Risking My Life To Settle A Physics Debate

Everyone will say this craft breaks the laws of physics. This video is sponsored by Kiwico, For 50% off your first month of any subscription crate from KiwiCo (available in 40 countries!) head to www.kiwico.com/Veritasium50

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A HUGE thanks to Rick and Neil for letting me drive Blackbird. Check out Rick's CNglobal Channel for more in depth videos and explanations on going faster than the wind downwind -- ve42.co/Rick

Gene Nagata made the shoot possible. If you’re a video nerd like me, check out his channel, Potato Jet: cnglobal.infof... .

Xyla Foxlin for made the model cart used in this video. Xyla builds amazing things like rockets and canoes, check it out! cnglobal.info

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References
Jack Goodman's CNglobal video -- ve42.co/Goodman
Rick's treadmill footage -- ve42.co/Treadmill
Rick's multiple explanations of how Blackbird works -- ve42.co/DDWFTTW
Forum discussions -- ve42.co/forum Blog -- ve42.co/blog1 and retraction ve42.co/BlogRetraction

Gaunaa, M., Øye, S., \u0026 Mikkelsen, R. F. (2009). Theory and design of flow driven vehicles using rotors for energy conversion. In EWEC 2009 Proceedings online EWEC

Md. Sadak Ali Khan, Syed Ali Sufiyan, Jibu Thomas George, Md. Nizamuddin Ahmed. Analysis of Down-Wind Propeller Vehicle. International Journal of Scientific and Research Publications, 3, 4. (April 2013) ISSN 2250-3153. (www.ijsrp.org)

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Special thanks to Patreon supporters: Bill Linder, Paul Peijzel, Crated Comments, Anna, Mac Malkawi, Michael Schneider, Oleksii Leonov, Jim Osmun, Tyson McDowell, Ludovic Robillard, Jim buckmaster, fanime96, Juan Benet, Ruslan Khroma, Robert Blum, Richard Sundvall, Lee Redden, Vincent, Marinus Kuivenhoven, Alfred Wallace, Arjun Chakroborty, Joar Wandborg, Clayton Greenwell, Pindex, Michael Krugman, Cy 'kkm' K'Nelson, Sam Lutfi, Ron Neal

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Thanks to James Lincoln for building the initial prototypes for a model blackbird.

Written by Derek Muller, James Lincoln, and Petr Lebedev
Animation by Mike Radjabov and Iván Tello
Filmed by Gene Nagata, Derek Muller, Trenton Oliver, AJ Fillo and Emily Zhang
Edited by Trenton Oliver
Music from Epidemic Sound epidemicsound.com
Additional video supplied by Getty Images
Produced by AJ Fillo

评论 

  1. Veritasium

    Veritasium

    个月 前

    If you want more detail on the explanation here it is: 1. The car is powered only by the wind. There is no motor or batteries of any kind. 2. The propeller does NOT spin like a windmill. The wind does NOT push it and make it turn. 3. Instead the wheels are geared to the propeller to turn it the opposite way, like a fan, so it pushes air backwards. 4. To start the vehicle the wind simply pushes on the whole vehicle (like a block of styrofoam) and gets it moving. 5. The wheels are turning so they turn the propeller in the opposite direction to how the wind is pushing it. 6. The prop is pushing air back so air pushes the prop forwards, accelerating the car. 7. Once you get up to wind speed there is no apparent wind on the vehicle. If the prop were spun like a windmill this would mean no more thrust. But, since the prop is operating like a fan, it still accelerates air backwards, generating thrust. 8. You can go faster than wind speed continuously because even when going faster than the wind, the prop can still accelerate air backwards (in the car's frame of reference) generating thrust. In a stationary frame of reference you would see that the wind behind the propellor is slower than the surrounding air. So it's clear that the energy is coming from the wind. FAQ: If power is coming from the wheels to turn the prop, why doesn't that slow down the wheels more than it gets the prop to push back? A: Because the wheels are moving over the ground much faster than the prop is moving through the air (because there's a tailwind). Example: Let's say the car is going 12m/s in a 10m/s tailwind, so faster than the wind (note the prop will be moving through an apparent headwind of 2m/s). Power = Force x Velocity Let's say the chain applies a drag force of 100N on the wheels to drive the prop. This means we're taking power from the wheels = FxV = 100N x 12m/s = 1200W If we apply this power to the fan, it can create a force of F = P/V = 1200W / 2m/s = 600N Admittedly I've assumed no losses, but even if we waste half the power, we'd still get 300N of thrust which is more than the 100N of drag the prop adds to the wheels. The key is that we're harvesting power at higher speed, lower force, and deploying it at lower speed, higher force (which is only possible because we have a tailwind - in still air this wouldn't work because the relative velocity of the wheels over the ground would be exactly the same as the relative velocity of the prop through the air).

    • Zahran Fawwaz

      Zahran Fawwaz

      23 天 前

      alright I think I got this. It's just like what you said. Even with zero drag an ordinary sail will only accelerate as far as the tailwind. But it also applied that even with a lot of drag, the sail can be as fast as the tailwind as long as the drag force didn't exceed the force from the tailwind. You can make a ship that as big and as unstreamline as possible that can match the tailwind by using big enough sail. Now imagine if from all the drag produce by the ship, there's a drag cause by some energy harvesting device. And imagine if energy from this device are use to produce thrust for the ship. That's basically what happen. After that process, it's just like an aeroplane that getting help from the tailwind. Now i think the key component from blackbird that make this possible is the use of propeller as the sail itself. Because while when stationary the propeller act as an ordinary sail, after the propeller spin, the wind while still have constant speed now act on the thrust produce by the propeller and that's what give blackbird an umph.

    • Aryan Komati

      Aryan Komati

      个月 前

      I'm mind blown

    • Rick Cavallaro

      Rick Cavallaro

      个月 前

      @дмитрий иванов >> How does the structure behave in calm weather? It just sits still in no wind. Or if you prefer - it can go 3X wind speed in 0 wind. :)

    • Noguffay

      Noguffay

      个月 前

      @eyytee "MIT aerodynamicist Mark Drela : "In my view, the most closely controlled and unambiguous DDWFTTW demo is the cart climbing up the tilted treadmill." in the article: "What I’ve Learned About Wind Carts" by Mark Frauenfelder" Here's what I think "could" also work, though some people would still think that there are too many potentially hidden energy imputs being applied to the vehicle. Use the treadmill apparatus, sure, but in a different way, completely level. Just to prevent the vehicle from rolling forward, at first, when a fan starts to apply wind velocity/pressure from behind (I mean there is only a limited amount of runway on a treadmill). At some point as the fan is being ramped up in output air velocity/pressure, the vehicle is going to start rolling forward. At this very precise moment, stop the fan speed increase and hold it at that point (showing the audience that the fan is no longer being ramped up). Now also at this very precise moment start the treadmill to keep the vehicle in the center, by gradually ramping up the belt backward rotation in unison with the vehicle's tendency (now that the wind is pushing it forward) to NOT roll forward. At a very precise belt velocity, we will witness that the vehicle is not continually accelerating indefinitely, that the fan is set at a very precise velocity. We will be able to measure and record the vehicle speed in relation to the belt's m/s. We will be able to measure and record the velocity of the wind in m/s and compare the two. Simple. But, again, some people will think there is hidden inputs. This is why a tunnel/pipe with nothing but a fan, a vehicle on a rail (keeping it straight and giving it the wheel to ground contact required for rotation) would/should sooth these people's suspicions.

