Email to Dr. Simanek Regarding DDWFTTW Vehicle Analysis

[jimmcginn]

Dear Dr. Simanek:

I read your excellent explanation of DDWFTTW: https://www.lhup.edu/~dsimanek/museum/DDWFTTW.htm

You missed one thing in my opinion. It involves a poorly understood aspect of aerodynamics. Let me try to explain it to you briefly and then, if you choose, you can examine some of my more comprehensive explanations that were submitted to an online science forum that also involved Rick Cavallaro (Spork). (See links below).

In your article you mentioned differential energy and then made reference to Rick using a wine glass and a ribbon to demonstrate it. We can, I think you will agree, think of differential energy as converting from one form of energy at a lower velocity to one of higher velocity. But, of course, this analogy breaks down in reference to a sailboat tacking across the wind with there being no mechanical means of achieving the differential energy.

What is not well understood is that aerodynamics provides a natural means of achieving differential energy. It's very counterintuitive and so people don't realize that aerodynamics involves an exchange of the energy from wind to that of air pressure. And air pressure has explosive energy that speed limit of which is actually the speed of sound.

If you are so inclined, I hope you won't hesitate to chime in to the conversation.

Regards,

James McGinn / Solving Tornadoes



Introduction of my perspective
http://talkrational.org/index.php/topic ... l#msg68814

Law of conservation of energy:
http://talkrational.org/index.php/topic ... l#msg68970

Aerodynamics:
http://talkrational.org/index.php/topic ... l#msg68992

Angle of attack:
http://talkrational.org/index.php/topic ... l#msg69088

Boats tack to maintain laminar flow
http://talkrational.org/index.php/topic ... l#msg69295

Laminar Flow:
http://talkrational.org/index.php/topic ... l#msg69448

Source of energy #1:
http://talkrational.org/index.php/topic ... l#msg69485

Anecdotal explanations
http://talkrational.org/index.php/topic ... l#msg69689

Leverage:
http://talkrational.org/index.php/topic ... l#msg70001

Reference Requested (and ignored)
http://talkrational.org/index.php/topic ... l#msg70004

Looney notion that energy is frame dependent
http://talkrational.org/index.php/topic ... l#msg70318

Source of energy #2:
http://talkrational.org/index.php/topic ... l#msg70785

Dr. Simanek:
http://talkrational.org/index.php/topic ... l#msg70846



http://talkrational.org/index.php/topic ... l#msg68857

http://talkrational.org/index.php/topic ... l#msg68923

http://talkrational.org/index.php/topic ... l#msg69334

[jimmcginn]

A Long, Strange Trip Downwind Faster Than the Wind
Wired Magazine (See link below)

EDITOR’S NOTE: FEW topics we’ve covered have generated as much debate among readers as Rick Cavallaro and his colleagues proving a wind-powered vehicle can travel downwind faster than the wind. Although we don’t expect this to quell the debate, Cavallaro and John Borton recount their adventure here.

Brainteaser, n — A puzzle that requires mental/cognitive activity to solve and generally includes thinking in unconventional ways with given constraints in mind.

What are the moments when a challenger meets a problem and classic brainteasers are born? Who would have imagined that a plane and a treadmill would end up as inextricably linked as PB&J? Did Monty Hall ever dream the dreams of mathematicians? And if a wind-powered vehicle races a floating balloon and wins are physics texts made obsolete?

Tracing the path of this last riddle leaves a line that passes through moments of competent genius followed by years spent in the stubborn pursuit of absolute silliness. Add a counterintuitive solution and a bunch of name calling amongst academic elites and you have the perfect recipe for an intellectual disaster.

Directly downwind faster than the wind, n — a.k.a. DDWFTTW. An idea that 99 percent of people declare impossible. Ninety-nine percent of the rest can’t figure out how it’s done.

For more follow this link:
https://www.wired.com/2010/08/ddwfttw/

[jimmcginn]

James,

I briefly looked at some of the links. They reminded me why I do not participate in such web forums. They are a quagmire of trivial responses, irrelevant comments, and misinformation. I do not have time to wade through all that muck to find the needles in the haystack that might be useful and insightful.

I do not recall using the term "differential energy" in my web documents. It is not part of the physics vocabulary I'm familiar with. I did mention the ribbon and wine glass demo, and similar devices that move opposite to the force acting on them. I built models of several That's not controversial. Most of the simple machines of the ancients did that. Lever systems, gear systems, pulley systems.

I'm also not sure what you mean by converting "from one form of energy at a lower velocity to one of higher velocity". Probably some engineering jargon with which I'm not familiar.

