Risking My Life To Settle A Physics Debate

29. Svi 2021.
6 223 708 Pregleda

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

▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
A HUGE thanks to Rick and Neil for letting me drive Blackbird. Check out Rick's HRex 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: hrex.infof... .

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

▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
References
Jack Goodman's HRex 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)

▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
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

▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
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

Komentari
  • 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).

    VeritasiumVeritasiumPrije 20 dana
    • I'm mind blown

      Aryan KomatiAryan KomatiPrije 18 dana
    • @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. :)

      Rick CavallaroRick CavallaroPrije 18 dana
    • @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.

      NoguffayNoguffayPrije 18 dana
    • @Fred Meister look up mechanical doping in cycle racing then tell me he checked properly, science-hating crackpot.

      Papa LegbaPapa LegbaPrije 19 dana
    • It still does not explain why the speed of the prop is accelerating instead of decelerating when the vehicle is slowed down.

      Joeri solJoeri solPrije 19 dana
  • "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." What about the energy that builds up in the chains and machinery? The momentum? I mean if I would start to accelerate this machine, the acceleration would carry over its point of neutral energy level momentarily and the go below the point of neutral energy and only to repeat these motions until it balances out. What im trying to say, what if you had this machine moving in a constant speed of x meters a second, without the acceleration force, would it still go above the wind speed? I get a little pullback-car feeling here, even trough you only drag a pullback-car back a small amount, it goes a long distance, because of the momentum built up into its gears? Did not the acceleration of the vehicle make it temporarily go above the wind speed? Because should not something going faster than the wind, apply a force on that wind, making it also go faster? So if I filled the deserts with these machines, they would not only have a waste product of friction, sound and heat, but would also make the wind go faster, making themselves go faster, making the wind go faster... upsetting maxwell. I really can not digest this... Give me a few days.

    Washemo AmadahWashemo AmadahPrije 18 minuta
  • So, is the answer to how it works as follows; 1) The vehicle acts as a sailing vessel until it reaches a critical speed OR wind speed (Whichever is less). 2) Once critical/wind speed is reached, the vehicle begins to operate as a propeller driven vehicle.

    Robert SwickRobert SwickPrije 40 minuta
  • This machine is an example of aether engineering. It is not the wind that is moving the machine.

    asollidasollidPrije 46 minuta
  • Do we have some explanation? On the moving belt I think it is going forward from rotational energy of propeler. On the ground it does not make sense to me, only from real wind, even when we going faster then wind. Otherwise, real wind would be useless there and I would speed up also without wind, just by pushing it by the car in the begining.

    Dado KomarDado KomarPrije 57 minuta
  • I love thought experiments like this. Trying to subvert the laws of thermodynamics to have something do something all people say cannot be done.

    Havoc MaverickHavoc MaverickPrije sat
  • Well, Derek made a big mistake here. But I'm sure he will make a new cool video admitting and analyzing the mistake. This is a valuable lesson to all of us that we all make mistakes from time to time.

    SergTTLSergTTLPrije sat
    • @John Borton Yes, I was aware of that bet at the moment of writing my initial comment to the video. And I expect Derek to lose the bet. The most important thing here is how he'll handle the defeat.

      SergTTLSergTTLPrije 11 minuta
    • @SergTTL You do know this is going to get settled in a very public way right? You know about the $10,000 bet between Derek and the UCLA Professor -- Bill Nye/Neil deGrasse Tyson/Sean Carroll signing on?

      John BortonJohn BortonPrije 51 minute
    • @SergTTL You'll see.

      John BortonJohn BortonPrije 55 minuta
    • @John Borton Why not? I'm sure Derek is smart enough to realize he is very wrong on this thing. And I'm sure he is brave enough to admit he was wrong.

      SergTTLSergTTLPrije 57 minuta
    • You're not going to like his next video on the topic then. :)

      John BortonJohn BortonPrije sat
  • I have a sudden urge to construct one of these, although I would make several design changes that should improve the efficiency.

    Dustin VanantwerpDustin VanantwerpPrije sat
    • Please do. The NALSA ratified 2.8x wind speed world record is there for the taking and will be the perfect yardstick to measure your efficiency improvements against.

