...as a claim that storms as damaging as Sandy occur in this area with only a 1-in-700-year probability. As the article says, however, this was an unusual storm in a number of ways, and a more conventional storm causing at least as much damage is more probable than a repeat of Sandy.
It might well have been cheaper to have some London firefighters trained and ready to call in if needed for something like this.
That's already part of the policy and that is what happened. It may have allowed operations to resume earlier than otherwise.
Paying overtime for a crew of firefighters might have been cheaper than the downtime.
If you want this argument to be plausible, you should go quantitative. My guess is that the people setting the policies spent more time thinking about this than you did, used quantitative analysis, and are competent.
Sorry, your rambling - that is supposed to be a question I presume - is a tad incoherrent....
Wether or not a PL takes over is dependant on things that usually have nothing to do with the PL itself. Once a PL is sufficient enough.... ok, scratch that...
And what a crock -- that Koreans would crash a plane because of a respect of hierarchy. This is just racist. Sorry, I take that back. It's just stupid.
If it was just Gladwell making things up as usual, I wouldn't take it very seriously, but the effect showed up in a valid statistical study: crashes are somewhat more likely when the Captain rather than the First Officer is at the controls, even after controlling for factors like the Captain tending to take control in difficult situations. The effect is by no means limited to Korea, or Asia in general. It is least evident in Australia (though the data set there is rather sparse).
No one is suggesting that anyone is making a conscious decision in these cases, but cultural conditioning has more, mostly subconscious, influence on behavior, especially during stress, than most rational people would prefer to believe. In addition, I guess that there would be similar related factors, such as the personalities and mood of the individuals, that might dominate this effect in any given situation.
In this case, the article referenced in the OP has only vague and incomplete information about the ranks, seniority, and experience of the flight crew, and it makes no attempt to consider other reasons for the lack of talk (such as no-one noticing the developing problem, which would be a puzzle, but a different one), so the article looks like idle speculation.
Gnash is the perfect example - you have the opportunity to fix it, but the source code is such a pain in the ass to get around that nobody does it. Pick any large project with long standing bugs...
I don't consider Gnash even close to being a large project. OpenOffice.org, Linux Kernel, Ubuntu, KDE, Firefox, Second life.. Sure.
Gnash is not being presented as a large project, it is presented as an open-source project that is not, in any practical sense, 'fix it yourself' (admittedly, the referenced post would be clearer if it had a paragraph break between the Gnash example and the claim concerning large projects.)
Wasn't the issue in Firefox that people couldn't reproduce it (I couldn't)? And there was no reasonable documentation presented to explain exactly where the issue was.
Far from refuting the claim that 'fix it yourself' is largely a myth, this observation is actually supporting evidence for the proposition that 'fix it yourself' can be impractically difficult, even if you have the source.
Combine these observations with this about Ubuntu's 'bug 1', and it is clear that while your post looks superficially like a rational argument, it is actually just a collection of non-sequiturs.
Add to that the decision to prosecute without an independently verified audit trail, and the magistrates' decision to allow such prosecutions to proceed.
The article appears to be a slightly pretentious way of saying that Netflix does reliability testing on its live systems. They can get away with this only because it is not critically important for Netflix to be highly robust: the downside of failure is merely a degree of temporary irritation. Don't try this in the financial markets or life-support systems.
What we're really seeing here is the impatience of the Now Generation. What? You have to wait -thirty minutes- for something to be produced?? OMG!
Not only that, but the author is simply creating trinkets. He has no worthwhile use for this device, and he is too self-absorbed to realize that this renders his opinions largely uninteresting.
There should be a corollary to Clarke's law about how quickly people develop feelings of entitlement with regard to technology, even though (or because) they don't understand what it takes to make it happen.
Most software written in COBOl tends to be a tangled mess that can't be easily split up and decoubled.
More modern languages have done little, if anything, to reduce a programmer's ability to create a confused mess. Goto may be gone, but inheritance has tremendous power for cryptic obfuscation, and I have seen way too many cases where a programmer has used this capability to the hilt. Perhaps most frustrating are the cases where a rewrite has ended up no better than the original.
