Risking My Life To Settle A Physics Debate

29.05.2021
6 125 643 Näkymät

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 FIboth 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: fiboth.infof... .

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

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References
Jack Goodman's FIboth 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

Kommentteja
  • 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).

    VeritasiumVeritasium17 päivää sitten
    • I'm mind blown

      Aryan KomatiAryan Komati15 päivää sitten
    • @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 Cavallaro15 päivää sitten
    • @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.

      NoguffayNoguffay16 päivää sitten
    • @Fred Meister look up mechanical doping in cycle racing then tell me he checked properly, science-hating crackpot.

      Papa LegbaPapa Legba16 päivää sitten
    • It still does not explain why the speed of the prop is accelerating instead of decelerating when the vehicle is slowed down.

      Joeri solJoeri sol16 päivää sitten
  • The wind indicator pointing backwards does not mean the vehicle is going faster than the wind

    marc prezeaumarc prezeau9 minuuttia sitten
  • I really want to learn physics but I am afraid I won't understand ;-;

    Fola DodoFola Dodo34 minuuttia sitten
  • Just wanted to say huge props (hah) to the drone operator, beautiful shots from that tiny little thing

    zuikatsuzuikatsu53 minuuttia sitten
  • ok so can we generate infinite energy from it if this all working exactly fine. wouldnt this be the end of energy crisis......

    Mohesh GuptaMohesh GuptaTunti sitten
  • How is he "Risking his Life To Settle A Physics Debate?" xD this is bot risking your life

    Jessica EvansJessica EvansTunti sitten
  • Based on the motion of the blades, they indeed push the air backward. As you explained you should experience a propulsion from this motion, but I also believe you should have a difference in air pressure at the front of the blades, allowing the fan to be sucked forward, and increasing your speed further. I might be wrong, as it is an area of physics that twist my mind a bit…. NOTE: Rick and Neil really need to use 3 or 4 blades to stabilise the fan while it is spinning. Centrifuges spin AT LEAST with 3 arms for that reason 😊 engineers can chose other materials to balance the increase in weight of the overall structure if necessary.

    Adrian Z.Adrian Z.2 tuntia sitten
  • Only wind relative to the sail surface is important. Multihull Americas Cup hydrofoil boats are exceeding wind speed down wind. Once on the foils, low drag, high speed, and as you turn down wind(ish) the sail has relative wind toward front despite true wind behind. Crazy to see them going 30kts in 12kts wind.

    Bob Roberts (Down2TheC)Bob Roberts (Down2TheC)2 tuntia sitten
  • Clowning on physics professors isn't an achievement you get everyday

    soiung toiuesoiung toiue2 tuntia sitten
  • Clearly there’s an electric motor in it

    FlatWorldJomhuriRegime88FlatWorldJomhuriRegime882 tuntia sitten
    • If they would've did something like this in HS I would've liked physics more 😂

      soiung toiuesoiung toiue2 tuntia sitten
  • Tier 2 of this tech tree: FTL travel.

    HyShadeHyShade2 tuntia sitten
  • He lost all the flat earthers at the point he had sailing boats on a cylinder.

    tomehosttomehost3 tuntia sitten
  • The auspicious editor bailly fear because knee steadily desert alongside a harmonious deficit. trite, military armchair

    な だいな だい3 tuntia sitten
  • is there a way my pants blown faster than my fart exit from my butt?

    Aldien WannugaAldien Wannuga3 tuntia sitten
  • I want to Help. I have an idea to progress the acceleration.

    airtadeoairtadeo4 tuntia sitten
  • At 8:30 the simulation shows the wrong propeller rotation for forward travel. And also a backwards propeller to boot.

    imd12c4adviceimd12c4advice4 tuntia sitten
  • Everyone has misunderstood what is really happening here. This wouldn’t work if the earth was flat but because it is curved once you move off the top peak of the curve it is all down hill. This allows you to keep accelerating until you reach the South Pole. Simple and in line with the laws of physics.

    Ch LopeCh Lope4 tuntia sitten
  • Well its not quite perpetual motion, cause you pull energy from wind

    MirageMirage5 tuntia sitten
  • Could there be a way to apply this to gravity / space travel to go further then the speed of light or is it potatoes and tomatoes?