      John BortonJohn BortonPrije sat
  • Cognitive neurosciences approach. American flags elicit. New technologies construct. Sciences awaken. Agricultural economics lesson. Technical disciplines control. Ecological economics enhance. Lib labs attain. Liberal economics adopt. International forensics skill. Traditional economics arouse. Evolutionary economics conceive. Several labs encourage. Understandable technologies enact. Small flags compose. Experimental neurosciences approach. Traditional economics contribute. Human sciences engender. Industrial technologies assemble. Specific technologies emerge.

    Rajat RoyRajat RoyPrije sat
  • Hear me out, I mean I may be stup, but can we do the same with sunlight? In space?

    Rajat RoyRajat RoyPrije sat
  • This is really inspiring! Could we regenerate enough power from water around a boat instead of regenerating it from wheels of this vehicle? So that for sailing downwind we could drop the traditional sails and employ a propeler?

    Pawel KedziorPawel KedziorPrije sat
  • 6:35 talking while its pretty windy. hahaha

    Korey MKorey MPrije 2 sati
  • I based my vehicle project in DT on this video

    Kar-Jun ThumKar-Jun ThumPrije 2 sati
    • just it harnesses the energy using storage, like a solar panel

      Kar-Jun ThumKar-Jun ThumPrije 2 sati
  • The gear ratio between the fan and the wheels...

    Jon SiaJon SiaPrije 2 sati
  • That looks a lot of fun.

    disarchitecteddisarchitectedPrije 2 sati
  • My brain is pain

    Ballsack69Ballsack69Prije 2 sati
  • Not new we got this in Holland

    come y bebe la vida es breve!come y bebe la vida es breve!Prije 2 sati
  • Somebody now do the same thing but with boats 🤔😊

    VALDI RADOVICVALDI RADOVICPrije 3 sati
  • free energy is here

    Zan belZan belPrije 3 sati
  • I love when the armchair experts are proved wrong.

    snarfbotsnarfbotPrije 3 sati
  • It’s like a cart from bad piggies

    TootkingTootkingPrije 4 sati
  • The mature july technically analyse because branch natively wipe besides a nutritious subway. inexpensive, panicky bridge

    Kevin BudzischKevin BudzischPrije 4 sati
  • The heady door speculatively stuff because ocean intracellularly groan times a beneficial almanac. taboo, witty crayfish

    Kevin BudzischKevin BudzischPrije 4 sati
  • Wow mind blown 🤯

    plebpunkplebpunkPrije 4 sati
  • Physics says no.

    calivaxcalivaxPrije 5 sati
    • Physics is totally down with this.

      eyyteeeyyteePrije 4 sati
  • +1 for accidentally proving the earth is flat (ish)

    Leon RaiLeon RaiPrije 5 sati
  • So what happens if you have more than 2 blades, would the increase in surface area add more top speed?

    Bok ChuakaBok ChuakaPrije 5 sati
  • I would think due to the viscosity of the air you would have an inelastic collision between the air and sails as well as drag from the pre-frontal area and body shape of a typical sailing craft. The energy in the wind applying pressure arrives at a net force of zero at the speed of the wind due to the summation of these forces, but this equilibrium does not mean that energy in the wind is not sufficient to push that weight of an object faster given the exposed area that the wind pressure acts on. By changing the shape (in this case of the sail), you can reduce the drag that is limiting the speed. Since the sail is a propeller, its shape produces less drag than the force produced by the effective area that the wind applies pressure to. After matching speed with the wind, the net positive force cannot accelerate the craft faster to a much higher velocity due to the stickiness of the wind, but since it is connected via transmission the the wheels and the propeller can rotate to match the relative speed of the wind, this stickiness can be overcome while maintaining an energy balance. The air behind continues to apply pressure parallel to the direction of the craft while the energy from the drag up front can be converted to rotational energy, which is transferred to the wheels. It experiences less drag due to the energy conversion and the portion of the drag converted to kinetic energy is used to drive the wheels. The craft then accelerates until the friction and drag become too strong, leading to net zero force.

