Going downwind faster than the wind

[RogueSpidor]

If you're not interested, and don't want to understand the math, models, and analogies - so be it.

I'm going to decide this time only that you're not trying to insult me. I'll remove myself from this topic for the time being. Meanwhile, go on with your math that I obviously have no hope of understanding, discuss your models and analogies that are obviously way over my head. And when you collect whatever prize you'd get for making cartoon physics a reality, I'll publicly say you were right. Until then, please carry on without me.

[spork]

Yup.  Jack Goodman has done exactly that.
Do we have a a video of that test?

Sadly we don't.  But I'm almost certain Jack Goodman still has the vehicle.  He's somewhat less hard headed than me, so he's not all that keen on participating in forums where he's called all sorts of names that probably won't make it through the filters.  But this forum does seem so be somewhat more civil than some we've been on.  Perhaps he could be persuaded to join the forum, and maybe take video of his cart on the treadmill.

I can tell you this much... on many forums he'd be told that the treadmill video is just as fake as the outdoor video.

I do know that Jack is a fan of the Mythbusters, and is also eager to see them do a segment on this.  Shall I invite him to join the forum?

The math and examples would point to it working, but my intuition says it can't work and I must be missing something.

That's the mark of a good brain-teaser.  I collect the brain-teasers I really like, and most of them are extremely counterintuitive - but can be demonstrated.  Just by way of a VERY simple example...

Q: how much bigger is the rim than the basketball - 10%, 20%, 30%... 50%???

A: 100%

Hard to believe, but you can go measure it.

[Wolfyhound]

Please keep it civil.  If you can't dispute the accuracy, at least show something that disproves the theory.
To me it looks impossible, because it looks like a over-unity idea(which I understand it is not, because it utilizes wind).  I'm not going to pretend that I understand all the vectors and such.  Sailboats were just something we tried not to run over when we were commercial fishing.
It sounds like a cool candidate for a "viral video" or something like that.  I'm not that far from Tampa, and I'm tempted to make a run out there to see that thing.  I could video.. lol.  To me the video looks like it's just rolling on a slight downhill slope.
I'd only wonder if the guys could make it entertaining enough for tv, and be able to explain it on the tv without going so complex that viewers will be turned off.  

[RoofingGuy]

It's kind of like saying you can sit in a boat with a sail, point a fan at it, and make the boat move forward.

Don't bother trying it. That only works in cartoons.

I knew I'd seen it somewhere other than Bugs Bunny.

<a href="http://www.youtube.com/v/0CrXvOKPymk" target="_blank">http://www.youtube.com/v/0CrXvOKPymk</a>

[spork]

I'm going to decide this time only that you're not trying to insult me.

I am in no way trying to insult you.

...when you collect whatever prize you'd get for making cartoon physics a reality...

You're quite clearly trying to insult me - but that's OK.  I can take it.

I'd only wonder if the guys could make it entertaining enough for tv, and be able to explain it on the tv without going so complex that viewers will be turned off.

I think it's a bit like the "plane on a treadmill" in that respect.  I'm sure they'll never explain it in a way that satisfies everyone, but if they show a cart doing something that many people just KNOW is impossible, it seems plenty entertaining to me.

[spork]

I knew I'd seen it somewhere other than Bugs Bunny.

Nice find RoofingGuy - and proof positive that my memory is completely useless.  I've seen that video as well.

[ThinAirDesigns]

So, in three short pages, the power of this myth has already been demonstrated.  Exactly like POAT, it's counterintuitive in a way that instantly brings out very strong opinions -- most of which turn out to be wrong.

A perfect example follows:

It's kind of like saying you can sit in a boat with a sail, point a fan at it, and make the boat move forward.

Don't bother trying it. That only works in cartoons.

Fast, sure and right on point ... "Don't bother trying it".

Well, as it turns out -- with a fan, wheels and a simple paper towel the 'sailboat powered by an onboard fan' has not only been tried, but done and video documented.  Any doubters can similarly rig a fan to their hearts content.

No different with a device traveling directly downwind, faster than the wind, powered only by the wind -- people immediately associate it with perpetual motion, over unity or like RogueSpidor, the "cartoons".  Almost everyone (myself included at first) scoffs at the idea that at the moment it's moving the same speed as the wind and a streamer on it's chassis is hanging limp, there is *any* energy available for extraction -- they forget that it's the *relationship* between the two mediums that is being exploited.  That relative motion between the air and the ground remains no matter what speed the vehicle moves.

I've found there are two examples that are key to understanding a DWFTTW device:

1:  It's done on frozen lakes the world over every winter.  The *downwind component* of an iceboat so easily, so dramatically and so regularly exceeds that of the wind itself as to render the argument "it defies the laws of physics" absolutly useless to anyone willing to educate themselves.   Also, top of the line racing sailboats now regularly tack downwind rather than flying a spinnaker and can also achieve the above.   