    Cosmic MorningCosmic Morning5 tuntia sitten
  • Yesterday I posted an answer on Quora to the question: "Could a sailing boat outrun a balloon?" My Answer was, in general NO, and postulated an unlikely situation in which it could happen. I will now have to Eat My Words and humbly admit that I have seen it with my own eyes. It is not a boat but it IS a wind-powered vehicle. You, Sir, are a genius! (Now to figure out how it works...)

    Chris CarterChris Carter5 tuntia sitten
    • Check out the latest New Zealand America's Cup boats. These boats regularly out run the wind, just not directly downwind.

      Bill CarrBill Carr37 minuuttia sitten
  • I love your explanations, as they’re just dumbed down enough that mostly everyone understood. Though it’s intellectual enough that the more intelligent people don’t feel patronized. That being said, I thought it was like the one myth busters episode. Where they tested if you walked or ran in the rain. Which one would get you more wet. Where running actually got you more wet. As you’re running into more rain than you would be if you walked. As only so much rain (wind in this case) can impact you in that area. So once you meet the speed of the wind. The same amount is hitting you repeatedly, though if you take the cross wind. You get more as you’re entering a new area for it to impart some energy into.

    Setsura- samaSetsura- sama5 tuntia sitten
  • Never do I write YT comments. But this blew mew more than any other video out there. Love your work. It never ceases to amaze me :)

    saket vatsasaket vatsa5 tuntia sitten
  • Maybe propeller is on height which make drive faster than the string attached to bottom because wind is faster when the height increases or may be momentum get added up

    Ankit KumarAnkit Kumar6 tuntia sitten
  • I wish I could meet you just because the knowledge I would gain in that short amount of time would be amazing. Thanks so much for this video!

    NathanNathan6 tuntia sitten
  • I thought of a 3-part brain teaser based on the downwind cart. Maybe it's trivial and flawed, but it makes you think about the interactions of the cart with the wind. Mount a mechanical anemometer at the top of the cart. a) When the cart is moving relative to the ground at wind speed, what would the anemometer read? b) When the cart is moving relative to the ground at wind speed, is the true wind (the wind from the atmosphere) still pushing on the anemometer? c) Now place the anemometer on the cart so it can only measure the true wind. Place a second anemometer on the cart so it can only measure the relative wind. With the cart moving at wind speed across the ground, what would be the sum of the speeds measured by the two anemometers, ignoring energy losses?

    David Woodside (Wiseacre Dave)David Woodside (Wiseacre Dave)6 tuntia sitten
  • If they would've did something like this in HS I would've liked physics more 😂

    J MorrisJ Morris7 tuntia sitten
  • Sort of like drafting in motorcycle racing. Another idea would be to consider a shroud for the fan to increase efficiency.

    Sheldon CusterSheldon Custer7 tuntia sitten
  • In theory would it be possible to ride it against the wind?

    Winston (0090)Winston (0090)7 tuntia sitten
  • I have watched the video and read read lots of these comments - some very instructive. My first thoughts were... this is impossible... can't get something for nothing! Who needs an engine if you can go faster than the wind! Of course it is possible the vehicle has a hidden power source but I'm assuming not. At the start, when the vehicle is a rest, it is blown by the tail wind (say 10kt). The cart and prop are acting as a sail. The drive is disengaged so there is no backward force from the prop to wheels. One comment said why not use a sail! It could be thrown overboard once the cart is moving at a certain speed but I don't like the comparisons to a sail boat. The wind can accelerate the vehicle to a maximum speed of (almost) wind-speed. Then if we engage the prop - this will certainly brake the wheels and thus slow the vehicle. Then wind tries to accelerate the vehicle back up to wind-speed. Meanwhile, the prop is pushing air backwards (say 2kt relative to the prop). So the wind-speed at the prop (relative to the ground) is now 8kt... so the wind can give us 2kt more up to 12kt. Then we are in a positive feedback loop until losses (drag/friction) balance gains. Is this how it works?