Nothing about censorship says it has to be done under a threat
...and so it is not necessarily anything to be concerned about. Free speech is infringed when a person is either prevented from communicating or is coerced into not communicating by the threat of retaliation for doing so. In the case in question, no-one is having his free speech infringed, and the suggestion of an entirely hypothetical and utterly implausible circumstance (one in which Martin's Blog's comments section is the only channel of communication for these trolls) does nothing to alter the facts of the case.
Wasn't aware there was any controversy about this. I always thought it was believed to be a meteor or comet. Of course, I underestimated the power of human imagination.
I think there was a tiny window of doubt because no large remnant could be found, but 'icy comet fragment' and 'explosion at altitude' were always plausible explanations for that, even before the Chelyabinsk meteor convincingly demonstrated the latter.
I can't imagine how this technique could go beyond a graph of word associations to an understanding of their meaning. The graph seems to be entirely self-referential.
Humans do it the other way - if they are asked about the relatedness of words, they infer it from the meanings they attribute to the words.
...explain to the client that the actions of their new developer have put them in an actionable (take you to court) position
I would avoid any hint of an adversarial position between you and the company unless one already exists. Instead, see if you can get a reference that includes a statement that you developed the code in question.
I would emphasize the fact that the plagiarizer is publicly claiming copyright of a work that the company owns. If this is client-side Javascript, it is unavoidably public (unless on a private network), but otherwise, the plagiarizer has also apparently made public the private property of the company.
One of the common themes in cart discussions is that different people require wildly different sorts of explanations or analogies for it to "click".
I don't think you can truly understand what's going on without a mathematical model (using high-school math and physics) or at least a numerical example. I think it is clear from the varied explanations in this thread that many of the people who claim they understand it, don't (the contradictory explanations make this pretty clear.)
In most cases throwing a wall of numbers their face is... unhelpful.
There are always going to be some people who will say they can't (or won't) follow the math, but they know you are wrong. They probably don't believe in relativity, either.
Also note that the explanation which did work for you demonstrated that the cart can work, but in many ways (and for many people), it's a completely worthless non-explanation of how it works.
The solution to that is not less math, but more - a model of the propeller, showing the forces generated. It's still at high-school level, I think, if you assume only the lift and drag curves of an airfoil as a function of airspeed, and I hope to attempt it.
Since you are a calculations-person, check out the almost magical "how" of wind-energy-collection going on in the following calculation:
The wind is going left at 10 m/s, cart is going 20m/s in the same direction. From the point of view of the cart, the air is going 10 m/s to the right. The kinetic energy of 1 kg of air at 10 m/s is 50 joules. (ke=1/2*mv^2). The cart spends energy to run the prop, accelerating the air faster to the right. The air leaves the prop at 12 m/s rightwards In the frame of the cart). The kinetic energy of the air has increased to 72 joules. Simple enough... the cart spends energy running the prop accelerating the air, and naturally energy is transferred from the cart into the air.
There's the paradox - the cart appears to be losing energy to the air...
But now look at it from the ground frame. The air is a wind going 10 m/s to the left. 1 kg of air has a kinetic energy of 50 joules. The cart prop is pushing that air rightwards, the resulting in 8 m/s in the ground frame. The kinetic energy of this air, in the ground frame, is now 32 joules. 50 joules - 32 joules = 18 joules of energy vanishing from the air. Where does the energy go? The only place it could go is into the cart, and a careful analysis shows the cart's kinetic energy increasing by the power applied to the prop PLUS the energy lost from the air. The power applied to the prop is then subtracted back out by the drag at the wheels. The net result is the wind energy being teleported into the cart. From the ground frame the air energy went *into* the cart (increasing the cart's kinetic energy). This clearly shows the energy being extracted from the wind. But remember what the car's point of view was.... the cart was spending energy running the prop to pump energy OUT of the cart and INTO the air. The cart saw energy flowing in the opposite direction! Doh!