2:  Any old sailboat can, while drifting down the Mississippi river on a calm day, outrun it's "power source" (the river).  Drop a balloon in the water at the river dock and anyone with any sailing experience can catch it, pass it and leave it in the boat's wake.  Similarly, release a neutral buoyancy balloon in the moving air and the DWFTTW will catch it pass it and leave it in it's wake.

Both of the above examples leave lie to the argument "it defies the laws of physics".  Once you leave that argument behind, then it only becomes "OK, *how* can it be done".

JB

[Cybermortis]

Sadly we don't.  But I'm almost certain Jack Goodman still has the vehicle.  He's somewhat less hard headed than me, so he's not all that keen on participating in forums where he's called all sorts of names that probably won't make it through the filters.  But this forum does seem so be somewhat more civil than some we've been on.  Perhaps he could be persuaded to join the forum, and maybe take video of his cart on the treadmill.

I can tell you this much... on many forums he'd be told that the treadmill video is just as fake as the outdoor video.

Its ironic that so many people will happily accept that a cell phone will pop popcorn, or that someone has a perpetual-motion machine because of clips on Utube...Yet not accept footage of the moon landings or anything that challenges what they perceive to be the 'truth' *sighs*

Anyway.

The problem here is as Mythbusters explained it on the viral hour - don't trust what you see on Utube because it is very easy to show what-ever you like with special effects and camera tricks.

While I'm not for one second accusing anyone of doing this in this case, you would have to admit that it wouldn't be all that hard to concoct ways to 'show' this device working when it really isn't - two of us here have both come up with ways to duplicate the footage and I that (as far as I know) neither of us has spent any time thinking about it. (I mean, maybe I'm just the suspicious type but I can think of ways the video linked above could have been faked).

To be clear (again) I'm not saying either video is fake, just that I can see ways to do it without much effort.

You could do another video, but the same problem turns up - it could be faked, since it is safe to assume anyone doing so isn't going to film anything that lets on what is really happening.

The only way around this, and the only truly viable video evidence, would be to get a third party to inspect the device closely both before and during a real test and to be allowed to film when and what they like and post the results.

[ThinAirDesigns]

The only way around this, and the only truly viable video evidence, would be to get a third party to inspect the device closely both before and during a real test and to be allowed to film when and what they like and post the results.

To be fair Cyber, the video with the fan and paper towel is so easy to replicate that anyone interested can do it at home -- small clip on fan, kids toy car and a sheet of notebook paper.

Admittedly, a DWFTTW device is harder to replicate, though the "third party" you describe above is only very slightly different from what the task of Jamie and Adam is each and every episode -- they research, they document, they "post".

JB

[RoofingGuy]

With all due respect, though, Cyber, there is one clear difference.

With the other usual crop of YouTube $%^&.. er, "stuff", the intelligent know instantly that it's faked -- they know the exact reason(s) why it isn't even slightly possible.  They don't even have to look for, or explain, the fakery.  Run a T.V off a AAA battery?  Ya, maybe for half a second if you neglect losses in the power conversion and the maximum current a single cell can source -- after that, it's out of juice.  Cook popcorn with a cellphone?  Well, let's see... how much power (joules/second) does the cell phone put out in all directions vs. how many joules does the water need input to it to flash into steam and pop the corn?

Sure, anyone could fake a cart that is solely wind-powered outrunning the wind.  It could have a small motor.  It could be towed.  It could be a slight grade.  It could have parts digitally removed.  Etc, etc, etc...

But, there's a difference.

Like the sailboat tacking into still air and beating the current, the cart just instinctively feels all wrong.  It "shouldn't" work.

But the math behind it says it will work with the right blade pitch and the right gearing, and there's no actual Physics reason for it not to work.

Like I alluded to, I could see no true reason for it not to work, despite how wrong it felt, but for the longest time I didn't eve try to give it much consideration.  However what I could do during that time was show the glaring mistakes in the "reasons" it couldn't work that others were giving, even though I thought I must be missing something and it shouldn't work.

Then one day the light bulb went off and I realized that there was no reason for it not to work, and there were no laws being broken.  After that, getting a grasp on how it worked wasn't that difficult.

If I wasn't that busy with all the chaos around here I would build a mini version and throw it on the treadmill with a level and a windsock and video what happens.  I'm confident it would shoot to the forward end against the belt's motion.

So, even if the video were faked (which I don't think it was), there's never been a valid reason why it "must" have been faked, other than the multitude of "it can't work because I say so".

