Merged DDWFTTW in a “Real” Wind

[ThinAirDesigns]

I spite of all the effort Ynot put into multiple versions of the wind tunnel and the respect I give him for that, those videos are truly the last of all the evidence I would try to submit if I were doing such.

The insult here is being “truly the last of all the evidence I would try to submit” effectively saying my efforts and demonstrations have been a complete waste of time and worthless.

Ynot, let me clarify my "last of all evidence I would try to submit" comment:

If I were attempting to convince a panel of scientists as to DDWFTTW, or if I were attempting to submit evidence for record purposes, I would not submit your wind tunnel videos. I explained exactly why (because I couldn't myself verify that they actually demonstrated DDWFTTW). Your turntable video is as solid as can be and I would happily submit that.

The one thing I do think is funny here is you keep making this silly claim that it was all just "for you". ********. It was clear then and it's clear from your insulted tone here that it wasn't just for you. If it were just for you, A: you wouldn't have need post it and B: you wouldn't be freaked like you are about it now.

JB

Edited by LashL: 

Edited to properly mask profanity. Please see Rule 10.

 

[jadebox]

I thought of another "thought experiment" that shows that the balloon must travel at wind speed.

We measure wind speed in reference to a fixed point on the ground. So, let's replace the surface of the earth with a large treadmill (sound familiar?).

Release the balloon and watch it float with the wind. Now, crank up the treadmill and start moving the ground until it's moving the same speed and direction as the wind, now ... for you standing on the "ground" ... the air is still, it isn't moving.

What's the balloon doing?

According to humber, it'll be drifting towards you because it never reached wind speed. But, it'll actually be standing still - as would be expected for a balloon in still air.

-- Roger

 

[ThinAirDesigns]

A) this makes me very happy

Since some like to pretend there is only "Spork & Co", I would like to clearly separate myself from the above statement. It will not surprise anyone who knows me that I generally don't wish for unfortunate events to befall even those I don't like.

This position will not surprise Spork -- we disagree often.

JB

 

[mender]

ETA: I see Humber posted a link to something that is actually cogent and relevant on this. Congratulations Humber!

Notice he didn't dare to offer an explanation ...

 

[windgrins]

Interesting Observation (At least to me.)

I was thinking about Spork's car with balloon video and the video of "balloons in a van" which had helium balloons from the floor and air balloons from the ceiling. The following thoughts dawned on me:

It occurred to me that air balloons hanging from the ceiling with mass m and string length x act as a pendulum (aerodynamically draggy as we most know by now). A helium balloon with bouyancy m and string length x acts as an inverted pendulum with negative mass!

Assuming the two are close in aerodynamic size, the superposition of the behavior of the two replicate the behavior of the NB balloon in Spork's car and balloon video. This is one area where superposition actually works!

2nd thought:

With a deflection calibration for acceleration of a lighter than air helium balloon, a video camera, an initial starting direction, and a clock, one could build a "poor mans inertial Nav system for the car". Amazing what one could do with a balloon

This was interesting, at least to me!

Diagram for illustration and not to scale as described above.

Windgrins

 

[humber]

NB balloon nit-pick:

A normal, small balloon filled with air won't be NB. The air contained is slightly compressed (denser) than surrounding medium. Also, the membrane itself is clearly denser than surrounding air, hence, a mix of He and air would be required. Even then, as the balloon gets larger, its shape becomes less spherical because of density changes in altitude. A very large balloon will take on an inverted pear shape. Said shape may develop lift in a wind before it gets to windspeed, slightly skewing the data.

That's not a "nitpick" quarky, but some of the physical phenomenon I previously mentioned. There is no single "NB" balloon, but many mass/volume permutations. A balloon with a high surface to mass ratio will accelerate faster. A Mylar balloon, of the "flat face" type, will probably accelerate quite well, but have a lower top speed because of the bluff front ( assuming it stays upright). It won't, but strikes a compromise by flying at an angle.

In another experiment, unrelated to balloons, but perhaps to the turntable:
I've toyed with making a floating magnet toy for years. Its a rascal. I thought I could replace the gyroscope with a cantilevered, counter-weighted, low c.o.g. toy; to prevent the inevitable flipping over. But no. The gyroscope behaves as a lighter version of the counter weight because of its angular momentum.
More on this if anyone wants. I know it isn't very clear, much less how it relates to the turntable experiment.

OK, I am curious.
When a teenager, I made a magnetic levitation toy. In fact it was a small shoe polish container. Optical feedback controlled the position, by varying the current in the supporting electromagnet. It is relatively stable in other ways, because the magnetic field passes through the metal skin of the container, so deviation tends to right itself. Perhaps that can be done with fixed magnets, and the proximity effect of the object.

 

[humber]

Dear god man you are persistent in your willful ignorance. In the first response to the Airport walkway suggestion it was made clear that the speed of the walkway was only 2 mph and the model needs a ws of 4 mph.