That's it! - both the core of the paradox and a hint of the solution. If you intuitively think of the power as some sort of fixed amount of fluid that is flowing through the device, you may intuitively estimate it in different frames of reference for different parts of the cart, which will never come out right. You must stay within one frame of reference, and compare one to the other strictly through Galilean transformations. As you point out, in one framework, the air gains energy, while in the other it loses it. While paradoxical (at least in the light of my high-school physics, which glossed over this aspect of the formulae), this is neither a contradiction nor a violation of the conservation of energy - all that physics requires is that when you consider all the sources and sinks within a single framework, energy is co
Unless it's not grade data but raw data. Everyone is ASSUMING it's final calculated scores.
From the description of how the data were obtained, you can see that it is the data from which the Exam Results web page delivers the final calculated scores.
A good explanation should go to the heart of the paradoxes, which are these: how can you power the motion of a cart by extracting power from its motion? How does taking power from the wheels lead to power being extracted from the wind? Your first attempt at an explanation looked like just a collection of factual inaccuracies, non-sequiturs and assertions to be taken on faith (like all the others here and in many other places), but I have to admit that within this version, you have the best simple explanation that I have seen. All you needed to write was this:
Consider a cart going 30 feet per second in a 20 foot per second MPH wind. The car is going 10 feet per second faster than the wind, so there's 10 feet per second of air going through the prop. Lets put one pound of drag on the wheels. Again, power = force * velocity. Power = 1 pound * 30 feet per second. The drag at the wheels generates 30 foot-pounds per second of power. We feed that 30 foot-pounds per second of power into the prop. Power = force * distance. The distance is 10 feet per second of air through the prop, so we have 30 foot-pounds per second = force * 10 feet per second. Solving that we get Force = 3 pounds. The prop can covert that power into up to 3 pounds of thrust. Even if the prop is only 50% efficient, it's still generating 1.5 pounds of thrust. The cart is going faster than the wind, and accelerating.
You follow this by comparing it to a lever, which makes your explanation look bogus because we all know that you can't construct a system of levers that moves itself. A few numbers are more convincing than any amount of hand-waving 'explanations' like "would have to spin crazy fast..." This is a case where more (sentences) is less (of a plausible explanation).
This explanation could be strengthened with an estimate of achievable power-to-thrust ratios for the propeller, but with airfoils being capable of lift/drag ratios of 50, I don't doubt that it would be satisfactory. A calculation of the power balance would also help, but that has already been done: while the papers you link to discuss the conditions that need to be satisfied without showing that they can be, this one does.
There is also a much better video than any I have seen of the Blackbird, from a different team with a different machine. Putting streamers outside of the stream-tube that goes through the rotor, and with one high enough to demonstrate that wind shear is not a factor, is convincing. In contrast, the Blackbird team attempted to demonstrate the relative wind in a truck that alternately fell behind and caught up with the cart. They only had a couple of shots of the wind vane (none during most of the FTW part of the run), and you cannot tell if these were during the periods when the cart was catching up with the truck or if the wind was gusting (the BUFC have another video here which shows the cart passing a flag that shows the true wind direction. It would be nice to have a sequence of airspeed readings from pitots mounted at the streamer positions, together with the corresponding ground speeds.)
This is moot, but I have no idea where you got the idea that airplanes need millions of horsepower. WWII fighters were in the 2000 - 5000 hp range, while the F1 racing planes are using hundreds rather than thousands of horsepower. A high-performance sailplane dissipates about 2hp at its most efficient speed, around 60 mph.
The reduction of efficiency of propellers at low airspeed is a general effect, and I believe it is mostly due to recirculation of the airflow at the tips.
Note that you have completely eliminated the wind from the system.
No, the wind is still blowing. What I have eliminated is the windmill. Recall that this is the explanation in which the rotation of the wheels provide power to the windmill, which acts as a propeller, using that power to generate thrust. This variation introduces an alternative way to use that power to generate thrust.
The wind and the propeller are blowing at each other, pushing against each other.