    Kenneth HoadleyKenneth Hoadley7 tuntia sitten
  • They should add variable sails to the sides of the prop tower that can be deployed at the start, then drawn as the vehicle speeds up.

    Sheldon CusterSheldon Custer7 tuntia sitten
  • by the way does he use any fule well if he doent then we have infinte enrgy broooooo

    Shrawan DhawaleShrawan Dhawale8 tuntia sitten
    • Yeah, sailboats are fake - they all have hidden motors.

      J ModifiedJ ModifiedTunti sitten
  • The squealing consonant arguably inject because mouth secondly wriggle worth a sassy cooking. ordinary, permissible seaplane

    Lavonia LauriLavonia Lauri8 tuntia sitten
  • He's got no shades!!

    Subtle EntitySubtle Entity8 tuntia sitten
  • What’s the theoretical maximum ratio between wind speed and vehicle speed? Is there a way to calculate? Is it 3.14159....?

    MrRickkramerMrRickkramer8 tuntia sitten
    • max_speed = wind_speed / (1 - efficiency)

      eyyteeeyytee8 tuntia sitten
  • what about a transmission?

    Tom GrüberTom Grüber8 tuntia sitten
  • So, you had a nice downhill drive :)

    Jan KlasJan Klas9 tuntia sitten
    • @Jan Klas // "Dear John.. I'd advise you go google on 'emoticons, what do they mean and what are they used for'."// // "Usually people who feel the urge to advice someone, have some kind of authority. Usually. Not always. QED."// I'm glad you finally solved your problem and figured out the futility of your actions. Dumbass.

      John BortonJohn Borton23 minuuttia sitten
    • @John Borton Usually people who feel the urge to advice someone, have some kind of authority. Usually. Not always. QED. If you were to stupid to understand my remark was a joke (the smiley might have given that away, one would say) you're not going to understand anything. Good luck with that.

      Jan KlasJan Klas2 tuntia sitten
    • @Jan Klas I'd advise you Google the word "context", but given the exchange so far (especially given that a smiley face emoticon doesn't mean sarcastic humor) I doubt you would be capable of learning from it so I'll just give you a pass.

      John BortonJohn Borton6 tuntia sitten
    • @John Borton Dear John.. I'd advise you go google on 'emoticons, what do they mean and what are they used for'. You might learn something today.

      Jan KlasJan Klas7 tuntia sitten
    • @Jan Klas I see you have no ability to recognize when your 'sarcastic humor' might get muted beyond recognition by thousands of other criticisms.

      John BortonJohn Borton7 tuntia sitten
  • Clowning on physics professors isn't an achievement you get everyday

    Sir ZechsSir Zechs9 tuntia sitten
  • I'm getting a non-stop headache since I've seen this video... ;)

    Marc VerderiMarc Verderi10 tuntia sitten
  • Demonstrating that they're going faster than the wind by itself isn't enough to prove their theory. For example, they could get up to speed and build momentum, then the wind could slow down without necessarily changing direction, which would result in them going faster than the wind and be consistent with their observations. To truly prove this is working they need to verify that the vehicle is continuing to accelerate while going faster than the wind. How do they know the vehicle wasn't decelerating when the streamer was pointing in the opposite direction?

    Dane BeckDane Beck10 tuntia sitten
  • The ripe waterfall lastly rot because mine inadvertently spell under a like creek. guarded, mundane algeria

    Annabelle AnnabelleAnnabelle Annabelle11 tuntia sitten
  • Wacky Races

    A CA C11 tuntia sitten
  • I am not a physicist, but if you add gearbox, doesn't that make the blades spin even faster for the same push force?

