[ThinAirDesigns]

Spork and I just entered this video in the MythBusters viral video challenge.

http://www.youtube.c...h?v=_fBDcchw5nw

Thought the group might enjoy it since this is one of the forums referenced in the video.

Enjoy

JB

[Junkyard Dog]

You need to shoot a companion video of your cart racing a balloon.

[ThinAirDesigns]

Junkyard Dog, on Nov 16 2008, 11:41 AM, said:

You need to shoot a companion video of your cart racing a balloon.

Why, so everyone can say "The balloon isn't in the same air as the boat", "The device got ahead of the balloon at the start and then the wind switched giving the advantage to the device", "The angle wasn't exactly perfect", "You let the device get up to speed before you let the balloon go". You let the balloon go before you let the device get up to speed", etc etc.

The treadmill in still air IS the most controllable, instrumentable and repeatable way to test and demonstrate that DDWFTTW is possible and breaks no laws of physics. Anything else is just entertainment. If it advances up a level treadmill powered only by the surface/air interface, the test is done and reality has ruled.

Now Junkyard, would one of these racing a balloon be entertaining? Yep ... I'm with you on that one. It just won't answer the critics because they will always have some reason that the wind, altitude and angle isn't perfect.

Best wishes.

JB

[Person]

The use of the treadmill reminds me of that whole 747-trying-to-take-off-from-a-treadmill-runway thing...

edit: which is probably why the narrator mentioned it towards the end. should have waited until the end to hit Post.

[bgulari]

good action!

[ThinAirDesigns]

Person, on Nov 16 2008, 12:01 PM, said:

The use of the treadmill reminds me of that whole 747-trying-to-take-off-from-a-treadmill-runway thing...

While I acknowledge the "thought" similarities between POAT on this experiment, the only true similarities between POAT and DDWFTTW is that like all good brainteasers, they both have proven an ability to fool almost everyone almost all the time, no matter what the education level.

A perfect example: ("from the DDW faster than the wind" thread on this forum)

Quote from member "HWW"

Quote

With all due respect, "when it is going faster than wind speed the wheel (or water prop) is driving the propeller" is non-sense. It violates the laws of physics. You need an extra source of energy to make that happen.

<snip>

You may not concede to my points, why would you, but the laws of physics have the last word on this topic.

btw I am a physicist.

Over and out.

"Over and out indeed" ...The laws of physics *have* spoken and they didn't care a whit about HWW's degree. They spoke using a device that weighs just a third of a pound and can be build by any handiman in any garage.


I'll happily provide a parts list and illustrations for anyone who wishes to build one for themselves. If someone is in the SF Bay area, I'll happily let you use this one and put it on your own treadmill providing you video and post the results.

JB

[mikecb]

My only question is, as the speed of the device approaches true wind speed, apparent wind should move forward, trying to reverse the propellers and slowing the device down again...

Am I totally wrong or what explains why this doesn't seem to happen?

*Edit* I just took a look back into the physics book, and realized that the prop blades can go significantly faster than wind speed, which would more than compensate for any slowing effect

I hope MB picks this up!

[kent_island_sailor]

I call utter BS.
Otherwise the following would work:
You boat (or whatever) can go DDW at windspeed + 3 knots, or TWS+3, for an AWS of 3 with apparent wind from dead ahead.
So....you go out on a flat calm day, get a tow at 3 knots, so now the AWS is 3 knots from dead ahead. You cast off the tow line and cruise all day at 3 knots with NO wind.
:lol:
:lol:

[ThinAirDesigns]

kent_island_sailor, on Nov 16 2008, 01:29 PM, said:

I call utter BS.

As is your right.

I'd be interested in knowing where you think the BS is being executed ... CGI? Optical illusion? Fraudulently modified yellow level?

I ask the above because if you can think of an area we are cheating in the video, *with you* we will devise a test that addresses that issue. We will then make and post you a custom video executing that test and showing the results.