This looks like the bogus "the exhaust pushes against the air" explanation of how a rocket works, but that's kind of irrelevant, as this vehicle is travelling faster than the wind. This means the relative wind is in the same direction that the propeller accelerates the airflow, so the idea of "pushing against each other" would not apply here, even if it were a valid explanation of thrust generation.
The power-driven prop is going to to be very inefficient and it will struggle trying to generate any significant thrust to the rear in a 100 MPH airflow already heading to the rear
The propellers of airplanes efficiently generate thrust in a 100 mph airflow, and well above. It is just a matter of having the right diameter, blade-count, pitch, twist and angular velocity.
Propellers are extremely efficient at generating a thrust against still air.
Check the "Thrust at Constant Power vs. Airspeed" chart here, where the thrust initially increases with airspeed This is presented as a typical case, not a special or corner one.
Any non conservative field can have energy extracted from it, so this is clearly possible -as long as there is something-in this case the water-that is moving at a different velocity than the wind
True, and demonstrated by sailboats for millenia, but this is incomplete as a proof that the Blackbird works as described. It's like saying that we know nuclear fusion releases energy, so that must be what is happening in Rossi's E-Cat.
I like it, but it doesn't work as an explanation for the Blackbird, which has the windmill fixed to the rest of device, so they both always experience the same relative wind. Whenever your device anchors its power-extraction device to the ground, it is arguably more analogous to a sailboat on a reach than to the Blackbird.
Furthermore, many of the explanations in this thread (I think it's a majority, but I haven't counted) have the windmill acting as a propeller driven by the wheels, rather than as a turbine extracting power from the wind. This explanation is favored by those who wonder what happens when the device is travelling at the wind speed. Your device inspired me to come up with a variant, which I have described elsewhere in this thread.
Slashdot Mirror
...as a claim that storms as damaging as Sandy occur in this area with only a 1-in-700-year probability. As the article says, however, this was an unusual storm in a number of ways, and a more conventional storm causing at least as much damage is more probable than a repeat of Sandy.
It might well have been cheaper to have some London firefighters trained and ready to call in if needed for something like this.
That's already part of the policy and that is what happened. It may have allowed operations to resume earlier than otherwise.
Paying overtime for a crew of firefighters might have been cheaper than the downtime.
If you want this argument to be plausible, you should go quantitative. My guess is that the people setting the policies spent more time thinking about this than you did,
used quantitative analysis, and are competent.
The sooner, the better. You need an agile bug response process.
I don't see what a bunch of lawyers can contribute to that.
Bringing legal action got the issue on Slashdot, so it turned out to be an effective way to raise awareness that Secunia's position is bogus.
What's the V8 Javascript engine written in?
'nuff said.
Code it in C or get out of the way and let a real programmer finish the project.
What does the machine actually execute?
'nuff said.
Sorry, your rambling - that is supposed to be a question I presume - is a tad incoherrent....
Wether or not a PL takes over is dependant on things that usually have nothing to do with the PL itself. Once a PL is sufficient enough .... ok, scratch that...
And what a crock -- that Koreans would crash a plane because of a respect of hierarchy. This is just racist. Sorry, I take that back. It's just stupid.
If it was just Gladwell making things up as usual, I wouldn't take it very seriously, but the effect showed up in a valid statistical study: crashes are somewhat more likely when the Captain rather than the First Officer is at the controls, even after controlling for factors like the Captain tending to take control in difficult situations. The effect is by no means limited to Korea, or Asia in general. It is least evident in Australia (though the data set there is rather sparse).
No one is suggesting that anyone is making a conscious decision in these cases, but cultural conditioning has more, mostly subconscious, influence on behavior, especially during stress, than most rational people would prefer to believe. In addition, I guess that there would be similar related factors, such as the personalities and mood of the individuals, that might dominate this effect in any given situation.
In this case, the article referenced in the OP has only vague and incomplete information about the ranks, seniority, and experience of the flight crew, and it makes no attempt to consider other reasons for the lack of talk (such as no-one noticing the developing problem, which would be a puzzle, but a different one), so the article looks like idle speculation.