    Rodolfo Padilla RuizRodolfo Padilla Ruiz11 tuntia sitten
  • The shaggy position relatively multiply because message happily question in a stiff airplane. lonely, demonic archer

    Katherine MontgomeryKatherine Montgomery11 tuntia sitten
  • I would like to suggest a different explaination. Imagine a different car. In which, large turbine is generating electricity from wind power. This electricity is charging an electric battary. And when the driver descides to move, the energy is activating an electric motor, that pushes the vehicle faster than the wind that charged it. This is trivial. I suggest that the vehicle in the video may not have a battery yet does have a way to store wind power. It does it by keeping the energy in the turbine rotation. The way i consider it goes like this: 1) the vehicle is slowly pushed by the wind. Much of the energy is used to "charge" up the turbine. 2) at some point the vehicle gets to wind speed. However at this point the rotation battary is fully charged and its energy is used to push the vehicle forward. 3) since the wind speed is constant, the extra energy from the turbine rotation would push the vehicle above wind speed. Am I wrong?

    InfoRazorInfoRazor12 tuntia sitten
    • >> Am I wrong? Yes. For our record run in 2010 we had to demonstrate that we could not benefit from stored energy.

      Rick CavallaroRick Cavallaro11 tuntia sitten
  • 8:05 oh god dont give the flat earth guys any ideas

    Matt BrewerMatt Brewer12 tuntia sitten
  • TLD;DR Derek went into the desert and broke wind

    Johnny ThousandJohnny Thousand13 tuntia sitten
  • This broke my brain. But then it healed stronger and better than before!

    Steve BradySteve Brady13 tuntia sitten
    • No pain no gain!

      12ken12ken19 minuuttia sitten
  • Pretty straightforward example of mechanical advantage. The significant mass of the air moving against the vanes of the impeller combined with the gearing of the cart allows for transfer of the kinetic energy of the moving air (wind) to be translated into a low mass vehicle that is easily effected by this acceleration. Once the mass of the vehicle increases, the demand required of the wind to accelerate the vehicle even with mechanical advantage will be too great outside of gale force winds. Will this vehicle accelerate forever? Of course not. It's merely a product of the force of the wind times the mechanical advantage of the machine minus the resistance of the wheels and the drag of the air. Why is this confusing? Ill put $10k on it.

    Senor MisteriosoSenor Misterioso13 tuntia sitten
    • Your explanation sounds more like a wind powered tractor pull when you talk of mechanical advantage. To really understand what is going on, you would get closer to the main idea by comparing it to an ice skater propelling forward by alternately pushing apart then pulling in their legs.

      Adam HuluAdam Hulu13 tuntia sitten
  • Better than mythbusters

    Only 1%Only 1%13 tuntia sitten
  • 8:05 this man just ravaged my round-earth sensibilities

    Ian OlsonIan Olson14 tuntia sitten
  • This video makes me glad that I subscribed last week.

    EJoey2006EJoey200614 tuntia sitten
  • There’s gotta be a motor or something in there

    Shubham MachhiShubham Machhi14 tuntia sitten
  • Sounds almost analogous to a Warp drive (except hear the wind velocity field is being "stretched" and "contracted" rather than spacetime), a wind warp drive! xD

    zaphr89zaphr8915 tuntia sitten
  • Very impressive and congrats to the inventor. However, if we start getting cylindrical earthers, he's getting a knuckle sandwich.

    Mark PoidvinMark Poidvin15 tuntia sitten
    • Grow up.

      Marko BMarko B15 tuntia sitten
  • kiwico toys seems perfect for todays kids! wish i had those toys in my childhood

    El Morto BeatsEl Morto Beats16 tuntia sitten
  • nailed it

    aformaleventaformalevent17 tuntia sitten
  • So could it be possible to do the same type of gear system to a boat propeller and beat the wind speed down wind on a boat

    Neal SullivanNeal Sullivan17 tuntia sitten
  • His cylindrical earth explanation blew my mind. This is genius!

    mmpj twodmmpj twod17 tuntia sitten
  • I’ve always wondered if you could just leave an autonomous plane in a jet stream. Why couldn’t a glider sit there forever maybe as a downlink for something.

    Elliott C (3lliottC)Elliott C (3lliottC)17 tuntia sitten
    • You would at least need an updraft that is greater than or equal to the sink rate. Then you could use a turbine to power whatever systems you like.

      imd12c4adviceimd12c4advice3 tuntia sitten
    • not fair, behind the solar wind from sunset pushed more )))))))

      mmpj twodmmpj twod17 tuntia sitten
  • The null heaven impressively mess up because camera immunochemically spark against a old look. thankful, marvelous voice

    Ryan KhansaryRyan Khansary18 tuntia sitten
  • Brilliant, would probably work with solar winds too.