Quote

Otherwise the following would work:
You boat (or whatever) can go DDW at windspeed + 3 knots, or TWS+3, for an AWS of 3 with apparent wind from dead ahead.
So....you go out on a flat calm day, get a tow at 3 knots, so now the AWS is 3 knots from dead ahead. You cast off the tow line and cruise all day at 3 knots with NO wind.

Your scenario is not the same as ours and can never work because of your "calm day" requirement.

Unless there is relative motion between surface (water/land/ice) and air, there is no energy to extract -- no matter how hard you try. The inverse is also true -- as long as there is motion between the two mediums, potential energy exists relative to those two no matter what the vehicle does.

As we've demonstrated, there is no need to break any laws of physics -- all that is needed is a clever mechanism which extracts the above potential energy even if the craft is moving the same speed and direction as one of the mediums.

Let me reiterate -- as with any sailing craft, if the wind stops blowing, this device also stops.

JB

[JimC]

kent_island_sailor, on Nov 16 2008, 09:29 PM, said:

So....you go out on a flat calm day, get a tow at 3 knots, so now the AWS is 3 knots from dead ahead. You cast off the tow line and cruise all day at 3 knots with NO wind.

That would be a perpetual motion machine and can't work... But its not what all these people have built.

[jim lee]

Why not just take one of them mylar helium balloons, tie it to your downwind speeder and let it go down the street. If the balloon drags behind the car, theory proved. If the car drags behind the balloon, theory busted.

-jim lee

[ThinAirDesigns]

jim lee, on Nov 16 2008, 02:22 PM, said:

Why not just take one of them mylar helium balloons, tie it to your downwind speeder and let it go down the street. If the balloon drags behind the car, theory proved. If the car drags behind the balloon, theory busted.

-jim lee

That's *exactly* what Jack Goodman did in his video (with clearly visible streamer rather than balloon). Thousands of posts later, most people still think he cheated -- "not straight downwind", "gust powered", "downhill" etc.

Instead, how about we put it on a treadmill in a controlled environment room and let it go. If it moves forward, theory proved. If it moves back, theory busted. At least in the controlled room it's a lot easier to repeat the test and show we aren't cheating.

JB

[spork]

ThinAirDesigns, on Nov 16 2008, 11:28 PM, said:

Instead, how about we put it on a treadmill in a controlled environment room and let it go. If it moves forward, theory proved. If it moves back, theory busted. At least in the controlled room it's a lot easier to repeat the test and show we aren't cheating.

And yet plenty of people still think we're cheating. I think that will be the one true constant in the universe. We've posted the necessary part numbers and descriptions for people to build one and try it for themselves. JB has even offered to ship his to the detractors. Not a single taker in either case. It must be either easier or more fun to call B.S. from the comfort of your keyboard.

[spankoka]

I don't really understand why people accept that sailing faster than the wind happens all the time on other points of sail, but can't accept the same thing in a sailcraft that is capable of going DDW. This device is just a little more close-winded than some other sailcraft.

[Steam Flyer]

ThinAirDesigns, on Nov 16 2008, 03:22 PM, said:

Person, on Nov 16 2008, 12:01 PM, said:

The use of the treadmill reminds me of that whole 747-trying-to-take-off-from-a-treadmill-runway thing...

While I acknowledge the "thought" similarities between POAT on this experiment, the only true similarities between POAT and DDWFTTW is that like all good brainteasers, they both have proven an ability to fool almost everyone almost all the time, no matter what the education level.

A perfect example: ("from the DDW faster than the wind" thread on this forum)

Quote from member "HWW"

Quote

With all due respect, "when it is going faster than wind speed the wheel (or water prop) is driving the propeller" is non-sense. It violates the laws of physics. You need an extra source of energy to make that happen.

<snip>

You may not concede to my points, why would you, but the laws of physics have the last word on this topic.

btw I am a physicist.

Over and out.

"Over and out indeed" ...The laws of physics *have* spoken and they didn't care a whit about HWW's degree. They spoke using a device that weighs just a third of a pound and can be build by any handiman in any garage.


I'll happily provide a parts list and illustrations for anyone who wishes to build one for themselves. If someone is in the SF Bay area, I'll happily let you use this one and put it on your own treadmill providing you video and post the results.