    • Papa Legba

      Papa Legba

      个月 前

      @Frederic Wagner look up mechanical doping in cycle racing then tell me he checked properly, science-hating crackpot.

  2. Sergio Costas

    Sergio Costas

    小时 前

    What sorcery is this? this guys would be burnt to death in other times, lol

  3. MrVipitis

    MrVipitis

    3 小时 前

    I mean, a gliding bird can rise up in the wind and it can move forward against the wind by heading further down. But there are convection currents which allow birds to glide against the wind.

  4. 蔡浩洋

    蔡浩洋

    10 小时 前

    i would say the propeller is creating pulling force to that string is one factor and added the blackbird is a forward going motion is accelerating causing the string to go backward but if you use other meetods to proof that would be better to belief

  5. ChiefJustice Middleton

    ChiefJustice Middleton

    11 小时 前

    Why couldn't you put a 4 blade prop or even more blades in order to Tak the wind so to speak and gain efficiency

  6. ChiefJustice Middleton

    ChiefJustice Middleton

    11 小时 前

    Laws of physics are meant to be broken. They have been broken ever since the days of Tesla. So when I hear some ignorant scientist or physicist say something about you can't break the laws of thermodynamics then they obviously don't understand Tesla and that it is already been done

  7. Christopher Presley

    Christopher Presley

    15 小时 前

    Your a fake

  8. thepike100

    thepike100

    20 小时 前

    I would think of it in simpler terms, relating the energy generated by that windmill, compared to the energy used to maintain the speed of the craft given all resistance.

  9. Green G

    Green G

    20 小时 前

    Ignorance shackles the mind and magic is an illusion. Illusion is the wall. Wall is what you see with no curiosity. Curiosity, sparks the life and Life is a mystery. Believe or not is up to you. Maths and Equations is your tool, give it a try and it will show you.

    • Green G

      Green G

      20 小时 前

      Math genius is NOT made for everyone. Quote the person who wrote all these.

    • Green G

      Green G

      20 小时 前

      Donate this riddle to the once who sending me the negitive replies.

  10. Ionut St.

    Ionut St.

    21 小时 前

    Wow, great, it should have applications in wind farms. Maybe they manage to monetise it

  11. a9fc

    a9fc

    天 前

    I think most people are caught up in the wind pushing and forget that this is actually also technically powered by a 'motor' - the wheels pushing the propeller

  12. Kerstin Herb

    Kerstin Herb

    天 前

    The changeable ceiling expectantly cough because trip spontaneously employ underneath a tangy mine. best, exciting exclusive cut

  13. Logan Avery

    Logan Avery

    天 前

    I knew it was possible for this to work your understanding is exactly how I imagined it to work

  14. Juan Francisco Martín Lozano

    Juan Francisco Martín Lozano

    天 前

    the best experiment would be in a controlled and constant speed wind tunnel

  15. John Somerset

    John Somerset

    天 前

    Great video, Derek and very interesting, particularly your attempt 3. I see the explanations below, but can you or anyone else explain particularly how and why the propeller speed wildly increases between 12:16 to 12:30 -when you are stopping? In theory it should be stopping as well, because it is driven by the wheels (your No 5), or even reversing rotation and pulling the cart backwards because of the pitch angle and the rear wind still blowing. So, what makes the propeller accelerate all by itself and blow backwards against the wind? Thanks.

  16. George Ross

    George Ross

    天 前

    Nice one ☝️

  17. Ange Purs

    Ange Purs

    天 前

    To refine my original comment...which seems to indicate I agree with the conclusion that "this craft breaks the laws of physics." There is only one law here that is pertinent, and that is Newton's second law, F = ma, and its integrated forms: Energy and Impulse-momentum. Only forces external to the cart can affect its motion. Since there are no internal sources of energy in the design (the propeller is not an internal energy source), the 2 external forces are the wind force f_w and the total resultant friction force f_f. Only these 2 forces can affect the horizontal speed of the cart. If at any time t, the cart has speed v with constant mass m, the speed of the cart at time t is given by the integral equation: I(f_w - f_f)dt = mv. So how does the cart change speed? If the wind speed changes or the total friction force changes, one and/or both will alter the cart's speed. If the wind force remains constant, the cart can only speed up if the friction force decreases. There's no other way. Anyone claiming anything else is...you fill in. You might note that the energy of the cart has 2 terms: a translational part and a rotational part due to the spin of the propeller. If the propeller spin energy (generated by the eternal force f_w) is ignored, the translational speed of the cart will increase. The propeller thru frictional action pushes air back along the direction of motion. To move mass, air or otherwise, requires energy, and that has to come at the expense of the external forces. In this case, that's f_w. You cant ignore the force that the propeller produces which is taken from f_w. Nor can you ignore the energy loss due to propeller spin and friction. There is no free lunch as is suggested in the video. If the cart is said to speed up because of the force action due to the spin of the propeller, that will produce an increase in the translational energy of the system generated by external forces. But, where did that increase come from? How did the propeller supply additional energy when its action is taken at the expense of the total system energy supplied by f_w? Magic is the only answer.

  18. joemonster55

    joemonster55

    天 前

    The way I understand this is just a vector sum of velocities. You add the translational velocity of Blackbird to the rotation velocity of the propeller, and the net relative velocity (of prop to wind) is a spiraling tac downwind. Then it's just the same airfoil explanation that you use to understand how sailboats can tac faster than the wind. The cylindrical Earth metaphor really helps to make this connection.