Whether the video is fake or not is somewhat immaterial to the actual concept.  Without a valid reason/proof for it not to work, it is a testable concept for the 'Busters, and testing it would be more educational, and more entertaining, than demonstrating the lack of chemical energy in a AAA battery.

[spork]

The only way around this, and the only truly viable video evidence, would be to get a third party to inspect the device closely both before and during a real test and to be allowed to film when and what they like and post the results.

BINGO!!!!  That's where the Mythbusters come in.  People can argue that the Mythbusters "did it wrong", but no one with half a brain will argue that they faked any results.  That's precisely why I want *them* to show it's possible.

By the way.  I *know* it would be easy to fake that video.  I have little doubt most of us on this forum could fake it easily.  However, I know it needn't be faked, because unlike popping popcorn with a cell phone, it can be done.  It *is* done every single day in so many ways.  I demonstrate it several times a week on my kiteboard.  But the real ticket is to have the Mythbusters replicate the feat in any mode they like, and show it in the correct perspective (as I feel they did with POAT).


I know I keep coming back to this.  But I think it all comes down to whether or not you believe an ice boat (or even a competition sailboat) can tack downwind faster than the wind.  If you believe this, we're nearly there.  If you don't, please say so.  It's easy enough to provide evidence that I think would satisfy most people on this forum.

Aside from that approach, it really would be curious to understand why it shouldn't work to put sails that retract and deploy on the spokes beneath the hub.  If you haven't tried it with your bicycle yet, you really should run out to the garage, grab a spoke below the hub, and give it a push.  I think you might be surprised at what happens.

I'm reasonably confident I can convince most anyone on this forum that approaches it with an open mind, that this can work.  And I think I can do it without any math or vectors to complicate matters.  If you're a doubter, give me a chance.

Or better yet, just get the producers to give the slightest indication of interest, and I'll build one.

If I'm wrong I'll beat everyone to the punch in admitting so - and there will be great rejoicing.


Welcome to the forum BubbleBoy (er ThinAirDesigns).  It always helps to have a 2nd or 3rd clear mind and perspective on these things.  The only danger is that we'll convince everyone too soon, and then it won't seem like much of a myth.  In that case we'll invite some of the detractors from the kitesurfing forum, the hang gliding forum, the R/C heli forum, the Discovery channel forum, the yachting forum...  I say "P.O.A.T. or bust".

If memory serves (and it rarely does), I think you were one of the great detractors initially.  I seem to recall RoofingGuy being a pretty tough sell too.

[RogueSpidor]

You're quite clearly trying to insult me - but that's OK.  I can take it.

I do believe the initial stone was cast by you, but your belief system seems flexible.

Regarding the video: without seeing it actually done instead of a video that specifically mentions your login name on it... that is to say, unless I see it done knowing that no electromagnets or other trickery were involved, I'm skeptical.

It does appear to be doing exactly what you describe. You're 3/4 of the way to your cartoon physics prize.

Understand, please, that I'm a paranormal debunker in my spare time; if I can think of a way it could be faked in the picture or video, I can't be positive that it isn't. And I can think of at least 3 ways that video could have been faked. I can't take the video at face value. I'm not saying that it is faked, only that I can't trust it because I wasn't there when the film was made. It does, however, indicate that it's more possible than I'd initially thought. The other 25% to the prize is demonstrating it before the prize officials (no, that's not me; so far as I know, there's no prize for that).
Since you're not likely to be near me, or able to demonstrate it to me yourself, it would be unfair to make such a demand in order to concede the point to you. So, I'll make some efforts to try this on my own, with a small fan, boat, water, and sail when I have time to clap it all together. If it works when I do it, I'll concede this point. In the meantime, I'll change my opinion from "impossible" to "I don't know, but I should find out before I comment further on it."

If it does work, then I'll further concede that the original post may be possible as well, but as has been said earlier, that video could also have been faked.*

I'll go one step further; the inclusion of a flywheel in the mechanical linkage could help between gusts of wind. Has anyone attempted anything with that kind of design?

*I'm not putting it on par with the "diamonds from a microwave, charcoal, and peanut butter" videos, but I can't be 100% sure it's bona fide.

[spork]

I do believe the initial stone was cast by you, but your belief system seems flexible.

I don't know what this "first stone" was, my belief system is completely consistent (although I try to remain open minded), and I really don't want to have a pissing match with you or anyone else.

Regarding the video: without seeing it actually done instead of a video that specifically mentions your login name on it...

You might have noticed that my login name was mentioned at the end by the guy that posted the video - he was simply thanking me for the discussion that led him to test it for himself.

...that is to say, unless I see it done knowing that no electromagnets or other trickery were involved, I'm skeptical.

Skepticism is good.  Implying that the mere mention of my login name means that trickery must have been used it not.