    Mark TuckerMark Tucker18 tuntia sitten
  • Oh my god this comment section is filled with NERDS

    Infinite GoldInfinite Gold18 tuntia sitten
  • gmod irl

    RiceBoyRiceBoy18 tuntia sitten
  • It happens.

    Yo VinoYo Vino19 tuntia sitten
  • What if this was a impeller instead of a propeller.

    Kylynn BoiKylynn Boi19 tuntia sitten
  • I liked how this video presented the premise and step by step explained how the hypothesis came about and explained it in an understandable way. Not having sailed before, I didn't know exactly how tacking into the wind worked to increase the speed but I understand the concept of propellers and wings. Illustrating the concept step by step is great. I can understand taking a flat surface and making it into a tube, then adding a boat 180 out of sync ( kind of like how a/c voltages 180 degrees out of sync will cancel each other out but when synchronized will double the input ). Its an Ah-ha moment. It flies in the face of physics as we are taught, but every concept we take for granted at one time was considered wrong, against science as we know it. There maybe thousands of theory's in physics that are considered impossible, but sometimes the impossible just means that the method of proving an exact principle hasn't been discovered yet. Virtually everything we use today would have been thought impossible by the best scientists 500 years ago. Go back to the 60's and imagine the writers of Star Trek. They wrote of devices that couldn't possibly exist then but are disposable commodities today. Cell Phones ( communicators ), Medical Instruments, Phasers and Photon torpedo's ( Laser beam weapons ). Our cell phones have more computing power than anything they could have imagined and we think nothing of throwing them away. So to sum it up, the impossible is only that way until someone figures out how to make it possible. If made possible, it may not be practical for real world use, but in the future.....

    sledzillasledzilla20 tuntia sitten
  • Surely the wind speed at the top of the propellor is far greater than the wind speed at the tell tale. Would a tell tale at the centre of the prop still stream back? They surely should have put some velocity sensors and anemometers on at various points to give more concrete evidence. Or at least more tell tales at various points. There are more ways to get a tell tale to stream back too such as stall. I didn't watch this trying to be skeptical or suggest that it is impossible (sailboats go way faster than the wind without defying physics, I assumed at first the propellor could use the backwards flowing apparent wind to drive the craft forward somehow but that doesn't seem to be what is stated) but it would seem fairly easy to give lots of evidence to prove without doubt that it went faster than the wind. Evidence that seems to be lacking. Maybe they can still get this data.

    Wise FoolWise Fool20 tuntia sitten
    • The measurements were already done by NALSA, including windspeed at propeller height. Google: NALSA downwind record

      eyyteeeyytee8 tuntia sitten
  • Saying 'tacking' downwind is triggering me, it's gybing downwind, tacking upwind. This was extremely impressive none the less. I'm still struggling.

    AAEAAE20 tuntia sitten
    • @AAE a tack and a jibe are maneuvers. Tacking however, also refers to the act of taking a zig-zag path to get to a destination - whether that destination is upstream or downstream.

      Rick CavallaroRick Cavallaro13 tuntia sitten
    • @John Borton haha yeah but I sail f18s and we're always going 'upwind', you still reference true wind angle in regards to sailing point (reach, broad reach etc)

      AAEAAE17 tuntia sitten
    • So, if you're downwind VMG is faster than the wind, you now have an actual headwind component to the wind (180 from true). If a sailor was riding on your boat and was unaware of the true wind, they would obviously say you were tacking. Just another weird angle to this mindbender. :)

      John BortonJohn Borton18 tuntia sitten
  • No push back. Very cool!

    Mark Hahn (UrbanRooster)Mark Hahn (UrbanRooster)20 tuntia sitten
    • Plenty of push back. Both in these comments, and from the UCLA physics professor that bet Derek $10,000 that this can't work.