    Dean WhiteDean WhitePrije 6 sati
  • Its like kicking oneself forward in flowing water in the direction of the flow, isn't it?

    S.Vidhyardh SinghS.Vidhyardh SinghPrije 6 sati
  • I have a question for those, who get science more than me: isn't this similar concept to what theoretical builds of Star Trek's warp engine use? Because am prstty sure it is :D Anyway, this is absolutely amazing and I love it! Thanks for making science even more fun than it is itself.

    Filip SochorFilip SochorPrije 7 sati
  • So can you make same thing on the water?

    Рэй ЧеховРэй ЧеховPrije 7 sati
  • this is alot simpler than it sound, it is just look at wrongly. engineer has been designing blade for planes and helicopters for decade, we have an entire science dedicate to getting more performance out of the blade without increasing it speed by adjusting its shape... clearly that must be doing something.

    lagrangeweilagrangeweiPrije 7 sati
  • Out of interest, why was the rear wheelbase asymmetrical? Is it to do with the torque of the rotating prop?

    stabarindestabarindePrije 7 sati
    • Yes, it's because of the prop torque.

      eyyteeeyyteePrije 3 sati
  • Just remember a child in Sweden putting a propeller on a car, in his sketch, and adults showing it and laughing... :-) Wonderful. I love your test.

    Martin GustavssonMartin GustavssonPrije 8 sati
  • Hi, im really impressed, there should be some tricky air currents around the propeller that could be an interesting challange for advanced airodynamic modeling software. The bad news: Here in Germany we lack such deserts..

    Urs KinzelbachUrs KinzelbachPrije 8 sati
  • Still not convinced...did you actually mesure the veichle speed and the wind speed or the floating string was the only evidence? Coldn't the fan just reduce the wind speed around the vichle and give wind a relative speed towards back, still the overall moving slower than the wind? Not saying it's fake, but it's so counter intuitive and this hipothesis would be way easier to accept...

    e ce cPrije 8 sati
    • @e c You're welcome. I have some animations which explain it on my channel.

      eyyteeeyyteePrije 7 sati
    • I feared that someone did reliable measurements... So I'm now left with the task of trying to understand it... Thanks mate!

      e ce cPrije 8 sati
    • NALSA already did the proper measurements. Search for "NALSA downwind record"

      eyyteeeyyteePrije 8 sati
  • Mind blowing, maybe at a higher speed than my mind itself.

    Alvise SembenicoAlvise SembenicoPrije 8 sati
  • This car is literally the thing the goblins used for their race in the shimmering flats lol wtf

    C: broskiC: broskiPrije 9 sati
  • Could they investigate the feasibility of a wind facing such chariot? Wouldn't that be totally impossible? Prove me wrong

    spolo123spolo123Prije 9 sati
  • Georgeos!!! Professor Lewin will love this !

    Dirk AnteunisDirk AnteunisPrije 10 sati
  • I immediately saw this guy and thought he was a flat earther. And then he said this: 8:06. *Wait, hold on a second...*

    Jordan FischerJordan FischerPrije 10 sati
    • hold on a second for two reasons: this guy's a genius, *and* he said "instead of a sphere" lol

      Jordan FischerJordan FischerPrije 10 sati
  • Great video

    Nagaraju ChukkalaNagaraju ChukkalaPrije 11 sati
  • There is no such law as conservation of speed, there is however conservation of energy/momentum. Momentum is mass times speed. by increasing the size of the aero-foil you deflect a bigger mass of air, and you gain more energy/momentum/lift without the wind speed having to increase through this deflection. Get a big enough aero-foil for the wight of your craft and you will be going faster than the wind. Physics professors should understand this.

    Anders BodinAnders BodinPrije 11 sati
  • The vehicle itself is the equivalent to the keel on a sailing boat. ie a resistance to the forward forces on the blades (Bernoulli effect)(assuming blades have profile of aircraft wings) Someone please correct me if I am wrong!

    Suzanne WilsonSuzanne WilsonPrije 11 sati
  • If the explanation at the end is how the car manages to move faster than the wind, then isn't it already detached from the original debate about a boat? He's saying the large fans are generating that additional thrust needed to push the car forward faster than the wind by pushing some air molecules backwards. That's completely different than a sail boat's design.