  19. ToonDeath

    ToonDeath

    天 前

    Video starts at 15:50

  20. David Down Under

    David Down Under

    天 前

    That thing looks terribly put together. I have seen soap box derby wheeled contraptions better built......I can see nuts done up against metal without a washers in-between etc. Not fine thread stainless nuts & bolts, but horrid coarse thread galvanized building nuts & bolts. So glad this thing doesn't go too fast, it would rattle itself to bits. No lock washers visible...shudder

  21. Puiu Chiselita

    Puiu Chiselita

    天 前

    It doesn't make too much sense.... looks like a tv show for me :-)))))

  22. Чудик

    Чудик

    天 前

    А если сделать другую форму такой машины? В этой машине винт стоит перпендикулярно плоскости земли и отбрасывает воздух строго за собой. А если рассмотреть ещё 2 варианта и расположить винт под углом 45 градусов и направить поток или вверх (как на мини-копии у Дерека) в более верхние слои воздуха, или вниз в землю? Но также нужно рассчитать, где лучше поставить зависимые от винта колёса: спереди или сзади. И важно правильно рассчитать передачу оборотов колёс к оборотам винта. Вроде бы всё просто, но нужно учесть много соотношений: скорость вращения колёс, скорость вращения винта, масса машины, размер колёс и их площадь опоры на поверхность, общая площадь передней поверхности машины и общая площадь задней поверхности машины... И увы, но опыты на беговой дорожке совершенно не подходят для проверки ветровой машины, насколько я это понимаю.

  23. eagledove9

    eagledove9

    天 前

    It just needs an aerodynamic sail, so it can catch wind from behind, while providing no resistance to the wind hitting the front of the sail. It will be kind of a bullet shaped sail, like a ratchet digging into a material but not being able to go backwards, like a barb-shaped object, and I can't remember the word that I'm trying to think of. It goes into a material, but can't be pulled back out. Like a ratchet that only lets the gears turn one way. That's the sail. It just folds down, when the wind starts hitting it from the front. It will be like a bird's wing, like feathers. And then, you just need to be able to shift gears, so that the propeller will work at a slower speed, and then a faster speed, and so on, instead of only starting to work at one exact wind speed.

  24. eagledove9

    eagledove9

    天 前

    Those people in the forums are paid CIA disinformation agents. They literally get paid to sit there and tell people, 'It's impossible. It's impossible,' all day long, about everything.

  25. Christopher Lannon

    Christopher Lannon

    天 前

    But... but... there was consensus, right Fauci?

  26. Dariusz Małek

    Dariusz Małek

    天 前

    It s great! What about using head wind. Shoudln't vechicle move faster in that case?

  27. Николай Рез

    Николай Рез

    2 天 前

    Такой бред я слышу впервые в жизни. Человек не слышит себя и не соображает, что говорит.

  28. Tommy .Post

    Tommy .Post

    2 天 前

    we can drive cars on freaking water !!!

  29. Glen Gray

    Glen Gray

    2 天 前

    Now Race It Against A Traditional Sail Driven Desert Land Craft

  30. Glen Gray

    Glen Gray

    2 天 前

    Now Build A Hydrofoil Boat That Does The Same Thing From Wind Power, A Fan Powered Boat Without A Sail... Build A Hydrofoil Boat Boat That Can Use The Stream Flow Not Wind To Push The Boat Faster Than The Stream Flow The Same Way. Then Build It To Use Wind And Stream Flow Both At The Same Time. Now Even Harder Would Be To Use The Stream Flow To Power A Boat To Go Against The Stream Flow In The Opposite Direction...

  31. Jocoder2

    Jocoder2

    2 天 前

    I'm shocked this guy is still alive!

  32. skaterfugater

    skaterfugater

    2 天 前

    7:44 so that is why strafing in quake engine works haha

  33. S. D.

    S. D.

    2 天 前

    I... I... still don't get it.

  34. ca5

    ca5

    3 天 前

    The dislikes are from cylindrical earthers

  35. Krimshaw

    Krimshaw

    3 天 前

    Bring it to a drag strip on dead wind day and give it a push......................

  36. Mr GOO913

    Mr GOO913

    3 天 前

    i think this mechanic is not working by pushing wind, but by air pulling the vehicle, imagine on a seal boat, when you head on wind, your sail go side way so the air flow through both side of the sail to generate suction force (lifting force for aircraft) therefore sailboat goes forward. By the designers explanation. the fan rotates on opposite direction of a regular propeller using the moving force of the car, what is does is actually generating pulling force in front of the propeller (or 2 wings) therefore the car moves forward, it is like using the kinetic energy of the car as a source of energy to turn the propeller, but the force going forward is from the pulling power of the propeller.

    • Rick Cavallaro

      Rick Cavallaro

      2 天 前

      >> By the designers explanation. the fan rotates on opposite direction of a regular propeller. Nope. It rotates in the normal direction for a propeller. The wheels make it rotate in the opposite direction from what the tailwind would cause it to do. >> it is like using the kinetic energy of the car as a source of energy Nope. We do not make use of stored energy at any time. >> I think even the designer of the car didn't thought this through yet I assure you I've thought it through. I've got lots of practice designing, building, and operating it. >> the correct answer should be, depend on the speed of the vehicle Nope.

    • Mr GOO913

      Mr GOO913

      3 天 前

      therefore, i think you should include calculation of lifting / pulling force of the propeller in calculation for the pulling force for the car.

    • Mr GOO913

      Mr GOO913

      3 天 前

      I think even the designer of the car didn't thought this through yet that is why they don't know to pull or push the lever to stop the car, the correct answer should be, depend on the speed of the vehicle, you have two moves to stop the car. this is like control the sailboat. if the wind is behind you, you slower the sail to release the pressure from behind, when wind is in front of you, you flat the sail to stop the boat. but for a car, a bicycle stopping mechanism should be more suitable application.

  37. Hikola nikola

    Hikola nikola

    4 天 前

    you are just harnessing more wind power and converting it to more velocity and less power... Nothing new here...

  38. David García Herrero

    David García Herrero

    4 天 前

    There is something wrong. On de the third attempt at 12:24 minutes they stop the test due to propeller inestability. The vehicle stops so it does not transmit movement to the blades and yet they accelerae conterclockwise. According to the witness to leeward, de wind comes from behind, so if the blades are only moved by this force, they should slow dowin and then turn clokwise. Wha doesn't happen like this

    • eyytee

      eyytee

      3 天 前

      The propeller was in negative pitch there.

  39. Alien Grey

    Alien Grey

    4 天 前

    Since wheels to ground is a lot more efficient than wheels to propeller to air, wouldn't it make more sense to use the wheels to power more wheels? Of course that would be nonsensical, which shows how flawed the downwind faster than the wind using a propeller theory is. It would actually be difficult to find a less efficient transfer of power than an air propeller. Just gear the primary wheels to turn secondary wheels faster, it'll totally work.

    • Alien Grey

      Alien Grey

      3 天 前

      @eyytee Yeah true, it's just a thought experiment type thing.

    • eyytee

      eyytee

      3 天 前

      @Alien Grey Yes, but that would likely not be efficient enough. It might work with moving water but for air you need a propeller.