      Rick CavallaroRick Cavallaro13 tuntia sitten
  • you're the next king of random

    Emerson SmithEmerson Smith20 tuntia sitten
  • It's like a solar pannel driving a electric motor

    james Dudleyjames Dudley20 tuntia sitten
    • @Rodolfo Padilla Ruiz I was just saying it's not converting it to electricity but it's storeing the energy in the angular velocity of the wheels while creating drag it is using some of the energy to slow or reverse the fan so that the fan blades has a difference in pressure without slowing the cart down

      james Dudleyjames Dudley3 tuntia sitten
    • Solar panels can do, but not that much unless the surface area is huge and is light enough, like Bertrand Picard's solar plane

      Rodolfo Padilla RuizRodolfo Padilla Ruiz11 tuntia sitten
  • didn't the gearing from the deraileur bike gears have some effect? - if the forces were just from the prop fair enough, but it appeared to be driving the axle via the bike gears and a chain - is this more to do with wind pressure differential than wind speed?

    GHOOGLEMALEGHOOGLEMALE20 tuntia sitten
  • Here’s another thought to help explain this. What if that propeller were made of lead? What if it was only two foot in diameter ? What if the wheels were made of a soft spongy material? What if the body of the car was huge and shaped like a cube? What if the angle of attack of that propeller was 90 degrees, 45 degrees? 10 degrees?

    Stan DavisonStan Davison21 tunti sitten
  • Okay where's Mark Rober? GOnna need him to step in on this. xD

    MegaReddevil91MegaReddevil9121 tunti sitten
  • not fair, behind the solar wind from sunset pushed more )))))))

    Maxim StrakhMaxim Strakh21 tunti sitten
  • 12:17 Something is clearly wrong, as the prop is turning fast, but the car is barely moving. So why is this laid out as a wind speed problem?

    BaDaBingDKBaDaBingDK21 tunti sitten
    • The vehicle has two sets of brakes - a hand brake and a foot brake. But the vehicle weighs 450 lbs without the "pilot". So we like to bring propeller pitch down to zero to do most of the deceleration, and that's pretty effective. Once we're going pretty slow, we use the actual brakes. So this is what we instructed Derek to do - and he did. But it turns out the pitch mechanism has shifted somewhat over the decade since I'd seen the Blackbird. And this had two very unfortunate effects. First the pitch could now go negative rather than bottoming out at zero. Secondly, the pitch was no longer matched between the two blades. This is what caused the awful shaking. So Derek pulled the pitch all the way back, and when he was near a stop, he used the brakes - exactly as we'd suggested. But now he's sitting still with a tailwind and a propeller with negative pitch. Now we have a ratchet that allows the wheels to drive the propeller, but it doesn't allow the propeller to drive the wheels. It will simply let it freewheel. This is there to meet the requirements for the record runs that we cannot use stored energy at any time.

      Rick CavallaroRick Cavallaro13 tuntia sitten
    • Its powered by electric motors, he is just a lying puppet promoting brainwashing content for gullible kids.

      Marko BMarko B15 tuntia sitten
  • Lmao that’s every scientists. They doubt someone’s new idea/discovery just for years later they learn the person they doubted were right. Neil Tyson said himself in his own book “Death by A Blackhole”

    Mr. WordMr. Word21 tunti sitten
    • Neil deGrasse Tyson also signed on as a witness a couple of days ago to the $10,000 bet between Derek and a UCLA physics professor to decide if this is really possible.

      Rick CavallaroRick Cavallaro13 tuntia sitten
  • Worth it.

    flamemaster46flamemaster4621 tunti sitten
  • make sense to me!!!

    John CampbellJohn Campbell21 tunti sitten
  • This is nuts, and ingenious! I think I'm getting the idea. Now if you make the propeller tower a wedge shape, it should be able to catch more tail wind when it's slower than wind speed?

    FatTail BlackSwanFatTail BlackSwan21 tunti sitten
  • i have a question , lets say i have a sail for my skateboard and i mount a fan on it powerd by a battery , im not talking small fan but the kind on stand and i have it blowing into sail , will that make the skatboard go are does it not , think about it , ive been wanting to no this for many manny years

    Andy rimesAndy rimes21 tunti sitten
    • Yes, that will make your skateboard go. But it would be more effective to simply use the fan to push you and leave the sail out of it.