I don't consider Gnash even close to being a large project. OpenOffice.org, Linux Kernel, Ubuntu, KDE, Firefox, Second life.. Sure.
Gnash is not being presented as a large project, it is presented as an open-source project that is not, in any practical sense, 'fix it yourself' (admittedly, the referenced post would be clearer if it had a paragraph break between the Gnash example and the claim concerning large projects.)
Wasn't the issue in Firefox that people couldn't reproduce it (I couldn't)? And there was no reasonable documentation presented to explain exactly where the issue was.
Far from refuting the claim that 'fix it yourself' is largely a myth, this observation is actually supporting evidence for the proposition that 'fix it yourself' can be impractically difficult, even if you have the source.
Combine these observations with this about Ubuntu's 'bug 1', and it is clear that while your post looks superficially like a rational argument, it is actually just a collection of non-sequiturs.
Not having the audit trail should be the crime.
Add to that the decision to prosecute without an independently verified audit trail, and the magistrates' decision to allow such prosecutions to proceed.
The article appears to be a slightly pretentious way of saying that Netflix does reliability testing on its live systems. They can get away with this only because it is not critically important for Netflix to be highly robust: the downside of failure is merely a degree of temporary irritation. Don't try this in the financial markets or life-support systems.
What we're really seeing here is the impatience of the Now Generation. What? You have to wait -thirty minutes- for something to be produced?? OMG!
Not only that, but the author is simply creating trinkets. He has no worthwhile use for this device, and he is too self-absorbed to realize that this renders his opinions largely uninteresting.
There should be a corollary to Clarke's law about how quickly people develop feelings of entitlement with regard to technology, even though (or because) they don't understand what it takes to make it happen.
Most software written in COBOl tends to be a tangled mess that can't be easily split up and decoubled.
More modern languages have done little, if anything, to reduce a programmer's ability to create a confused mess. Goto may be gone, but inheritance has tremendous power for cryptic obfuscation, and I have seen way too many cases where a programmer has used this capability to the hilt. Perhaps most frustrating are the cases where a rewrite has ended up no better than the original.
Nothing about censorship says it has to be done under a threat
...and so it is not necessarily anything to be concerned about. Free speech is infringed when a person is either prevented from communicating or is coerced into not communicating by the threat of retaliation for doing so. In the case in question, no-one is having his free speech infringed, and the suggestion of an entirely hypothetical and utterly implausible circumstance (one in which Martin's Blog's comments section is the only channel of communication for these trolls) does nothing to alter the facts of the case.
Some had thought it was a comet, but here's the thing: people would have distinctly seen the "tail" of even a small comet as it approached the Earth,
Comet's tails tend to fade away as the surface volatiles get used up.
Wasn't aware there was any controversy about this. I always thought it was believed to be a meteor or comet. Of course, I underestimated the power of human imagination.
I think there was a tiny window of doubt because no large remnant could be found, but 'icy comet fragment' and 'explosion at altitude' were always plausible explanations for that, even before the Chelyabinsk meteor convincingly demonstrated the latter.
I can't imagine how this technique could go beyond a graph of word associations to an understanding of their meaning. The graph seems to be entirely self-referential.
Humans do it the other way - if they are asked about the relatedness of words, they infer it from the meanings they attribute to the words.
...someone is going to read what you wrote and think that one or both of us said it's a turbine.
Don't worry - it's only us here.
...explain to the client that the actions of their new developer have put them in an actionable (take you to court) position
I would avoid any hint of an adversarial position between you and the company unless one already exists. Instead, see if you can get a reference that includes a statement that you developed the code in question.
I would emphasize the fact that the plagiarizer is publicly claiming copyright of a work that the company owns. If this is client-side Javascript, it is unavoidably public (unless on a private network), but otherwise, the plagiarizer has also apparently made public the private property of the company.
One of the common themes in cart discussions is that different people require wildly different sorts of explanations or analogies for it to "click".