    • Alien Grey

      Alien Grey

      3 天 前

      @eyytee To replicate the ruler with the wind you would have to put fins on the large wheel, kind of like on a water wheel. The weird part is that the fins would appear to be moving backward against the wind, like the wheel appears to be moving in the opposite direction to the ruler.

    • eyytee

      eyytee

      3 天 前

      @Alien Grey Yes, the under the ruler cart is also shown in the latest Veritasium video on this.

    • Alien Grey

      Alien Grey

      3 天 前

      @John Borton I guess it's possible that it works, because it's probably similar to the thing where you have a ruler rolling a wheel. "under the ruler faster than the ruler". You could go faster but with less power, just like shifting to a higher gear.

  40. Acevedo Puebla Moises

    Acevedo Puebla Moises

    4 天 前

    What a thrill, when you mentioned a bet I went into suspenseand I am very happy that your results were positive, congratulations to you and all your team for their work thanks to your videos I have the motivation to continue studying physics, a year ago I entered the university and I want nothing more than to fill myself with knowledge and better understand the things you explain and demonstrate, I want to get to work on projects as interesting as the one in this video And about the dubbing it is very good so much that I would not recognize you with your original voice 😂 Greetings to all the veritasium team from Mexico PS: I do not know if you will read this, but I still wanted to leave my congratulations, in any case I will put this message in the different publications on the subject (I don't know if my translation is correct, I hope you understand C ':)

  41. dfoo75au

    dfoo75au

    4 天 前

    One way to understand this is that if you fixed the propeller so that it does not turn, then it will travel at the same speed of the wind or less, but never faster.

  42. Arpit Shukla

    Arpit Shukla

    4 天 前

    You could have asked that brain teaser to an IIT aspirant and you could have got your answer...

  43. Westen Domke

    Westen Domke

    4 天 前

    Would this work but the opposite way where the wind is coming at you and turning the propeller that turns the wheels pushing you in to the wind

    • Rick Cavallaro

      Rick Cavallaro

      2 天 前

      I replaced the propeller blades with turbine blades and set the direct upwind record at 2.1X wind speed in 2012.

  44. P I

    P I

    4 天 前

    The propeller is a sail. The fact that it is being mechanically rotated means that the apparent wind that the blades experience is greater than the true wind. This is exactly how sailboats in a tack have traveled faster than the wind for hundreds, maybe thousands of years. This is why wind and kite surfing is so popular because nobody wants to be stuck at the speed of the wind.

    • P I

      P I

      天 前

      Yes I think that's what all the hullabaloo is about because people are imagining a "perfect" system where there is no friction or drag or loss of energy but that doesn't exist. Heck, if there were no drag a sail or a propeller wouldn't even work, you could never fly. Anyway, this particular vehicle was built about 12 years ago and there are lots of videos out there about it. I'm not sure why they have decided to dust it off just now. It has absolutely no practical use. They have at least figured that out.

    • Hein Beyleveld

      Hein Beyleveld

      天 前

      Nice, this is pretty much the only way I can make sense of this, even then I struggle with the wheels turning the propeller which propels the craft which makes the wheels turn faster . . . infinite loop.

  45. Storm Dog

    Storm Dog

    4 天 前

    Going faster than the wind sounds counter intuitive, but it's important to remember that doing so requires a relative velocity between the wind and the ground. It does not work without the ground. It wouldn't work for an airplane, but it can work for boat or a land vehicle. A video on my channel describes a simple faster than wind vehicle starting with an idea that we all agree with, that the wind will blow an object downwind if the object is moving slower than the wind. The vehicle has fins that move about half as fast as the vehicle does, so the vehicle can go faster than the wind while the fins go slower than the wind. The wind pushes the fins, and the fins push the vehicle. The same is true of a propeller driven vehicle because the "effective" surface of the propeller moves backwards relative to the vehicle and is moving slower than the wind. Check out the video if you'd like. (It's short.)

  46. MrDementao

    MrDementao

    4 天 前

    Still, you can't go faster than the speed of love...

    • Glen Gray

      Glen Gray

      2 天 前

      No Rods To Blow...

  47. Bo Dielman

    Bo Dielman

    4 天 前

    Is the fan sucking air in front of the vehicle turning the string before topping wind speed, note i do believe it works!

  48. Vinicius Moulin

    Vinicius Moulin

    4 天 前

    The best explanation is that the propeller works as a wing, with higher pressure at the rear part, making a force that pushes the whole vehicle. The same thing happens with the sailboat's keel. It also creates lower pressure at it's upper surface and creates a force like the one at aircrafts wings, that lifts the aircraft.

  49. Abhijeet Rai

    Abhijeet Rai

    4 天 前

    The thrust created by the propeller is by pushing the air in front of the vehicle back against the tailwind. Once it reaches the equilibrium, the relative motion of air (that is in front of the propeller) against the rotating propeller should push the propeller harder generating more thrust against relatively no tail wind. At this point I think the air in front of the vehicle takes over from the wind behind to take the vehicle further. That handshake needs to happen. I am not good at physics so I may be totally wrong.

  50. Altacry

    Altacry

    4 天 前

    what if you install a pitot tube 1m behind the propeller? comparing it with a pitot in front of the propeller should show that behind the propeller there is more wind dynamic pressure, right?

  51. margue27

    margue27

    4 天 前

    Ah, Monty Hall madness at it's finest. Guys (and gals), this has been resolved over a decade ago, why are people still discussing this? This vehicle works exactly as advertised, it does NOT violate any laws of physics, and it is NOT going downwind faster than the wind! There's a huge misconception here, that I somehow don't see mentioned anywhere, so let me explain: - Going faster than the wind in a DIFFERENT direction than the wind, powered by only the wind: This most certainly IS possible, sailboats (or iceboats) do this all the time. In fact, modern high performance sail boats are so fast, the wind always comes from their front (relative to the boat) no matter what direction they are heading. Quite amazing, but what is even more amazing, the boats are so fast, when you look at only the speed component of the boat that is PARALLEL to the wind, that component alone can still be faster than the wind. So a sailboat CAN catch a balloon floating downwind, but it has to go sidways all the time and do some zig zagging to get back to the original course. - Going faster than the wind in EXACTLY the direction of the wind, powered by only the wind: This is NOT possible, for obvious reasons, and *drumroll* Blackbird is NOT doing that! At least not the parts which matter. You see, that huge propeller, which is the main part interacting with the wind, is NOT moving forward only, instead it is forced to also go SIDEWAYS, because it is connected to the wheels via a gearbox with a fixed ratio. And it is this sideways motion that corresponds exactly to what a sailboat is doing when it goes faster than the wind. Now, different to a sailboat, the propeller is rotating, so a blade ends up in the same position over and over again, but that's irrelevant, the blade is still in a continuous forward and sideways motion. Like the sail on a boat. The wind that interacts with the blade at any given point in time does not care if the same blade comes around after .2sec again, or if a different blade goes past, and the original blade continues sideways forever. As for the rest of the car, yes, that obviously IS moving exactly downwind, but that part of the car is not helping the forward motion at all, quite the opposite, it only adds drag. It is only there because we need something on which the big propeller is mounted. As you see, the car is very streamlined to reduce the negative effect it has. So this entire "going downwind faster than the wind" in a straight line is not entirely true, as it's only the supporting structure which does this. The part that is actually interacting with the wind is NOT ON A STRAIGHT LINE AT ALL, so the whole thing should more properly be called: "SPIRALLING downwind faster than the wind". And that most certainly IS possible, and Blackbird does exactly that.