If there's a web document that addresses your specific concern, I'll consider linking to it. But I'm not inclined to attempt to cover every related detail of this subject.

I saw reference to frame dependent energy in those links. Of course some forms of energy are frame dependent. Kinetic energy of a moving object is zero in a frame moving with it, in which it is at rest. The kinetic energy of an object at rest in one frame, is not zero in a frame moving with respect to it. This gets quite involved when you consider non-inertial reference frames.

-- Donald

Donald E. Simanek, Emeritus Prof. of Physics, Lock Haven University of Pennsylvania
http://www.lhup.edu/~dsimanek/home.htm , Web pages of science, pseudoscience, humor.

[jimmcginn]

Well, Rick is flat out declaring this notion that energy is frame dependent as being the source of the energy that enables speeds in excess of the speed of the wind. He suggested that you supported this supposition. But from what I see here it appears that you would not support Rick's interpretation.

*****************************

Donald:
I'm also not sure what you mean by converting "from one form of energy at a lower velocity to one of higher velocity". Probably some engineering jargon with which I'm not familiar.

Jim:
It's pretty simple to demonstrate the high speed (or potential for high speed) of air pressure. Suppose you have a tube or pipe that is, let's say, 1/4 mile in length. And let's say you cap both ends and evacuate all the air, making a perfect vacuum. if you then open one end of it anything that gets sucked in, let's say a piece of paper, will accelerate to hundreds of miles an hour (possibly) before the column of air slammed into the other end of the pipe. The highest speed attainable is the speed of sound. (Many people don't realize that air molecules in still air are moving upwards of 700 mph.)

Aerodynamics removes the air pressure from one side of an air foil but it leaves the air pressure on the other side, allowing for lift. And lift is an accelerative force that has a speed limit upwards of 700 mph. And so, whereas wind has a speed limit that is the same as the speed of the wind air pressure has a very high speed limit.

I guess what it comes down to is the realization that even though there is something called the law of conservation of energy there is no such thing as a law of conservation of speed. And us humans tend to intuitively assume that energy and speed correlate when in reality they don't or not under all conditions.

I also think there are a lot of misconceptions about the significance of air pressure to aerodynamics. Many people don't realize there is a lot of energy in air.

[jimmcginn]

James,

I did a word search of my DDWFTTW document for "frame" and found no hits. I searched for "differential", and found "differential speed" and "differential pulley", but never "differential energy\". That is not a term I'm familiar with. I try to use physics terms carefully, and if someone finds a goof I correct it. In fact, I have a glossary of commonly misused physics terms and I continually add to it and rewrite it. https://www.lhup.edu/~dsimanek/glossary.htm .

I'd have to see Rick's argument about frame dependence to judge whether it has merit. Sometimes these things are just semantic problems with definitions of terms. There are often alternative ways to analyze things using different language, that turn out to be equivalent. I'm not eager to get involved in such disputes.

Many believers in perpetual motion send me emails with their pet ideas. One annoying misconception they often have is to suppose that one can extract energy from buoyancy, from magnets, or from gravity. They think that pressure and gravity have unlimited energy that can be harvested. And I've lost count of how many cite the refrigerator magnet as a "source of unlimited energy" because it supports its own weight forever, on the metal surface, supposedly using energy in the process. They don't realize that work, the product of force and distance, requires a force moving something through a distance. No motion, no work. And, in a different case, some don't realize that force and distance are both vectors, so a force perpendicular to the motion does no work. On a couple of occasions I've engaged in lengthy discussions with such people, and then regretted it. I avoid that now.

Buoyancy, magnetic fields and gravity are facilitators of energy transfer. They are not magical sources of energy. Energy is not a substance or "stuff" that is "in" things. It is a convenient invented concept to help us describe how things interact with each other. But it is very useful.

Energy of "still" air is the disordered kinetic energy of speedy air molecules. The only way to extract energy from it is to redirect a large portion of those molecules so they are directed in a preferred direction, resulting in ordered kinetic energy. But it takes energy to accomplish that redirection. That's a fundamental principle of thermodynamics. An airplane wing's airfoil redirects air molecules downward, requiring a force to do that, and the Newton's third law reaction force, upward, is responsible for airfoil lift. The process also creates pressure differences that are also helpful. No magic there.

But don't get me into the hoary old question of what causes the lift on an airplane wing. I see so much nonsense on this subject I have often been tempted (but resisted) to write on that subject. Fortunately I don't have to, for physicist John Denker has done it better than I could. https://www.av8n.com/how/ .