I don't think you can truly understand what's going on without a mathematical model (using high-school math and physics) or at least a numerical example. I think it is clear from the varied explanations in this thread that many of the people who claim they understand it, don't (the contradictory explanations make this pretty clear.)
In most cases throwing a wall of numbers their face is... unhelpful.
There are always going to be some people who will say they can't (or won't) follow the math, but they know you are wrong. They probably don't believe in relativity, either.
Also note that the explanation which did work for you demonstrated that the cart can work, but in many ways (and for many people), it's a completely worthless non-explanation of how it works.
The solution to that is not less math, but more - a model of the propeller, showing the forces generated. It's still at high-school level, I think, if you assume only the lift and drag curves of an airfoil as a function of airspeed, and I hope to attempt it.
Since you are a calculations-person, check out the almost magical "how" of wind-energy-collection going on in the following calculation:
The wind is going left at 10 m/s, cart is going 20m/s in the same direction. From the point of view of the cart, the air is going 10 m/s to the right. The kinetic energy of 1 kg of air at 10 m/s is 50 joules. (ke=1/2*mv^2). The cart spends energy to run the prop, accelerating the air faster to the right. The air leaves the prop at 12 m/s rightwards In the frame of the cart). The kinetic energy of the air has increased to 72 joules. Simple enough... the cart spends energy running the prop accelerating the air, and naturally energy is transferred from the cart into the air.
There's the paradox - the cart appears to be losing energy to the air...
But now look at it from the ground frame. The air is a wind going 10 m/s to the left. 1 kg of air has a kinetic energy of 50 joules. The cart prop is pushing that air rightwards, the resulting in 8 m/s in the ground frame. The kinetic energy of this air, in the ground frame, is now 32 joules. 50 joules - 32 joules = 18 joules of energy vanishing from the air. Where does the energy go? The only place it could go is into the cart, and a careful analysis shows the cart's kinetic energy increasing by the power applied to the prop PLUS the energy lost from the air. The power applied to the prop is then subtracted back out by the drag at the wheels. The net result is the wind energy being teleported into the cart. From the ground frame the air energy went *into* the cart (increasing the cart's kinetic energy). This clearly shows the energy being extracted from the wind. But remember what the car's point of view was.... the cart was spending energy running the prop to pump energy OUT of the cart and INTO the air. The cart saw energy flowing in the opposite direction! Doh!
That's it! - both the core of the paradox and a hint of the solution. If you intuitively think of the power as some sort of fixed amount of fluid that is flowing through the device, you may intuitively estimate it in different frames of reference for different parts of the cart, which will never come out right. You must stay within one frame of reference, and compare one to the other strictly through Galilean transformations. As you point out, in one framework, the air gains energy, while in the other it loses it. While paradoxical (at least in the light of my high-school physics, which glossed over this aspect of the formulae), this is neither a contradiction nor a violation of the conservation of energy - all that physics requires is that when you consider all the sources and sinks within a single framework, energy is co
Unless it's not grade data but raw data. Everyone is ASSUMING it's final calculated scores.
From the description of how the data were obtained, you can see that it is the data from which the Exam Results web page delivers the final calculated scores.
A good explanation should go to the heart of the paradoxes, which are these: how can you power the motion of a cart by extracting power from its motion? How does taking power from the wheels lead to power being extracted from the wind? Your first attempt at an explanation looked like just a collection of factual inaccuracies, non-sequiturs and assertions to be taken on faith (like all the others here and in many other places), but I have to admit that within this version, you have the best simple explanation that I have seen. All you needed to write was this:
Consider a cart going 30 feet per second in a 20 foot per second MPH wind. The car is going 10 feet per second faster than the wind, so there's 10 feet per second of air going through the prop. Lets put one pound of drag on the wheels. Again, power = force * velocity. Power = 1 pound * 30 feet per second. The drag at the wheels generates 30 foot-pounds per second of power. We feed that 30 foot-pounds per second of power into the prop. Power = force * distance. The distance is 10 feet per second of air through the prop, so we have 30 foot-pounds per second = force * 10 feet per second. Solving that we get Force = 3 pounds. The prop can covert that power into up to 3 pounds of thrust. Even if the prop is only 50% efficient, it's still generating 1.5 pounds of thrust. The cart is going faster than the wind, and accelerating.