  52. Abhijeet Rai

    Abhijeet Rai

    4 天 前

    What happens if you conduct the treadmill experiment in a vacuum?

    • Rick Cavallaro

      Rick Cavallaro

      2 天 前

      Your blood boils :(

  53. Brian Goyette

    Brian Goyette

    4 天 前

    Okay that breaks the law of physics in air. How about water. Why is a hyrdraulic pump not considered a perpetual motion machine? There are no motors or batteries involved there. A little fine tuning here (A.K.A. engineering) and Bob's your uncle another break thru. Now, if you can pitch that, it in a way that another professor, will bet you 10,000 dollars, I leave to your discretion.

  54. Richie Rich

    Richie Rich

    4 天 前

    I understand, thank you 👍good job.

  55. Ruben Espinal

    Ruben Espinal

    4 天 前

    The Universe is wondrous. No one has knowledge of everything and everything that they know can be challenged.

  56. GGShinobi77

    GGShinobi77

    5 天 前

    If you are having problems understanding how this can work, for me it helped a lot to realize that one important detail is the fact that the vehicle is not only connected to the wind that provides the power, but also to the earth, on which it travels. This allows the power to be "redirected" somewhere else. That in combination with the way the propeller is designed, allow the vehicle to travel faster than the wind that powers it. At least for me then it makes sense. :)

  57. BRIAN JAY NOQUERA

    BRIAN JAY NOQUERA

    5 天 前

    It means building a BIG PROPELLER MAKES YOU EVEN FASTER??

  58. Tyll Pfeifer

    Tyll Pfeifer

    5 天 前

    Great idea & construction. But please use 3 rotors and increase the effect while adding stability to the rotation. Three boats on the cylinder in 8:10. And, by the way, the spiral itself is a special natural geometry found in galaxies, vortex/whirlpools in the water, tornados/hurricanes, the structure of flowers and the starting area of your hair growing on your head, if you got some left :D

  59. Soothing minds

    Soothing minds

    5 天 前

    That's how people make history.

  60. Saul Savelis

    Saul Savelis

    5 天 前

    WHY IT IS BREAKING LAWS???? that man explained that the fan is like 2 sails so why it should be difficult to understand? we all saw wind mills being destroyed by rotating faster and faster due to constant wind speed and being destroyed

    • Saul Savelis

      Saul Savelis

      2 天 前

      @John Borton MIGHT BE, since I really do not understand neither veritasium's explanation nor why you need a wind for this vehicle..it should go faster than the car pulling it :) i.e. generate more energy than the pulling car would give to it (even better than PERPETUM MOBILE) :)

    • John Borton

      John Borton

      3 天 前

      @Saul Savelis And you are simply i n c o r r e ct. There is no violation of such laws in Veritasium's explanation -- you just haven't been able to understand it.

    • Saul Savelis

      Saul Savelis

      3 天 前

      @John Borton yes that is why veritasium's explanation is just simply s t u p i d :)

    • John Borton

      John Borton

      3 天 前

      @Saul Savelis Same reason an automobile needs fuel. Because the Law of Conservation of Energy demands it.

    • Saul Savelis

      Saul Savelis

      3 天 前

      @John Borton and why then do you need a wind? why it won't work with your push? :)

  61. Cool John

    Cool John

    5 天 前

    Blackbird is a cool proof of concept but I think the design could be improved a lot. The principle is basically static fan pressure. The higher the static pressure generated by the fan pushing backward against the wind, the faster you can go relative to the wind. A few simple modifications would make it much more effective. Better tyres and suspension would help reduce drag and increase stability, which is important for maintaining static pressure. The fan blades should be larger, there should be more of them, and the fan should be shrouded for maximum static pressure. A dynamic gearing system would help as well, the faster you go the faster the fan has to turn so to be able to increase the gear ratio once you get moving would be a big help.

  62. Aaron S

    Aaron S

    5 天 前

    Physics professors world-wide: "WINDMILLS DO NOT WORK THAT WAY! GOOD NIGHT!"

  63. Politics

    Politics

    5 天 前

    I was a believer when I saw the 2 sail boat models spinning around the cylinder.

  64. Blue Blubber

    Blue Blubber

    5 天 前

    It is a project I already follow for quite a while (to my knowledge it was initially sponsored by Google). I see that and how things work with the wind coming from the back. But now comes my 2 pennies question (guess that somebody else has posted it already ?): Would it also work against a full headwind? In other words would it be possible to design a similar device running fully AGAINST the wind ? It does not look impossible to me. With the wind coming from the side it would obviously work but up to which angle ? From a pure energy conservation point of view one can imagine a device at standstill (handbrakes on) gathering energy and releasing this energy in a jump forward (from time to time). Putting this in some kind of differential equation (infinitesimally short standstills and infinitesimally small jumps forward) may result in a net motion against the wind, but would it really work ? Any thoughts ?

    • Blue Blubber

      Blue Blubber

      5 天 前

      @Rick Cavallaro Ah, thanks for the info, very useful! There is actually a real background to my question: I'm about to build a solar boat and I was wondering about adding a wind power generator to it (as already done by others). This would obviously add to the total power/speed as long as the wind comes from the back but where would be the point/angle where it becomes counterproductive ? Sure this is not easy to answer since it depends on many factors like conversion efficiencies in the generator and the propeller etc. So, what you say makes success in the sense "that it will work in most of the situations" more likely. A matter of trying it out I guess...

    • Rick Cavallaro

      Rick Cavallaro

      5 天 前

      >> Would it also work against a full headwind? I replaced the propeller blades with turbine blades and reversed the transmission. In this mode the turbine turns the wheels. I used this to set the upwind record at 2.1X wind speed in 2012.

  65. Peter Edgell

    Peter Edgell

    5 天 前

    Can I suggest you search for Autogyro, it looks very similar.