The other time I wrote on a subject of "controversial" nature was my document on the cause of ocean tides. I was infuriated by so many textbook and web documents that got it all wrong. My web page "Tidal Misconceptions" provoked a Ph.D. Oceanographer at NOAA to blast me for what he considered a totally wrong web document https://www.lhup.edu/~dsimanek/scenario/tides.htm . He insisted I remove it from the web. I didn't yield to such pressure. Since then I have on several occasions been asked by journal publishers to review papers on that subject. Respectable journals such as the "Journal of Physical Oceanography" and "Ocean Modeling". Those editors seem to consider me an authority on the subject. Far from it, I'm just a physicist who dared to wade into the ocean beyond my depth. But gradually my web page made an impact. Some textbooks and websites have revised their flawed presentations, and doing a lot better. Just last week I submitted a review of a new paper by Eugene I. Butikov of Moscow University, a brilliant 24 page paper that gets it completely right! Of course he'd get it right, for his previous published paper in "The Physical Review" was also excellent. (I reference it in my web document.) But the most satisfying thing was that Butikov cites my website as a good treatment and correction of the many misconceptions about tidal forces. And among the bad examples he cited was one by that NOAA Oceanographer who so angrily objected to my web document. Sweet revenge. Bottom line: The tidal bulges in oceans due to moon and sun are not due to the strength of gravitational forces, but on the differential gravitational forces over material volume. They are not due to centrifugal or centripetal forces. They are not due to rotation. They are not due to "inertia".

But if there were any web debates about my tide document over the past two decades, I didn't look for them, and certainly wouldn't have participated in them if I had. Life is too short to waste.

[jimmcginn]

Donald:
Energy of "still" air is the disordered kinetic energy of speedy air molecules. The only way to extract energy from it is to redirect a large portion of those molecules so they are directed in a preferred direction, resulting in ordered kinetic energy. But it takes energy to accomplish that redirection. That's a fundamental principle of thermodynamics. An airplane wing's airfoil redirects air molecules downward, requiring a force to do that, and the Newton's third law reaction force, upward, is responsible for airfoil lift. The process also creates pressure differences that are also helpful. No magic there.

Jim:
Well, to simplify as much as possible, lift is created when air molecules directly impact that bottom of the wing, transferring energy into the wing. On the top of the wing the air molecules are not impacting directly. They are hitting it with soft, side-glancing impacts. (More precisely, they are hitting the leading edge, causing drag. But they are mostly missing the top of the wing.) Consequently they are not imparting as much downward force. Like you say, this is all consistent with Newton's third law. It's simple mechanics.

What confuses people is that they start with the assumption that the airplane must be creating the energy that is keeping the airplane aloft. They don't realize that the energy that is keeping the plane aloft doesn't need to be created by the airplane because it exists in abundance all around us. It is air pressure. The air foil does not create this force. It doesn't need to. The air foil removes this force from the top of the wing. The net effect of all of this is to direct air downwards, as you indicate. This is both the result of air molecules reflecting off the bottom of the wing and air molecules on the top of the wing missing (or glancing off) the top of the wing as they fall.

Donald:
But don't get me into the hoary old question of what causes the lift on an airplane wing. I see so much nonsense on this subject I have often been tempted (but resisted) to write on that subject.

Jim:
It is a quagmire, but I believe much of the confusion can be avoided by getting people familiar with the counterintuitive fact that there is an abundance of energy surrounding us at all times, air pressure. I honestly believe that if people understand the significance of air pressure first that 90% of the confusion can be avoided.

NOAA has been completely taken over by pseudoscientist with artificially dumbed down explanations targeting the lowest common denominator of the voting public. It is an institution that epitomizes Feynman's claim about cargo cult sciences.

When I get a chance I intend to study your explanation of tides. For the time being the following will be echoing in my mind: "The tidal bulges in oceans due to moon and sun are not due to the strength of gravitational forces, but on the differential gravitational forces over material volume."

There is a plethora of pseudoscience in meteorology:
http://www.thunderbolts.info/wp/forum/phpB ... 71#p115411

[jimmcginn]

James,

Most of what you say seems valid. However, these remarks bother me: "What confuses people is that they start with the assumption that the airplane must be creating the energy that is keeping the airplane aloft" and "I believe much of the confusion can be avoided by getting people familiar with the counterintuitive fact that there is an abundance of energy surrounding us at all times, air pressure".