    Ben LBen LPrije 12 sati
  • Ok, I know there is a part of this video where the string and ribbon hanging on the front of the vehicle indicates he's going faster than the wind. I do not dispute this section of video. BUT here is what I believe happened: A gust of wind got him up to a good fast speed (but not faster than the gust), then the gust died away, leaving the car rolling along on it's own momentum. Since the wind gust has died, and the car is still rolling, of course it will now be moving faster than the wind. UNTIL IT COASTS TO A STOP. Also, if this thing can go faster than the air around it, why can't we just push it or pull it through still air so the wheels spin the prop and the resulting thrust keeps the thing running. Answer: that would be a perpetual motion machine---which does not and cannot exist. The only way I would believe this video is not a fake is if there is a chase vehicle off to the side of the prop car (so it won't interrupt the wind supply) and this vehicle has a very long, thin wand that goes up to the height of the propeller axle and releases a trail of smoke. Then we need a day with a steady wind and enough miles of level road to keep moving faster than the wind for several minutes. That way we rule out coasting.

    Brian BairdBrian BairdPrije 13 sati
    • > "why can't we just push it or pull it through still air" Read the pinned comment. > "if there is a chase vehicle off to the side of the prop car" NALSA did that for the record runs. Google "NALSA downwind record" > "That way we rule out coasting." This was ruled out by the NALSA rules: No stored energy can be used for propulsion. The vehicle has to accelerate while being above current windspeed.

      eyyteeeyyteePrije 6 sati
  • Even after the explanation, I still cannot wrap my head around how the energy in conserved? Till the moment the craft reaches the wind speed (the external force) it makes sense that the craft is accelerating. However, after reaching the wind speed, where is the power coming to spin the propellers faster than wind speed? As per explanation, the power after this point (for accelaration) is generated by the craft! If someone can explain further, it would be of much help!

    Sanniv BhaduriSanniv BhaduriPrije 13 sati
    • Where the power comes from depends on the reference frame you pick to do the analysis. But in any frame the velocity difference between air and ground (true wind) is being reduced.

      eyyteeeyyteePrije 11 sati
    • It is still slowing the wind relative to the ground when above windspeed. Energy lost there will balance the energy gained by the accelerated cart plus losses.

      J ModifiedJ ModifiedPrije 13 sati
  • The zealous columnist covalently laugh because ease oceanographically alert versus a zealous llama. sore, nutty train

    Kris HannaKris HannaPrije 14 sati
  • I dont understand how people dont get it LOL I mean the way you explained it, is so clear and even with an experiment XD

    Franklin YaoFranklin YaoPrije 14 sati
  • Now what about the gears? The fan could be a fan or a propeller, but with enought gears and little force reduction, they could drive against the wind?...

    Don Omar RamiroDon Omar RamiroPrije 15 sati
    • They already went directly upwind at 2.1 windspeed with that cart.

      eyyteeeyyteePrije 11 sati
  • Rogue scientists.

    Student A FakeStudent A FakePrije 16 sati
  • This is essentially a form of gearing between the input and output power to optimise the forces and speeds to the vehicle requirements. A couple of ways I think this can be compared to a "spinnaker going with the wind" (which is limited to below the wind speed, but can usually provide more than the required force): 1. Use the spinnaker to pull a vehicle up a hill at close to the wind speed, then roll down a hill at higher speed. This could average out well above the wind speed. 2. Have the spinnaker out in front of the vehicle on a long rope, and wind the rope in around the axle as the vehicle moves. It will travel faster than the wind until the rope runs out.

    DumHedDumHedPrije 16 sati
  • Hover crafts ride on a cushion of air. This cart is being propelled by a pocket of air. Totally awsome!

    TonyTonyPrije 16 sati
  • Great video. But I think the propeller on that little model is on backwards

    Elliott KemberElliott KemberPrije 16 sati
  • Did you just say 2.8 times the wind speed or approximately 100% growth that is Euler's constant...!!!