And that makes you obtuse. Where in the transform can you find a wind speed restriction? If there were one, then TAD went out of their way with the self-start tests, to show that there isn't one. It will not start because the TM is not a valid transform, but the speed limit is a convenient way of not showing that. Perhaps from its failure, you can learn how it really works. If the prop oscillates, that opens the question as to why it does that, and allows force to be calculated. If it is spun up by some means and then put on the belt, that tells even more.
The reason is for the refusal is that TAD can't explain things like that.
And I suppose the fan of the test was carefully measured to ensure it met the necessary limits, was it?

You ignored this and stated that the bb operated at lower speeds, even from a standing start. This totally ignores the ws when the bb was at a standing start, which I'm not looking up, but I am quite sure was well over 4 mph.
If you really can't understand this distinction then there is likely no hope.

No, don't you dare look that up. Never look at the data.
It won't start even in a 10mph wind, and why not?
Your argument is circular and relates two situations by one apparent common failure, and worse. When there is ice on the road, drivers slow, and the accident rate falls, but that does not mean putting ice on the road is a good way of preventing accidents, nor that the ice is the cause of the reduction.

 

[humber]

If I were attempting to convince a panel of scientists as to DDWFTTW,

The first stumbling block would be opportunity.

or if I were attempting to submit evidence for record purposes, I would not submit your wind tunnel videos. I explained exactly why (because I couldn't myself verify that they actually demonstrated DDWFTTW). Your turntable video is as solid as can be and I would happily submit that.

Both would be rejected out of hand. One question that could not be met by "this pushes than and goes faster 'n' all" would see you shown the door.

 

[humber]

I thought of another "thought experiment" that shows that the balloon must travel at wind speed.

We measure wind speed in reference to a fixed point on the ground. So, let's replace the surface of the earth with a large treadmill (sound familiar?).

The atmosphere moves with the Earth's rotation. Wind is local motion.
That can be seen on Jupiter, where transient wind patterns move with the rotation of the planet. Your model means that the wind in one town would be the same as one 1000 miles away.

Release the balloon and watch it float with the wind. Now, crank up the treadmill and start moving the ground until it's moving the same speed and direction as the wind, now ... for you standing on the "ground" ... the air is still, it isn't moving.
What's the balloon doing?

Wondering why someone wearing a tin hat while on a treadmill.
That's a truly marvelous experiment. Change the direction of the belt or stop it, and the balloon knows instantaneously what it must do.

 

[humber]

Since some like to pretend there is only "Spork & Co", I would like to clearly separate myself from the above statement. It will not surprise anyone who knows me that I generally don't wish for unfortunate events to befall even those I don't like.

This position will not surprise Spork -- we disagree often.

JB

Well, JB, fair enough, but that may be connected to why Spork finds so many attack him.

 

[humber]

Notice he didn't dare to offer an explanation ...

How about you pick up that baton and have a go, and see how you get on against my reply?

( BTW: When Spork posts a puzzle, so do you)

 

[jduffy77]

Mmmm....that wager won't happen ( and I think it's against the rules to make them), but you would lose if the videos exist or not, because for $100K, one could construct something either legitimate of false, that would take your money. In other words, the only limit for me in taking the money, is your capacity to see how it works. You already accept Spork's simple yarn, so you will certainly accept mine.

I too believe that the wager will not happen because I do not believe that either you or RP truly believe what you write. As for being against a rule that would certainly surprise me since the whole point of this site was to try to inject reality into kooks and cranks claims using an offer of money.

I am not sure what you are talking about when you mention me accepting your yarns. I would have nothing to do with it. The escrow agent would move the money into either my account or your account as dictated by the agreement. I do not have to understand how it works.

 

[quarky]

That's not a "nitpick" quarky, but some of the physical phenomenon I previously mentioned. There is no single "NB" balloon, but many mass/volume permutations. A balloon with a high surface to mass ratio will accelerate faster. A Mylar balloon, of the "flat face" type, will probably accelerate quite well, but have a lower top speed because of the bluff front ( assuming it stays upright). It won't, but strikes a compromise by flying at an angle.



OK, I am curious.
When a teenager, I made a magnetic levitation toy. In fact it was a small shoe polish container. Optical feedback controlled the position, by varying the current in the supporting electromagnet. It is relatively stable in other ways, because the magnetic field passes through the metal skin of the container, so deviation tends to right itself. Perhaps that can be done with fixed magnets, and the proximity effect of the object.

Is this a de-rail? Oh, well...shouldn't matter in this thread.

The mag-lev toy I was chasing (postponed for now) was non-electric.
There are several on the market now that use electro magnets.
Others don't, but are contained by a structure they can bump into as needed...like an up-town version of dough-nut magnets on a pencil. They sort-of float.

With a flywheel (gyroscope) I believe I could pull it off, but only as long as it spun at a certain speed. Hence, input of power needed.

The floating magnet used to be considered a no-go, as per the law(s).
Not sure anymore. Lots like ddwfttw, in a way.

The 3rd thing that intrigues me, of similar fringie science, is the vacuum balloon. There's a cool engineering problem.