It suggests that airplanes are tapping pressure energy that is "in" the air. That would, in turn, suggest that the atmosphere in the wake of an airplane has less energy/volume than the air in front of it. The energy to maintain an airplane's forward motion and its lift, is supplied by the airplane's engines, driving the propeller and moving it forward. Turn off those engines and you have a glider, which eventually comes to ground. It cannot maintain lift indefinitely. I still say that air pressure is not a source of energy. Gliders without engines require a high take off point, or a tow from another airplane, and, of course, natural updrafts. The latter do supply external energy. Still air does not.

[jimmcginn]

It suggests that airplanes are tapping pressure energy that is "in" the air.

Yes. And I stand by this assertion. (Explanation below.)

That would, in turn, suggest that the atmosphere in the wake of an airplane has less energy/volume than the air in front of it.

I stated the following in the second post that I linked to above:
"Nevertheless, the atmosphere does not experience a net loss in energy as a result of the aircraft passing through it but actually experiences a net gain in that the amount of energy associated with thrust/drag more than compensates for the loss of energy associated with lift."

The energy to maintain an airplane's forward motion and its lift, is supplied by the airplane's engines, driving the propeller and moving it forward. Turn off those engines and you have a glider, which eventually comes to ground. It cannot maintain lift indefinitely.

I agree that without the airplane's engine it will be a glider, as you suggest. But I still maintain that the actual energy that achieves the lift actually does originate in the atmosphere and not in the engines.

I still say that air pressure is not a source of energy.

I disagree. And I can't envision any other way the wing could achieve lift, especially considering that the bottom of the wing (from leading edge to trailing edge) is parallel (or, mostly parallel) to the direction of air flow below it. (I wonder if there might be an experiment that would distinguish between our respective positions.)

Gliders without engines require a high take off point, or a tow from another airplane, and, of course, natural updrafts. The latter do supply external energy. Still air does not.

I agree that still air cannot produce energy that more than compensates for the lift/drag, which is what I think you mean.

[jimmcginn]

James,

Did you read John Denker's treatise on this subject? https://www.av8n.com/how/ , especially chapter 3. He has the credentials as a pilot, flight instructor AND physicist to get this right. Perhaps you could direct this question to him. Ask him if your assertion is correct: "But I still maintain that the actual energy that achieves the lift actually does originate in the atmosphere and not in the engines."

[jimmcginn]

Did you read John Denker's treatise on this subject? https://www.av8n.com/how/ , especially chapter 3.

I'll take a look. BTW, Cavallaro and his merry band of internet loons have, essentially, conceded the argument. (This does not mean that they have actually conceded the argument. Nor does it mean that they have stopped trying to insult me every chance they get. It just means that they NOW claim to have never claimed that frames of reference power the vehicle and they NOW claim to have always maintained the explanation that I provided. I suppose by the end of the day today they will also claim that they themselves provided the solution.)

BTW, I can't claim credit for the realization that air pressure is the source of the energy of lift in that I recall having been taught that (exactly from whom I can't remember). However, I do take credit for the realization that air pressure has a very high speed potential.

BTW, the reason I am so keen on this notion that air pressure has the potential to produce high speeds is because the same is essential to understanding the origins of the high wind speeds associated with jet streams and tributaries to jet streams, including tornadoes and hurricanes.. I know what you are thinking. I know it seems strange to suggest aerodynamics have a role in the atmosphere because aerodynamics requires a surface and structural resilience in order to achieve some degree of laminar flow. Wind shear along naturally occurring moist/dry boundaries and some of the peculiarities of H2O--specifically the high surface tension of H2O--are instrumental in the realization of this surface and structural resilience, vortices being the most obvious result of this.

He has the credentials as a pilot, flight instructor AND physicist to get this right. Perhaps you could direct this question to him. Ask him if your assertion is correct: "But I still maintain that the actual energy that achieves the lift actually does originate in the atmosphere and not in the engines."

Your tides explanation is very intriguing. I'm trying to shift my perspective of seeing the actual flow of the tides as being the result of shift in volume, itself a result of shifts in gravity (I think), rather than directly the result of gravity. (I hope I'm not completely off base here.)

It's funny how so much of science is so myopically focussed on gravity as the primary cause of everything that moves. Meteorology's superficially simplistic notion that convection (buoyancy) powers storms is another example of this collective lunacy.

Regards,

James McGinn / Solving Tornadoes

[jimmcginn]

Hi John,

Thank you for your excellent website.

Is there any chance you would like to weigh-in on this conversation between myself and Dr. Simanek?

The point of contention here involves whether or not the potential for high speed of air pressure explains the aerodynamics of faster than wind vehicles.