    Raghavendra GowdaRaghavendra GowdaPrije 16 sati
  • Forever grateful to *sparkplug lite* via Instagram he recovered mine car so glad ...he is the best%

    Daniel ZachariahDaniel ZachariahPrije 16 sati
  • Forever grateful to *sparkplug lite* via Instagram he recovered mine car so glad ...he is the best%

    Daniel ZachariahDaniel ZachariahPrije 16 sati
  • Around the 12:14 mark, the prop begins to spin out of control, even as the vehicle slows down. Yet, it is still spinning counter to the wind direction. What could have caused this?

    Mac DerscheidMac DerscheidPrije 16 sati
  • the thing that i can't wrap my head around, is in its design. You say that the propeller portion of the vehicle acts as a fan that pushes air. Now i understand that it seems that there seems to be some control in the tilt of the props, but the structure of the vehicle just makes it look like the fan would be pushing air in the same direction of the car, when in reality, it is pushing air backwards?

    CoachZedCoachZedPrije 17 sati
  • Jesus loves you

    300pzl300pzlPrije 18 sati
  • The apathetic brick radiologically shelter because vulture prenatally heap despite a muddled smile. magical, thoughtful veterinarian

    OprahsKanklesOprahsKanklesPrije 18 sati
  • The thoughtless library electrophoretically flow because sailboat philly battle until a vast gray. shrill, superficial parade

    PercyPercyPrije 19 sati
  • But how much weight can it push? Realistically could we see one one running on a 50ft cruising yacht? Would be amazing for sailing with the wind if it worked, could mount it on the mast and put into storage when not needed.

    royal decree for the church of muskologyroyal decree for the church of muskologyPrije 19 sati
  • Boy looks so “risky.”

    NyarlathotepNyarlathotepPrije 20 sati
  • Ofc thats phisically possible. Btw which moron designed that propeller?

    John DoeJohn DoePrije 20 sati
  • Although like many things in physics this seems counter-intuitive I don't think it takes too much thought to see how it might work. The propeller is pitched - so it's at angle to the wind, just like a sail is when it's generating lift (when the boat is close hauled or in a close reach). This means that the analogy to a sailing boat running before the wind is false (it would be true if the propeller were perfectly flat) - although the crafts orientation looks like the boat, it's not - the propeller is acting to generate lift just like the sail (because it's twisted or pitched).

    Geeky PeekGeeky PeekPrije 20 sati
    • The analogy is not to a sail boat running before the wind, but rather to a sail boat on a broad reach. That's what is shown in the 'cylindrical earth' animation.

      John BortonJohn BortonPrije 18 sati
  • That whole thing proves one thing, that is more important that some may realise: logical and obvious are two completely different things. It is logical that it works, but you have to logic pretty hard to get behind it. It is absolutely not obvious and it neither is intuitive. Logic doesn't have to be intuitive.

    NochSoEinKaddiFanNochSoEinKaddiFanPrije 21 sat
  • I have three questions please: 1.) What if the propeller was attached to the wheels with a ratchet such that if the wind pushed the vehicle it would move forward but if the wind died down the momentum of the vehicle would not continue to turn the prop. 2.) What if, hypothetically, the resistance of the vehicle itself to the wind was zero from all directions. So the wind could only push the propeller and only the propeller could move the vehicle. 3.) In the cylindrical earth diagrams the ships are moving at angle to the wind so they are travelling along the long edge of a triangle. This would seem to explain why they are moving "faster" than the wind at angle but in terms of movement in the direction of the wind they are moving at the same speed (in other words they are moving faster but some of the movement is lateral). Is this correct?

    Sam WheatSam WheatPrije 21 sat
    • @Sam Wheat Attaching a sail (spinnaker like) to the craft would help it get up near wind speed faster, but would then become useless the closer one got to wind speed. At vehicle speeds above the true wind speed, any such sail would add drag and impede the vehicle from traveling faster than the wind.

      John BortonJohn BortonPrije 20 sati
    • @John Borton Thanks for your reply. After reading more my question 1 was exactly backwards - the wheels turn the prop - not the other way round. My question 2 relates to the wind pushing the vehich vs the prop. Stated differently: Why does it not make sense to attach a large sail to the vehicle to maximize transmission of power to the wheels?