      Rick CavallaroRick Cavallaro13 tuntia sitten
    • Of course it will not go, you cant get free energy like this video is blatantly lying about, they are using electric motors and hidden batteries to brainwash the kids to believe this is real.

      Marko BMarko B15 tuntia sitten
  • First few seconds of video: *suspenseful music "Slow down Derek! Pull back back! Well, I better keep watching, maybe he dies.

    Beretta FanBeretta Fan21 tunti sitten
  • Of course one of the inventors name is Rick. If only the partners parents went with Morty instead of Neil. So close.

    Alhazred01Alhazred0121 tunti sitten
  • It would be interesting to find out the theoretical upper limit of speed that can be achieved .

    János Pisak-LukátsJános Pisak-Lukáts22 tuntia sitten
  • When he said the cylinder analogy, I said out loud "Damn that's a genius." I mean that's exactly the same thought process of deduction Einstein used to figure out most of his theories. Its immensely impressive.

    FluffynatorFluffynator22 tuntia sitten
    • And this is why we aren't making as many new discoveries. It's because people think the answers to the remaining mysteries will be found logically, but in fact they must be found intuitively first, and then use logic to explain, reason, and perfect their theory. Perhaps this is what they mean when we only seem to access a fraction of our brainpower at a time.

      Angelo PiazzaAngelo Piazza17 tuntia sitten
  • I'm a bit sad it doesn't really break the laws of physics, but still pretty cool.

    Dutchlad112Dutchlad11222 tuntia sitten
  • This made me want to buy a hamster, a wooden box on wheels, and a Dyson ring fan to see what happens!

    Tom LeeTom Lee22 tuntia sitten
  • To greatly reduce the wobble, couldn't you use a three blade propeller? I think for wind turbines at least, the wobble can be because of wind shear, that the top blade feels a slightly higher wind speed and thus feels a greater bending moment than the bottom blade when the blades are vertical, and the blades see the same speed when horizontal, causing the wobble. It seems the seesaw oscillation is also exacerbated by the geometry: the fact the blades are opposite each other and connected in the center with a pivot: bending of one can cause counter movement in the other. This used to be accounted for in 2-blade wind turbine designs by having an extra bearing to allow for this motion, but 3-blade turbines are favored nowadays, I think partly because the rotational symmetry/geometry of the three blades greatly reduces this wobbling effect.

    ChrisChris22 tuntia sitten
    • I’m no physicist, but I believe because this was built to achieve faster than wind at a slower wind, the extra surface area wouldn’t be worth the inertia; it would possibly slow it down

      Jareth WormanJareth Worman3 tuntia sitten
  • The way I’ve convinced myself this is true is with a hypotheses: Imagine a vehicle that is going downwind, pushed down by the wind. It also has a fan that is powered by a motor on it which is providing a considerable amount of energy (lesser than the wind itself) to the it (let’s say like 1/3rd the energy from wind). If this vehicle can move faster than the downwind, then the theory & demonstration in the video should be valid.

    Devika K DasDevika K Das23 tuntia sitten
    • It should be valid because if you swap out the motor to the propeller on an angle, in downwind the propeller will act as a fan (as explained in the video)

      Devika K DasDevika K Das23 tuntia sitten
  • Would this work in the opposite direction, headwind? But instead of using the rotor as a fan accelerating air backwards and pushing the vehicle forwards, use it as a windmill which turns the wheels, propelling the vehicle forwards. The faster you go, the stronger the apparent headwind, the more power for the wheels pushing the vehicle forwards. Or would the drag on the windmill always be larger than the amount of work you get from the wind?

    KepeKepe23 tuntia sitten
  • You can’t use the downwind sail analogy. Sails act as wings when you’re reaching or tacking. When you’re running downwind they act as a wall. The angle of the prop blades is what allows you to travel downwind faster than wind. The props act as like a wing. A reaching sailboat can travel faster than the wind. You can vary your speed by changing the angle of attack of the prop.