You're 3/4 of the way to your cartoon physics prize.

Your insistence on describing this as cartoon physics is designed to make me look foolish.  In the end it will certainly make one of us look foolish.  Time will tell.

Understand, please, that I'm a paranormal debunker in my spare time

I'll keep that in mind.  And if I post anything relating to the paranormal I'll look for you to chime in.

if I can think of a way it could be faked in the picture or video, I can't be positive that it isn't. And I can think of at least 3 ways that video could have been faked.

Yes - it could be faked.  We've all said so.  I'll say it again.  But there's no need to fake it.  That would be like me faking a car rolling downhill.  Why would I need to fake something that physics alone will do for me?

The other 25% to the prize is demonstrating it before the prize officials (no, that's not me; so far as I know, there's no prize for that).

Please keep in mind that I haven't applied for, nor do I intend to accept, the cartoon physics prize should it be awarded.

If it works when I do it, I'll concede this point. In the meantime, I'll change my opinion from "impossible" to "I don't know, but I should find out before I comment further on it."

That's a big step - and all I could ask for.  I think you'll find that if you bend the sides of the sail backwards it will work even better.  It will never work as well as simply pointing the fan in the other direction.  The reason thrust reversers are built the way they are is simply because it's a big job to turn the engine itself around.

If it does work, then I'll further concede that the original post may be possible as well, but as has been said earlier, that video could also have been faked.*

The two are independent.  They can both work.  I realize not everyone will believe it.  There's no doubt the video *could* be faked.  But I'm extremely pleased that you're willing to consider considering it : )

I'll go one step further; the inclusion of a flywheel in the mechanical linkage could help between gusts of wind. Has anyone attempted anything with that kind of design?

The prop does act as a flywheel itself.  But since the object is to prove it can work steady-state, this is more of a liability than anything.  It just makes it possible for people to point to the flywheel and say "that's what makes it work".

Did you try the yo-yo problem?  It's very interesting.  Or pushing your bike by the spoke beneath the hub? 

I have a prediction... you're going to be one of the biggest proponents once you convince yourself.  It wouldn't be the first time.

[RoofingGuy]

Regarding the video: without seeing it actually done instead of a video that specifically mentions your login name on it... that is to say, unless I see it done knowing that no electromagnets or other trickery were involved, I'm skeptical.

Fair enough.  I can offer some background on the fan/sailboat video, though...

It started as one of many arguments over at Disco.  Most were taking the "standard" answer of it not working and being a cartoon joke.  A few (including spork) pointed out that if the sail ends up deflecting the air backwards that it will be the same principle as a jet engine with thrust reversing, although lacking in efficiency. (You can even note in the video that with just the attached fan, or with the "wind" there was far more propulsion than what the onboard fan could provide by blowing into the sail.)

KSquared took it upon himself to test what would happen with a simple setup.  As I recall, it wasn't a matter of "it works and I'll prove it", but "I'd like to see what would really happen if I try -- who's right here?"  In other words, a true experiment, as opposed to a demonstration.

Other than magnitude and efficiency, I see no Physics reason why there would need to be fakery.  A jet engine makes lots of forward thrust by ejecting high-speed air backwards.  If you re-direct that air forwards, by vanes attached to the engine, then the net force switches to being rearward and you get thrust reversal, even though the engine itself is pushing the air backwards at the onset, and is "pushing against itself" through the vanes.

The sailboat/fan combination should provide some level of forwards thrust as long as some of the air is ultimately deflected rearwards.  Yes, at first it sounds silly because it IS a stock cartoon joke, but there's no Physics reason for it to not work as advertised.

Skepticism is good.  Following blindly and unquestioningly is bad.  I encourage others to test the fan/sailboat themselves.  It doesn't really matter what setup you choose.  You could use a balloon for the thrust into whatever sail you choose, or a small DC fan, or an RC prop engine.  If there is a level of rearward deflection of the air by the sail, there should be forward propulsion -- it's action/reaction.

I can see how the closing note thanking spork and others for the discussion that led to the experiment can add to skepticism... it can be read as "here spork, I made this video to show that you're right."  But this really is a DIY setup with very little planning needed that anyone can do.

But, of course, even if each MBFC member were to test the fan/sailboat themselves, that is still far removed from validating the downwind cart video.  It is, however, helpful in noting that perceived wisdom sometimes needs additional thought.

I really do wish I had the time to build a small downwind cart of my own, but since I've already expressed my "it works" view, I could be seen to resorting to trickery as well.  The natural skepticism (which is good) doesn't help motivate me to make the time to build one.

[spork]

I've changed my mind.  I will proudly accept the cartoon physics award if I'm fortunate enough to win it.  It will look great on my "I love me" wall.