      Sam WheatSam WheatPrije 20 sati
    • I can answer 1 and 3. I'm not sure I understand your question #2. 1: The vehicle has the exact ratchet clutch you describe. It's there for two reasons: A) To demonstrate to NALSA (who monitored and ratified the FIA world record) that no stored energy from the propeller could be used to back-drive the wheels and accelerate the vehicle. B) To ensure that when braking the vehicle, it could be stopped without having to also brake the prop to a stop. This reduces an already long stopping distance. 3: High performance sailing craft can indeed move faster downwind (while traveling on an angle) than the wind. Meaning the downwind component of their speed can exceed the speed of the wind.

      John BortonJohn BortonPrije 21 sat
  • So the way i understand is the following: the wind always puts enough energy into the vehicle to bring it up to wind speed, no matter what the mechanism causes in friction and stuff. It is not a closed system, but always fresh energy coming in from the wind. Once you reach windspeed, you have "still air" around your fan. When the fan comes down, it bumps into air and gets pushed as much foreward as the air gets pushed back. Any Energy that is needed to rotate the fan against the resistance of "still air" is replenished by the remaining wind behind the vehicle. Like i said, it is an open system with a constand feed of energy into it, that is why it makes sense to me. Once you loose wind, you stop. It would ony violate the conservation of energy, if it would continue driving without wind. I wonder if you could make it so that the air resistance from the front is lower than from the back, creating a small sail and that way putting more power into the fan, making the vehicle even faster down wind.

    NochSoEinKaddiFanNochSoEinKaddiFanPrije 21 sat
  • The variable pitch prop is the key to the entire setup

    INTEGRALPHYSICSINTEGRALPHYSICSPrije 21 sat
    • Nope. The vehicle didn't have a variable pitch prop until it had already run multiples of windspeed. This feature was added later.

      John BortonJohn BortonPrije 21 sat
  • Wear a mask!

    dragonDScriptdragonDScriptPrije 22 sati
  • The raspy bowling affectively reach because drive coincidingly confess past a simplistic south korea. substantial, shut mint

    Tula BairdTula BairdPrije 22 sati
  • It's a sail that moves and gives extra push.

    Carbon2861996Carbon2861996Prije 23 sati
  • LETS BUILD AN AIRPLANE AND START PULLING IT UP AND RELEASE AFTER! LETS DO A PROJECT!

    mussionarymussionaryPrije 23 sati
  • Soooo cool, Would this work if you split 1 big wind mil to 4 smaller? There by not have the wobeling....

    E EE EPrije 23 sati
    • @J Modified Thank you

      E EE EPrije 13 sati
    • The wobbling was due to a temporary technical issue. In general one large prop will be more efficient than four small ones that sweep an equivalent area, plus you'd need more linkages. On the other hand, counter-rotating props or pairs of props would eliminate one-way twist on the main frame.

      J ModifiedJ ModifiedPrije 13 sati
  • I'm wondering if we could put one of these things on a track, have it propelled around in a circle by a fan, or set of fans, generate energy, loop some of that energy back to continue powering the fan(s), and then use the excess energy...

    Mark SMark SPrije 23 sati
  • The coordinated trunk ethically mourn because seashore evidently imagine versus a direful root. evanescent, well-to-do beast

    Ruth DunnRuth DunnPrije dan
  • So if prop can take all 100% of energy from the wind... What will be forward acceleration of the vehicle?

    Suresh RavikumarSuresh RavikumarPrije dan
  • It’s funny how he wears a helmet but doesn’t buckle it like idiot it doesn’t do you any good

    Wesley FreyWesley FreyPrije dan
  • Civility ya jerks,civility

    enochian sevenenochian sevenPrije dan
  • The womanly idea timely exist because toast cytopathologically rain vice a deserted magician. windy, billowy dust

    Maggie HernandezMaggie HernandezPrije dan
  • I don't think you have to explain it. Just prove that it's possible. There are countless scientific discoveries where the discoverer did not fully understand what he/she accomplished. Let the physicists do the math.