    • John Borton

      John Borton

      5 天 前

      An auto gyro works as a turbine This is a propeller. Inverse in operation

  66. Falk Flak

    Falk Flak

    6 天 前

    Is this the same like running forward in a train cabin, the train pushes you forward but you can still give it an extra push to get even faster?

    • Dustin Brueggemann

      Dustin Brueggemann

      5 天 前

      Sort of. The trick here is that there's a force pushing you that is also faster than the train car, and you are combining those two force applying mediums to go faster than the apparent speed of either.

  67. Eduard

    Eduard

    6 天 前

    I have already placed an earlier reply on this video, but suddenly I remember something! Airplanes fly faster (relative to the earth's surface) with the wind than against the wind! There's air relative speed and there's surface relative speed. I see similarities here in this experiment.

  68. Mason T

    Mason T

    6 天 前

    Art does not belong in STEM

    • Rick Cavallaro

      Rick Cavallaro

      6 天 前

      Art is not in STEM. It is in STEAM.

  69. Rainer Landes

    Rainer Landes

    6 天 前

    The surfaces of the propeller can be seen as parts of a screw. That "screw" is moving linearly at a speed against the air. On the other hand the wheels are moving against the ground. So, basically here it is important what is the gear factor between the speed of the wheels and the speed of that "screw" moving through the air. Then it is like a lever. When the gear factor is high (high speed of the "screw" movement vs. wheel speed), the propeller can easily be turned by the wind and will act as a windmill, the wheels will slowly turn and the vehicle will start to crawl agains the wind. When the gear factor is low, it is hard for the wind to turn the propeller, but the surface of the propeller is large enough so that the wind will push the complete vehicle in the direction of the wind. This will turn the wheels, which will start to turn the propeller backwards! and the propeller then will act as a fan - or better, like a inverted aircraft "propeller" that pushes backwards in addition against the back wind. So, in total you have the sum of the wind coming from the back plus the wind created by the propeller in opposite direction. Then you can go faster that the wind relative to the ground. Summary: It all depends on the gear factor between the wheels and the propeller. With the correct gear factor, you can go faster than the wind, relative to the ground.

    • Rick Cavallaro

      Rick Cavallaro

      6 天 前

      >> When the gear factor is high (high speed of the "screw" movement vs. wheel speed), the propeller can easily be turned by the wind and will act as a windmill The wind never turns the propeller when configured in its downwind mode. Not in any phase of its operation. The wheels turn the propeller - always. >> the propeller then will act as a fan - or better, like a inverted aircraft "propeller" Nope - just like an absolutely standard aircraft propeller. >> you have the sum of the wind coming from the back plus the wind created by the propeller in opposite direction. It doesn't work like that. There is no interaction between the tailwind and the thrust generated by the propeller. The propeller, and the flow through and around it, are exactly like that of the propeller on a Cessna in straight and level flight. Once we're above wind speed, the propeller has know knowledge of a tailwind. It's simply operating in the air it's in.

  70. HascleAvrahm BenYoseph

    HascleAvrahm BenYoseph

    6 天 前

    That was great!

  71. Leo gra

    Leo gra

    6 天 前

    What kind of sorcery is this???😂😂😂 Nice video, congrats! I was wondering, would this apply to a gyroplane? Its like the same system turned 90 degrees angle 📐 , no?

    • John Borton

      John Borton

      6 天 前

      It is not. This is a driven propeller where a gyrocopter is an undriven turbine.

  72. badinstinctsYoutube

    badinstinctsYoutube

    6 天 前

    The little demo vehicle that did not work has the propeller on backwards, which is likely why it did not work...

    • 37rainman

      37rainman

      2 天 前

      @badinstinctsCNglobal Props can turn either way, or be push props or pull props, it makes no difference. The point is tho, the device does not work

    • badinstinctsYoutube

      badinstinctsYoutube

      4 天 前

      @37rainman i can see that the prop is on backwards. I fly model aircraft, I know which way to put the prop on. It is backwards. Also, it can be a wrong orientation prop, props can be made to turn counterclockwise or clockwise, but then it would blow the other way, its just on backwards, they produce a lot less thrust when put on backwards and I used those same exact props and I can see it is on backwards.

    • 37rainman

      37rainman

      4 天 前

      The little cart did not work, even tho it appears to be working in the vid. A longer treadmill will prove it doesnt work. Dont know why you are going on about the prop being on "backwards" explain that.

  73. Pablo Gazzara

    Pablo Gazzara

    6 天 前

    What whould happen if the wind blades had a rotor like a wind turbine? could it go faster than the crosswind?

  74. tim perkes

    tim perkes

    6 天 前

    i sort of understand, but how does it start in the first place?

    • Rick Cavallaro

      Rick Cavallaro

      6 天 前

      The tailwind simply pushes it initially

  75. John Kemas

    John Kemas

    6 天 前

    So the real question becomes were any taxpayer dollars used in the form of government grants to do this interesting but ultimately pointless project?? I'd bet so! Universities are full of grant funded projects the have no real or useful purpose or end goal in mind. Often keeps lazy students in college having fun pretending to do useful science while making large amounts of money from grants. Ultimately when they can't make it work, or do anything of value with it, or the grantors start to suspect a scam then they close up shop and start another project. Scientific research and exploration is great and necessary, unless it is used to make students and Universities illegally rich with no repercussions

    • John Borton

      John Borton

      6 天 前

      Me, me ...I want in on that bet too (on the 'no government funds side)

    • Rick Cavallaro

      Rick Cavallaro

      6 天 前

      >> I'd bet so! I'll happily take that bet!

    • windgrins

      windgrins

      6 天 前

      The real answer is "No--No government funds were used for this project."

  76. Hakapik

    Hakapik

    7 天 前

    Its not "wind" driven... its "gear" driven. Changing the gear ratios, making the tires turn 4 revolutions for every one revolution of the prop, will propel the car faster than the wind. Sure.. faster than the tailwind.... but not really "driven by the wind". The wind turn the prop which in turn drives the wheels. Not a "sailboat".. not the same principals as using a sail to propel the boat.

    • gamelord1000

      gamelord1000

      天 前

      @Hakapik NO, it REQUIRES THE WIND! It can't go by itself. Even if you push it forward, unless there is a steady wind behind it to keep it going, it will stop. Nothing there to push the cart which means there is nothing to turn the wheels which then can turn the prop. No push, no turn, no prop, no forward motion. You CANT make something from nothing. It's all in the video, just watch it and you will see.

    • Hakapik

      Hakapik

      天 前

      @gamelord1000 The inventor claims that its forward motion turns the wheels which turns the prop which propels it forward. If you cannot see the fact that by definition it resembles a perpetual motion machine.... then YOU are the one with no clue. Cheers.