JB

The problem is not that "the laws of physics" prevent going DDW faster than the wind, using wind as power, but that many people don't understand the difference between "the laws of physics" and intuition.

The "laws of physics" no more prevent a device from going DDW faster than the wind using wind power, than they do prevent a device from going upwind using the wind as power. In fact, it's pretty much the same application.

Ask the same physicist if a sailboat can go upwind. There's your answer.

FB- Doug

[Buford]

>"extracts the above potential energy even if the craft is moving the same speed and direction as one of the mediums."

Extracts energy from the wind when the wind and craft have zero velocity differential?
Sorry mate, that's where it all falls apart.

[spork]

Buford, on Nov 17 2008, 12:57 AM, said:

Extracts energy from the wind when the wind and craft have zero velocity differential?
Sorry mate, that's where it all falls apart.

That's where it falls apart if you don't have a clever way to extract the energy from the ground/wind interface. There are a PILE of ways this can be done however.

[SevenFeathers]

Put the fan on the treadmill too, and then tell me what happens.

7F

[ThinAirDesigns]

SevenFeathers, on Nov 16 2008, 04:06 PM, said:

Put the fan on the treadmill too, and then tell me what happens.

7F

Hi 7F

You'll have to explain your "fan" comment.

If you're thinking that these is a fan offscreen cheating the test, check out that the curtains in the video aren't blowing around in any way. Also, the Mythbusters video is just a composite of a series of video's we have on Youtube. Check out this one where we tilt the treadmill up until the device essentially hovers and then move the camera around to show there are no fans.

http://www.youtube.c...h?v=7xL8gRJ5F6k

Let me know what you think after you watch.

JB

[ThinAirDesigns]

Steam Flyer, on Nov 16 2008, 03:38 PM, said:

... many people don't understand the difference between "the laws of physics" and intuition.

Incredibly well put Doug.

JB

[spork]

ThinAirDesigns, on Nov 17 2008, 01:27 AM, said:

Steam Flyer, on Nov 16 2008, 03:38 PM, said:

... many people don't understand the difference between "the laws of physics" and intuition.

Incredibly well put Doug.

JB

I love it. I may just steal it to use as my signature.

[Mark K]

ThinAirDesigns, on Nov 16 2008, 04:27 PM, said:

Steam Flyer, on Nov 16 2008, 03:38 PM, said:

... many people don't understand the difference between "the laws of physics" and intuition.

..and some don't know the difference between a ribbon tied to the
cart and a balloon that can show actual wind speed.

No doubt, given the history of this place, this thread has wheels.

So, pre-emtively...

http://pic80.picturetrail.com/VOL2001/11181248/19830314/343441781.jpg

[ThinAirDesigns]

Buford, on Nov 16 2008, 03:57 PM, said:

Extracts energy from the wind when the wind and craft have zero velocity differential?
Sorry mate, that's where it all falls apart.

And yet I have a device in my hands which can demonstrate the above on demand -- or even request.

You must stop imagining this device as having the same limitations as a traditional sailing vessel -- our sail is not fixed relative to our hull/chassis.

I understand that when a traditionally sailboat reaches zero wind speed there is no wind across the sail. Remember that when the chassis of this vehicle is a zero wind, it's "sails" are still on a perfectly usable ~45 degree track.

JB

[spork]

Mark,

Can I correctly assume you don't believe this is possible?

[kent_island_sailor]

Some people may not, but I do.

Your device extracts energy from the wind. Relative wind is the ONLY thing that matters. If it can go 2 knots faster than the apparent wind then it matters not if it goes 10 knots in 8 knots of wind, 4 knots in 2 knots wind, or 2 knots in 0 knots wind.
In each case the apparent wind is from 2 knots dead ahead.
BTW, boats cannot sail directly upwind. They do this thing known as "tacking" and the physics behind it have been well known for centuries now.

ThinAirDesigns, on Nov 16 2008, 07:27 PM, said:

Steam Flyer, on Nov 16 2008, 03:38 PM, said:

... many people don't understand the difference between "the laws of physics" and intuition.

Incredibly well put Doug.

JB