You follow this by comparing it to a lever, which makes your explanation look bogus because we all know that you can't construct a system of levers that moves itself. A few numbers are more convincing than any amount of hand-waving 'explanations' like "would have to spin crazy fast..." This is a case where more (sentences) is less (of a plausible explanation).
This explanation could be strengthened with an estimate of achievable power-to-thrust ratios for the propeller, but with airfoils being capable of lift/drag ratios of 50, I don't doubt that it would be satisfactory. A calculation of the power balance would also help, but that has already been done: while the papers you link to discuss the conditions that need to be satisfied without showing that they can be, this one does.
There is also a much better video than any I have seen of the Blackbird, from a different team with a different machine. Putting streamers outside of the stream-tube that goes through the rotor, and with one high enough to demonstrate that wind shear is not a factor, is convincing. In contrast, the Blackbird team attempted to demonstrate the relative wind in a truck that alternately fell behind and caught up with the cart. They only had a couple of shots of the wind vane (none during most of the FTW part of the run), and you cannot tell if these were during the periods when the cart was catching up with the truck or if the wind was gusting (the BUFC have another video here which shows the cart passing a flag that shows the true wind direction. It would be nice to have a sequence of airspeed readings from pitots mounted at the streamer positions, together with the corresponding ground speeds.)
This is moot, but I have no idea where you got the idea that airplanes need millions of horsepower. WWII fighters were in the 2000 - 5000 hp range, while the F1 racing planes are using hundreds rather than thousands of horsepower. A high-performance sailplane dissipates about 2hp at its most efficient speed, around 60 mph.
The reduction of efficiency of propellers at low airspeed is a general effect, and I believe it is mostly due to recirculation of the airflow at the tips.
Note that you have completely eliminated the wind from the system.
No, the wind is still blowing. What I have eliminated is the windmill. Recall that this is the explanation in which the rotation of the wheels provide power to the windmill, which acts as a propeller, using that power to generate thrust. This variation introduces an alternative way to use that power to generate thrust.
The wind and the propeller are blowing at each other, pushing against each other.
This looks like the bogus "the exhaust pushes against the air" explanation of how a rocket works, but that's kind of irrelevant, as this vehicle is travelling faster than the wind. This means the relative wind is in the same direction that the propeller accelerates the airflow, so the idea of "pushing against each other" would not apply here, even if it were a valid explanation of thrust generation.
The power-driven prop is going to to be very inefficient and it will struggle trying to generate any significant thrust to the rear in a 100 MPH airflow already heading to the rear
The propellers of airplanes efficiently generate thrust in a 100 mph airflow, and well above. It is just a matter of having the right diameter, blade-count, pitch, twist and angular velocity.
Propellers are extremely efficient at generating a thrust against still air.
Check the "Thrust at Constant Power vs. Airspeed" chart here, where the thrust initially increases with airspeed This is presented as a typical case, not a special or corner one.
Any non conservative field can have energy extracted from it, so this is clearly possible -as long as there is something-in this case the water-that is moving at a different velocity than the wind
True, and demonstrated by sailboats for millenia, but this is incomplete as a proof that the Blackbird works as described. It's like saying that we know nuclear fusion releases energy, so that must be what is happening in Rossi's E-Cat.
I like it, but it doesn't work as an explanation for the Blackbird, which has the windmill fixed to the rest of device, so they both always experience the same relative wind. Whenever your device anchors its power-extraction device to the ground, it is arguably more analogous to a sailboat on a reach than to the Blackbird.
Furthermore, many of the explanations in this thread (I think it's a majority, but I haven't counted) have the windmill acting as a propeller driven by the wheels, rather than as a turbine extracting power from the wind. This explanation is favored by those who wonder what happens when the device is travelling at the wind speed. Your device inspired me to come up with a variant, which I have described elsewhere in this thread.