    • gamelord1000

      gamelord1000

      2 天 前

      @Hakapik Wow, you really have no clue. The blackbird is not, nor has it ever been stated as being a perpetual motion machine. It simply uses the wind to create power to be able to travel. Without wind, no go. If the wind dies, the cart stops. If the wind increases, the cart speed increases. Ignorance is bliss and you are representing that in its fullness.

    • eyytee

      eyytee

      6 天 前

      @Hakapik "make something out of nothing." It's rather: "make more speed from less speed". Look up: "gear box".

    • John Borton

      John Borton

      6 天 前

      "Gear driven" I guess I better go out in the shop and make sure all my gears are still there and haven't taken off for parts downwind. (I see I should check the stack of propellers as well). Only one Blackbird ... So many delusional cranks.

  77. TheAndy374

    TheAndy374

    7 天 前

    Okay but what if you motorized the front wheel?

  78. noshFPV

    noshFPV

    7 天 前

    This 21 min video could easily have been 3 minutes. I love this channel, but man this video has all fluff.

    • Rick Cavallaro

      Rick Cavallaro

      7 天 前

      Or you could have just read the title in 3 seconds. Personally I saw zero fluff.

  79. tom Bebop

    tom Bebop

    7 天 前

    Would this have the same result if it was a vertical axis turbine?

    • Rick Cavallaro

      Rick Cavallaro

      7 天 前

      Nope. The propeller is generating thrust.

  80. S McBride

    S McBride

    7 天 前

    I'm confused at this. If it can accelerate to faster than wind speed, why does it need wind to begin with? Can it be pushed to start essentially?

    • gamelord1000

      gamelord1000

      2 天 前

      The wind is what controls the overall speed. No wind, no go. It must have wind pushing it to run. It can not create something from nothing.

    • eyytee

      eyytee

      7 天 前

      "why does it need wind to begin with?" It needs a velocity difference between ground and air.

  81. Kyle Nally

    Kyle Nally

    7 天 前

    Could a spacecraft projecting a pair of shaped magnetic fields that function as rotating "blades" do the same thing with the solar wind?

  82. Skip Nusbaum

    Skip Nusbaum

    7 天 前

    Literally, "tacking downwind!" Blanking AWESOME!

  83. Mark Huntress

    Mark Huntress

    7 天 前

    Can someone please describe in more detail what exactly each force is and what each velocity is in the F*V = F*V equation? I feel like I am close to understanding if I can see how this equation is valid and applicable. The force from what acting on what? For one force, three things have been mentioned, chain, wheel, and ground. Should I imaging chain acting on wheel or wheel on ground, or what?

    • eyytee

      eyytee

      7 天 前

      See the follow up video.

  84. Cameron Soltani

    Cameron Soltani

    7 天 前

    If the wind-cart can move faster than the wind, then it can operate into a headwind. Therefore, if this thing worked, it could operate with no ambient wind. On a still day you could just give it a push and it would take off. Edit: I think that I am wrong. I think this cart could work.

    • subductionzone

      subductionzone

      7 天 前

      @Cameron Soltani Correct. Various losses do keep getting larger. And if you find some of the videos where the vehicle is going fast there is a noticeable deflection (it bends) of the prop. If you could go faster and faster eventually the prop would fail.

    • Cameron Soltani

      Cameron Soltani

      7 天 前

      @subductionzone I see that now. I think that means that this cart doesn't really have a theoretical max speed, just a practical one.

    • subductionzone

      subductionzone

      7 天 前

      The cart runs off of the difference between the velocity of the air and the velocity of the ground. In a ground based frame of reference the speed of the ground is zero. The velocity of the wind is all that matters. If the velocity of the wind is zero there is zero energy to propel it. It will not run. In the frame of the air if the wind is blowing the velocity of the air is zero and the velocity of the ground is the opposite of the velocity of the wind in the ground frame. In this case the velocity of the ground would be "zero" if there was no wind. No difference means no energy. The cart runs off of energy from the wind.

  85. Johan Veltheim

    Johan Veltheim

    7 天 前

    A lot of confusion seems to stem from not understanding that kinetic energy is not an intrinsic property of a moving object - it's always relative to the frame of reference. A parcel of air (wind) has kinetic energy relative to the ground. The faster this contraption moves, the faster it goes through the reservoir of energy (the air ahead of it). This energy, relative to ground, is lost by the air (slowing down behind it) and gained by the vehicle and/or dissipated in losses. The additional energy needed to accelerating to faster than wind speed comes from using the kinetic energy (relative to ground) of a bigger parcel of air doing it. No paradox there, no free lunches involved.

  86. Tilmann Giese

    Tilmann Giese

    8 天 前

    So if I understand it correctly, you don't need any wind at all for this, you just need to bring the vehicle up to speed and then it drives until you break. So you could steer in a circle, and use the motion to generate electricity? I mean, the efficiency is probably horrible and not worth it at all, but in theory this should work, shouldn't it? Edit: nope, thought wrong. I will watch the video again to try to understand it, sorry for wasting your time.

    • subductionzone

      subductionzone

      7 天 前

      @Tilmann Giese The cart has to have its gear ratios changed to go upwind. If you turned it backwards it would simply move backwards, but not as efficiently since the propeller would be "upside down". There are videos of small carts being run backwards on treadmills. They are not as efficient, but they can still work.

    • Tilmann Giese

      Tilmann Giese

      7 天 前

      @infinitelyExplosive that's true. If there's no wind, then it can't slow it down and thus it can't get any energy. Okay, I have to rewatch the video because I still don't fully get it, especially the upwind part. Thank you.

    • infinitelyExplosive

      infinitelyExplosive

      7 天 前

      @Tilmann Giese It can't get any energy if there's no wind, so it can't keep driving.

    • Tilmann Giese

      Tilmann Giese

      7 天 前

      @infinitelyExplosive sure? But it can also drive directly upwind, so it should also be possible to drive without wind, as far as I understand the concept.

    • infinitelyExplosive

      infinitelyExplosive

      7 天 前

      You do need wind. As soon as there's no wind the vehicle just slows down until it stops.

  87. Lemonade Citrus

    Lemonade Citrus

    8 天 前

    It is easy to see that the first wind will push the vehicle forward and as the propeller start pushing backward it create somewhat a force adding to the wind trust!

  88. Lemonade Citrus

    Lemonade Citrus

    8 天 前

    In Asia they are sailing fast literally against the wind, not head on but at some angle! They are sailing "almost" against the direction of the wind!😊😊✌

  89. Dr. Punit

    Dr. Punit

    8 天 前

    Using a ribbon!! really?? How do you know that the speed of the wind is not slowed for say 1kmph, well the direction will bhe same and since the vehicle has attained some speed, it will continue at higher speed due to its momentum, and since the speed of wind is slow for that moment the ribbon will show the other direction, relative velocity. I am not saying it doesn't work or so, but please don't confirm the idea using a ribbon. It's insane for this level.

