just mean we are not defining the energy content of the system consistently. Which leads me to my next important point; OceanBreeze you mentioned you are not really interested of analogies of the system, but rather the system itself. This might be a matter of preference, but at least for me a very important method of checking my logic is to try to think about it from multiple different angles - sometimes with analogies - and make sure I get consistent expectations.

For example in this case, I'd suggest people to think of this from the reference frame of the moving air. What ground-bound creatures may call "impossible faster than the wind motion", air-bound creatures just call "motion" 😄.

So from air-bound reference frame the only question is, if you use a wheel to collect energy from the moving ground, will the loss on the wheel always be at least as large as the thrust on the propeller, I.e. this question about braking force on the wheel vs thrust force on the propeller;

On 7/2/2021 at 1:11 PM, OceanBreeze said:

1)     If you were in a balloon travelling at the speed of the wind, and you lowered a wheel to the ground to generate some power to run your propeller, would the wheel/generator act as a brake to slow the balloon down or not? Hint: Power = Force x Velocity and F=ma.

The answer is no (to my bolded question)! 🙂 The energy loss would obviously be greater if we were driving the vehicle with another wheel, but the propeller represents a way to gain leverage over another medium with different momentum. Ignoring that is the gotcha!

This is what my first post is about. An intuitive way to understand it is to realize that the the propeller gives you leverage over the air. It literally is your ability to grab a better "hold" of the air. It is not free energy; if you think so you are confusing the energy content of the wind - intuitively thinking it's defined by the wind speed. But it's not, it's defined by the momentum of the air mass that the propeller is grabbing onto.

This point is explained in quite detail at around 11 minute mark in that same Veritas video I've linked to (The follow-up one). The math is also presented there, but really it's quite easy to grasp intuitively too.

The really nice thing about that video is that now this device will probably become another example in physics schoolbooks about how intuition can trip us over if we are not careful, and over time it will be a crank thing to claim that it doesn't work 🤔

On 7/2/2021 at 1:11 PM, OceanBreeze said:

As I am writing this, we are underway again, heading well out to sea from Newport, Rhode Island on a one-month science expedition to explore North Atlantic seamounts and need every bit of ship bandwidth for the telepresence experience which you can follow here, if you are interested.  

Oh thank you, I just might! 🙂

By the time you read this, hopefully all went well!

Cheers,

-Anssi

Edited by AnssiH
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Posted (edited)

For whomever it may concern, here's a pretty good video explaining how this little brain teaser actually works;

She basically goes through the same explanations I've done in this thread, but perhaps some diagrams and pretty pictures make it easier to digest.

But as said, no explanation will ever do any good for you unless you are willing to think about it. First you must get over your intuitive assumption that the vehicle is some kind of impossible closed system - because it really isn't. You have to allow yourself to think about things in order to learn anything.

I think the only reason this thing has been debatable for decades is because people who understand how it actually works are convinced enough to have never bothered to build one, and people who don't understand it do so because they never bothered to think the explanations through. The guy who build the Blackbird said that when he brought this up as a brain teaser, he expected everyone to just maybe trip over once, but then go "ah, right of course" once it's explained to them. I must say that would have been my expectation too, but it's not how we function, sadly! 😛

You know the original Monty Hall paradox managed to trip huge number of people, some with very big credentials, for a pretty long time;
 

Quote

Many readers of vos Savant's column refused to believe switching is beneficial despite her explanation. After the problem appeared in Parade, approximately 10,000 readers, including nearly 1,000 with PhDs, wrote to the magazine, most of them claiming vos Savant was wrong.[4] Even when given explanations, simulations, and formal mathematical proofs, many people still do not accept that switching is the best strategy.[5] Paul Erdős, one of the most prolific mathematicians in history, remained unconvinced until he was shown a computer simulation demonstrating vos Savant's predicted result.[6]

The full intuitive explanation is all of 1 sentence long; "2/3 boxes are empty, and either empty box choice can always be converted into a price box choice by switching after the host inserts their knowledge into the system."

I think everyone who are familiar with that paradox would agree that a 10 year old can figure it out if they are willing to think a little. So why does it require a professional mathematician to see a computer simulation before they are convinced? Because they refuse to even think about it! They completely trip over a small unintuitive aspect of the problem, and assume that everyone else is just too dumb to see that aspect, and they become completely unmotivated to think it through themselves. Instead they spend all of their energy defending the impossibility of their own misconception 🙄

-Anssi

Edited by AnssiH
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