    David MDavid MPrije dan
  • im sorry Derek but your explanation "If we apply this power to the fan, it can create a force of F = P/V = 1200W / 2m/s = 600N" cant possibly be true because the force would tend towards infinity if the difference (vehicle speed - windspeed) approaches 0.

    S1nwarS1nwarPrije dan
    • No, because the efficiency of the propeller also goes to zero, when V=W, so the thrust converges toward some finite value called "static thrust". But that's irrelevant to the situation which Derek explains, where V>W.

      eyyteeeyyteePrije 22 sati
  • 🤔

    Inshaf AhmedInshaf AhmedPrije dan
  • So does that mean the prop is acting as a compressor second handedly to maintain air pressure?

    budrow1999budrow1999Prije dan
  • Idk why.... I keep imagining Charlie's voice (penguinz0) "SCIENCE SAID IT COULDNT BE DONE!!!!"

    siddhanth ravichandransiddhanth ravichandranPrije dan
  • How much faster it can possibly get ? What will be the bottleneck in that case ?

    Chetan RajputChetan RajputPrije dan
    • max_speed = wind_speed / (1 - efficiency)

      eyyteeeyyteePrije 22 sati
  • I won't push back. The vehicle is doing enough of that already :D Seriously, this is amazing. Thanks to all of you.

    unknownunknownPrije dan
  • The joyous grey aesthetically chop because business aboaly develop sans a male bagel. deafening, known relation

    brendy isabel santiago ullerobrendy isabel santiago ulleroPrije dan
  • But this time youre false. Bin von dir sehr Inspiriert, du machst eine tolle Arbeit und bringst uns alle weiter. Mit ispiration. Und genialer Wissenschaft. Aber es ist eine Optische Täuschung. It depends on potentional Energy, and in this case also Time. And a perpetuum Mobile is real, but the Energy to build some, is higher than it will produce.

    L33Th1nK1ngL33Th1nK1ngPrije dan
  • Your prop is on backwards in all of your animations

    nickj384nickj384Prije dan
  • This is nonsensical. If it is propelled in zero relative wind then it should work with no actual wind at all right?

    Mikey MasticatorMikey MasticatorPrije dan
    • @Rick Cavallaro you still here, trolling everyone who points out your BS? psycho.

      Papa LegbaPapa LegbaPrije 14 sati
    • @Mikey Masticator You think the fact that it can go 0 mph when the wind is 0 mph makes it a perpetual motion machine? I think you're being overly generous.

      Rick CavallaroRick CavallaroPrije 19 sati
    • @Rick Cavallaro That makes it a perpetual motion machine.

      Mikey MasticatorMikey MasticatorPrije 19 sati
    • @S1nwar They are claiming FASTER THAN the wind heading downwind!

      Mikey MasticatorMikey MasticatorPrije 19 sati
    • a sailingboat can also travel as fast as the wind. does a boat work without wind :p? dont confuse yourself.

      S1nwarS1nwarPrije dan
  • Now we can use this type of concept on Sun Space Ship Sails to travel @2X the speed of light.

    hunterssportshunterssportsPrije dan
  • The common random intrestingly wink because fire pathophysiologically level like a overwrought diving. kindly, fuzzy musician

    Sandra CashSandra CashPrije dan
  • All these years and planes have had the props the wrong way round.

    Mark FreemanMark FreemanPrije dan
    • If the objective of the plane was to 2.8x the windspeed to trudge along the ground, then yes, Wright Bros should have tried their hand at fame via youtube comments ;-)

      squaresenseisquaresenseiPrije 12 sati
  • It's the same reason why a kite flies, isn't it? If you let go of a the line, the kite will immediately start falling to the ground.

    Luobo MuLuobo MuPrije dan
  • My 2nd watch of the summary explanation and I have a complete moving demonstration in my mind. You have to think of it in an inertial frame of reference and keep in mind how the air is moving in relation to the ground.

    GetMoGamingGetMoGamingPrije dan
  • this is realy amazing .. I love the thought process behind it and how genius it is :O

    JsonKodyJsonKodyPrije dan
  • I wonder if it can make a plane fly faster then the tail wind?

    DavidDavidPrije dan
  • I want a toy version of this.

    GetMoGamingGetMoGamingPrije dan
HRex