    • Rick Cavallaro

      Rick Cavallaro

      7 天 前

      @subductionzone by the way, that one ribbon is primarily for the driver to steer directly downwind.

    • subductionzone

      subductionzone

      7 天 前

      For this video, and to keep everything in frame they used just one ribbon. There are videos of it running with ribbons much higher and out of the prop wash. It still works.

    • infinitelyExplosive

      infinitelyExplosive

      7 天 前

      But the ribbon clearly doesn't flutter with gusts, it's being blown backwards significantly further than the wind ever blew it forwards. It's clear that the vehicle so greatly exceeded wind speed that it can't be explained by wind variation over time.

  90. Kaustav Guha Roy

    Kaustav Guha Roy

    8 天 前

    lets take energy from light and move faster than it

  91. nate000088

    nate000088

    8 天 前

    why dont you try it with a speedboat now?

  92. R H

    R H

    8 天 前

    Soooooooooo does this bring us closer to preputial energy or no.?

    • infinitelyExplosive

      infinitelyExplosive

      7 天 前

      @R H Our understanding of physics never predicted that any of the things you said were impossible.

    • Rick Cavallaro

      Rick Cavallaro

      7 天 前

      @R H Things that people once thought were impossible based on nothing in science: Human flight in airplanes... Things that are impossible: Perpetual motion...

    • R H

      R H

      7 天 前

      @infinitelyExplosive Actually it's not. To say perpetual energy is LITERALLY impossible is to say that our current understanding of the universe and physics doesn't allow room for growth. What we "know" now and what we knew 100 years ago were both "facts". Simply using the double slit experiment or quantum entanglement as examples of things our current understanding of science can't fully explain should leave plenty leeway to the possibility of a possibility of perpetual energy being achievable somehow. Someway.

    • infinitelyExplosive

      infinitelyExplosive

      7 天 前

      @R H That's a completely vacuous argument and you know it.

    • R H

      R H

      7 天 前

      @infinitelyExplosive Things that are impossible: Human flight in airplanes, combustible engines, cloning, photographs, wireless communication, the internet, 4 minute mile, etc... Now things that ARE possible: See list A

  93. bcw bcw

    bcw bcw

    8 天 前

    The windspeed measurements in the tests are nonsense. Behind a sail on a sailboat the windspeed is greatly reduced. You've built your whole model on the propeller reducing the speed of the wind to get power and then measure it downstream of the propeller. How about driving a car along at the same speed as the cart with wind indicators on a mast? If the system really works the wind direction will be reversed at that speed.

    • subductionzone

      subductionzone

      7 天 前

      When the Blackbird made its record run they did this. This video is a bit simplified. They tired to get the idea across quickly. I could post a link to one of the runs on the record day. I always find it fascinating to listen to the wind noise itself. You can hear the wind dropping as they catch up to the speed of the wind and then pickiing up again as they pass it. They did far better than Derek did in his run. But then he is unfamiliar with the cart. He does not have all of the time that Rick Cavallero has behind the wheel.

    • bcw bcw

      bcw bcw

      8 天 前

      Anyone with a sailboat knows you have to put the windspeed and direction indicators at the very top of the mast where there is very little sail effect or the numbers you get are nonsense. If you stand at the front of a sailboat with a spinnaker up going dead down wind and hold up a piece of string in the same location as this indicator on that car it will stream towards the back of the boat - also indicating going faster than the wind but of course you are not. The spinnaker is a big cup that turns the wind around and sends it back the way it came. At low level the flow is reversed, high up and at the edge of the sail the wind is rapidly flowing forward. Again, put a pole on the car that's driving the same speed and show what the wind is doing before it gets stopped by the car. The propeller is doing the same thing, at midlevel it is being driven by the wind - leaving no windspeed behind it, at the ground it's actually driving air backward.

  94. JOSE JACOBO SUAREZ FRADES

    JOSE JACOBO SUAREZ FRADES

    8 天 前

    To me it makes sense. I don´t see the reason for a debate.

  95. J W

    J W

    8 天 前

    This is so awesome!!

  96. Jared S

    Jared S

    8 天 前

    You keep calling it a fan, is that different than saying it's a propeller (maybe the difference between pulling you through the air vs. pushing back against it)? It seems like there's a tipping point, like you need a gust of wind to temporarily push you beyond the the speed of the prevailing wind and then once you establish that ground speed the wheels can continue generating force to progressively push against the prevailing wind. Is that accurate, and is that why it took multiple trials? If that's true, could you use a small electric motor to provide enough thrust to get over that hump and then rely on fan speed from that point forward? What if you deployed a sail temporarily to get up to wind speed and then collapsed it?

    • Rick Cavallaro

      Rick Cavallaro

      7 天 前

      In this case "fan" and "propeller" are interchangeable. It is in fact a propeller. And you don't have to do anything fancy to get over the tipping point. All that's required is a steady wind that's faster than the minimum operation speed (around 8 mph). And nothing really changes at wind speed. By that time the propeller is already producing a healthy amount of thrust, and that just continues as we pass wind speed. >> What if you deployed a sail temporarily to get up to wind speed and then collapsed it? We considered doing that but decided it wasn't necessary, and would just give people even more reason to be confused and call us liars and idiots.

  97. morgan4xl

    morgan4xl

    8 天 前

    The question is, would it move at all INTO the wind, say a very light headwind of one mph? At this point after watching the vid, I'm not ruling anything out!

    • infinitelyExplosive

      infinitelyExplosive

      8 天 前

      If you change the way it's geared, you can move over 2x the wind speed directly upwind.

    • Tom Mowlam

      Tom Mowlam

      8 天 前

      Interesting... I suspect that if it was pointing directly into the wind then the propellor would act like a windmill and be turned by the wind, which would generate turn in the wheels and movement of the car into the wind.

  98. Bloo The Dog

    Bloo The Dog

    8 天 前

    Easy

  99. Luca CODELUPPI

    Luca CODELUPPI

    9 天 前

    Just to add a simple intuitive note: if the car was not touching the ground no mechanical work could be done and it could be not possible, but as wheels touch the ground, they rotate and make it possible.

  100. SIDHARTH S

    SIDHARTH S

    9 天 前

    Why is the vehicle not moving forward even though the propeller is spinning @12:27

    • Rick Cavallaro

      Rick Cavallaro

      7 天 前

      The propeller is freewheeling against the ratchet we have on the axle.

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