    Trip BarthelTrip Barthel23 tuntia sitten
    • @Trip Barthel Thanks for clearing up the confusion. For the record, I didn't make the video nor the animations nor was involved in that in any way. I haven't even seen the craft in about a decade. I did design and build the Blackbird many years ago along with Rick.

      John BortonJohn Borton20 minuuttia sitten
    • I totally believe that the tricycle can exceed wind speed. I have to apologize for my confusion on your examples. At the 1:50 mark you show a sailboat running and not exceeding wind speed. This is true. At the 7:50 mark you show how a reaching sailboat can exceed wind speed. This is also true. What allows the tricycle to exceed wind speed is the fact that the prop can push against the wind. This changes the apparent wind so it is able to exceed the true wind speed. So the potential speed equals the true wind speed plus the wind speed from the fan minus the drag. I’d be curious what wind speed the fan was able to generate. Hope this clarifies my thinking. Whole lot of physics going on. The vehicle has to have enough wind to push it forward, thus turning the fan blade in reverse. When you first see the vehicle the assumption is that the prop is being used for propulsion. Once you realize the wheels drive the prop in reverse you can see that it’s possible to exceed wind speed. For a prop to turn you need air movement and there’s no way to get that if you’re moving at wind speed. So the prop would not move once you achieved wind speed. The counterintuitive part is the counter rotation of the prop.

      Trip BarthelTrip BarthelTunti sitten
    • I am confused by your original and broad "You can't use the downwind sail analogy" assertion. Please give me the timestamp for the portion of the animation you claim can't be used. I accepted it as a broad criticism (which would be wrong), but be more specific and I'll take a look. Thanks

      John BortonJohn Borton8 tuntia sitten
    • @Trip Barthel >> The run depicted in the animation is incorrect. I assure you it's not.

      Rick CavallaroRick Cavallaro13 tuntia sitten
    • @John Borton which is exactly what I was saying. The prop is actually set off the wind like a broad reach. The run depicted in the animation is incorrect.

      Trip BarthelTrip Barthel14 tuntia sitten
  • You've been lied to!The Earth is a cylinder!

    Jacob madueñoJacob madueño23 tuntia sitten
  • Has nobody realized how much slower wind is near the ground due to wind being slowed down as a result of friction with the ground? The propeller reaches what 12' above the ground at its highest point? Much higher wind velocity that high off the ground. INVALID TEST PARAMETERS! The wind indicator is mounted what 3' above the ground. LOL....

    Todd SorensonTodd Sorenson23 tuntia sitten
  • I think Formula 1 videos explaining drag are very useful in understanding the whole thing. Moving air molecules have an amount of energy "stored". What the blackbird is doing is moving around collecting energy from them and leaving behind these molecules with less energy than before. If you watch Formula 1 technical videos about drag you'll see representations of this, but opposite. F1 cars "store" energy in the air behind them. The air molecules are at low energies before the car, then the car passes by and drags them, leaving them more energetic than before. The black bird seems to do the reverse. In F1, the car behind actually collects that energy, going faster than if moving through low energy air.

    Guilherme de Moraes AlvarezGuilherme de Moraes Alvarez23 tuntia sitten
  • Fine youtube. I watched it. Are you happy? Will you please stop recommending this now?

    Scott MadayScott Maday23 tuntia sitten
    • No, they gotta brainwash the kids.

      Marko BMarko B15 tuntia sitten
  • It works on boats, so why wouldn't it work on vehicles? Sadly it won't work on flying objects, as there is no fixed point to push it from.

    Josef ŠoltesJosef Šoltes23 tuntia sitten
    • That's why they make wind gradient.

      Rick CavallaroRick Cavallaro13 tuntia sitten
  • Can it keep going or run up with wind then slow down for the next push up to speed 🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯🎯

    Sydney HuntSydney Hunt23 tuntia sitten
  • get redbull involved and make it into a race

    DentistmanDentistmanPäivä sitten
  • Do this but with solar sails

    William SchwarzWilliam SchwarzPäivä sitten
  • You're abbreviated explanation of sailing is a travesty.

    terenfro1975terenfro1975Päivä sitten
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