 

[quarky]

Think to come of it, floating the magnet is a lot like keeping a neutrally buoyant balloon in place.
Its not stable.
Easy to do with people blowing streams of air at it, or better yet, a machine.
But there is no stability in balance, oddly enough. Its a fluke.

 

[windgrins]

Vacuum Balloon

The 3rd thing that intrigues me, of similar fringie science, is the vacuum balloon. There's a cool engineering problem.

Was this mentioned earlier? I think the only issue whatsoever with a vacuum balloon is materials science. It's pretty hard to build a sphere to withstand 15PSI that would be light enough to actually float. However there is a patent applied for just exactly this-pat application number 11/517915.

Since the density of air at sea level is about 1.2 kg/m3 (1.2 g/L) the vacuum balloon would have as its buoyancy this (displaced volume weight - the mass of the envelope). so a cubic meter vacuum balloon has to weigh less than a kilogram to be very useful. That's a tough problem.

WindGrins

 

[humber]

Think to come of it, floating the magnet is a lot like keeping a neutrally buoyant balloon in place.
Its not stable.
Easy to do with people blowing streams of air at it, or better yet, a machine.
But there is no stability in balance, oddly enough. Its a fluke.

It will be unstable for sure.

I mean permanent magnets. Some stability can be done with permanent magnets by shaping the paths the induced field takes or perhaps saturating part of it.

 

[windgrins]

Humber Half Right-Better than before!

That's not a "nitpick" quarky, but some of the physical phenomenon I previously mentioned. There is no single "NB" balloon, but many mass/volume permutations.

Humber's correct up to here.

From his responses to me earlier, It's pretty clear he doesn't know what a Neutral Buoyancy Balloon is from his earlier statement about them:

1. "So, rises because the denser air replaces it."

2. "The balloon is less dense, so has less gravitational force for the same volume.
That's how a ship floats. "

He doesn't seem to understand that an NB Balloon doesn't rise-That's why we call it Neutrally Buoyant!

A balloon with a high surface to mass ratio will accelerate faster. A Mylar balloon, of the "flat face" type, will probably accelerate quite well, but have a lower top speed because of the bluff front ( assuming it stays upright). It won't, but strikes a compromise by flying at an angle.

It's gotten to the point where its just no longer fun to point out why this is obvious nonsense and has been demonstrated by both physics and physical experiment as such earlier in this blog.

Windgrins

 

[quarky]

Was this mentioned earlier? I think the only issue whatsoever with a vacuum balloon is materials science. It's pretty hard to build a sphere to withstand 15PSI that would be light enough to actually float. However there is a patent applied for just exactly this-pat application number 11/517915.

Since the density of air at sea level is about 1.2 kg/m3 (1.2 g/L) the vacuum balloon would have as its buoyancy this (displaced volume weight - the mass of the envelope). so a cubic meter vacuum balloon has to weigh less than a kilogram to be very useful. That's a tough problem.

WindGrins

I may have brought it up earlier. i think I even started a thread on it some time back. Memory fades. Lethargy prevents search.

Yes, I've crunched lots of numbers. Scaling up the radius gets gobs more volume, yet demands better structure. geodesics; carbon fiber members; state of the art membranes...I think it is do-able. Yet, it would be even sillier than the cart, as per cost/purpose ratios go.

A side curio item that is do-able, imho, is a frame and a membrane filled with helium; then evacuated just enough to show the membrane sucking inward.
A nice illusion...yet one that wouldn't last long. helium has a way of wiggling through most membranes over time, even with a pressurized air surrounding it.

The optimist in me feels that such abstract, yet fundamental quests, will reveal practical side effects...like the quest to land on Mars.
A vacuum balloon would be cheaper than that, but more than the BB cart, I suspect.

btw, Windgrins...it wouldn't need to support 15 psi. This is where it gets funny. Bigger sphere; less vacuum? How about 5 psi?

 

[humber]

I too believe that the wager will not happen because I do not believe that either you or RP truly believe what you write. As for being against a rule that would certainly surprise me since the whole point of this site was to try to inject reality into kooks and cranks claims using an offer of money.

If it was not here, is was at RDF. The wager gambit is never taken up.
However, yours is particularly foolish, as you are offering 100:1 with a

minimum of $1k. The carts work as is, but for that money there are many who could repeat what I have already said is possible, or build a cart that will certainly fool you. The aim is to say "if your cart does work, why don't you take the wager".

I am not sure what you are talking about when you mention me accepting your yarns. I would have nothing to do with it. The escrow agent would move the money into either my account or your account as dictated by the agreement. I do not have to understand how it works.

I mean that if you have already accepted Spork's fairy tale about the cart on the belt, then you will be fish in a barrel for anyone else.
And you have never had any experience with escrow, perhaps state gambling laws.

 

[jadebox]

That's a truly marvelous experiment. Change the direction of the belt or stop it, and the balloon knows instantaneously what it must do.

Yes, in the universe you've created, the balloon's movement would depend on the movement of the belt. But, in the real universe, it doesn't.

-- Roger