Kylie Irving: The Earth is Flat

Gator2222

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"Many people have argued that John Hanson, and not George Washington, was the first President of the United States, but this is not quite true. Under the Articles of Confederation, the predecessor to the US Constitution, the United States had no executive branch. The President of Congress was a ceremonial position within the Confederation Congress. Although the office required Hanson to deal with correspondence and sign official documents, it wasn't the sort of work that any President of the United States under the Constitution would have done."

https://www.constitutionfacts.com/us-articles-of-confederation/john-hanson-story/

That's what makes the debate around this subject so fun. Washington wrote Hanson a letter congratulating him on being the first president of the US. Hansen was given the title of president of the US. Hansen created the presidential seal that is still in use today. He was appointed president after the colonies declared independence from Britain.

I think those who oppose the idea of Hanson being the first president are motivated by tradition as much as anything else. Personally, I don't care which is considered the first.

However, in my opinion, if history and science teachers used these types of debates in class it would make the subjects much more appealing and enjoyable.
 

Gator2222

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I think it's just easier for people to visualize the concept. If you take it beyond that you have to really start getting into the weeds of how an airfoil actually works. I think the equal time model is more for explaining Bernoulli than it is for explaining lift. Bernoulli and lift are not exactly the same thing.

That's exactly the explanation the flight instructors gave. LOL. I've never tried to teach these things to people so I will defer to them and assume it's the best way.
 

bradgator2

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Yes I've been flying professionally for 24 years.

When you drink out of a straw, aren't you sucking the coke into your mouth? Well an engineer might point out that actually what you are doing is creating a low pressure area above the drink and allowing the high pressure atmosphere around the drink to force the fluid up the straw and into your mouth. Does this make the original statement wrong? Not really, it just expounds upon it and goes into more detail.

Equal transit time IMO is simply an incorrect inference. The air going over the top of the wing is certainly moving faster and creating lower pressure (and resulting in lift) than the air going under the wing. I don't think that two adjacent molecules splitting up at the front of a wing and rejoining at the trailing edge of the wing was the thrust of how Bernoulli principle was explained to me way back when. Bernoulli certainly applies to airflow since air is a fluid. Where geeks go crazy is thinking that the shape of the wing is the only thing creating differential pressure. Heck, an isosceles triangle has a flat bottom and a longer path on top but it certainly wouldn't create enough lift to fly by running it quickly through the atmosphere. The real story is that the air going over the wing not only travels faster than the air going underneath, but in fact much faster than would be calculated simply by measuring the distance from the leading edge to the trailing edge and dividing by the speed.

The high pressure air underneath and the low pressure air on top are affected by the shape, but also by the angle of attack. By rotating the wing in relation to the incoming air, you are effectively changing the shape of the wing with regard to how air flows over it. The point where the oncoming air hits the leading edge of the wing gets lower as the angle increases, which effectively makes the air going over the top travel an even greater distance than a wing with a lower angle of attack, thereby increasing the pressure differential and increasing lift.

This is the point where the drinking straw naysayers would point out that the "wings" of an airplane are not all designed like the main wing with a flat bottom and a curved top. I say this because not all "wings" as you probably know are designed for one way lift like the main wing of an airplane. The rudder, stabilizer, and other types of airfoils need to turn in both directions and are symmetrical in crosssection....so the only way they make lift is by changing AOA. But if AOA was the sole creator of lift, then the main wing wouldn't be shaped like it is with a mostly flat bottom and a curved top. So how can some planes fly upside down? Well they simply generate enough AOA in the opposite direction from the natural lift direction to overcome those little Bernoullis zipping over the wings surface. I can promise that a fighter, with its thin, high speed wing, is a lot more nose up when flying inverted than it would be flying at the same speed while upright. The best way to think of AOA and lift is by imagining sticking your hand flat out of a car window and then angling it up and down....the wind makes your arm want to climb and descend. But just like the soda straw geeks, I could draw a diagram of how tilting your hand to change the angle of attack simply creates high pressure on one side of your hand and low pressure on the other. Its just easier to think of it as the wind hitting one side of your hand and not the other.

None of what I just typed means that the idea of Bernoulli's law creating lift is false. Its just not the whole enchilada of flying. I would hardly call the use the simplified explanation of lift to gradeschool students and laypersons a fallacy. Certainly not on the level of whether the earth is flat or not.

Very cool explanation. In your hand out of the car metaphor, this is simply Newton's 3rd law. I'm sure you've personally scene a jet flying just above water and the downwash hitting the water causes a rooster tail. Because of the downwash, there has to be an opposite force pushing "up" on the wing because of Newtons 3rd law. Just like a propeller, or helicopter rotor, or standard fan. Do you think lift or downwash plays a bigger role? Maybe this is falling into your drinking straw trap.
 

Gator2222

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Very cool explanation. In your hand out of the car metaphor, this is simply Newton's 3rd law. I'm sure you've personally scene a jet flying just above water and the downwash hitting the water causes a rooster tail. Because of the downwash, there has to be an opposite force pushing "up" on the wing because of Newtons 3rd law. Just like a propeller, or helicopter rotor, or standard fan. Do you think lift or downwash plays a bigger role? Maybe this is falling into your drinking straw trap.

"This has been a source of heated discussion over the years. In particular, there has been debate about whether lift is best explained by Bernoulli's principle or Newton's laws of motion. Modern writings agree that both Bernoulli's principle and Newton's laws are relevant and either can be used to correctly describe lift."

https://en.wikipedia.org/wiki/Berno..._principle_in_common_classroom_demonstrations

I am not qualified to make a judgement on this matter. However, I tend to always defer to Newton. Most people in today's world do not have a full appreciation of the genius of Newton.
 

AugustaGator

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"longer path/equal transit" is exactly what I was referring to in my post. It's technically not correct and yet still taught.

I'm still amazed that the Bernoulli's principle part garnered more interest than Washington not being the first president. LOL.
Not true executive under articles of confederation
 

Gator2222

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Not true executive under articles of confederation

It is an ongoing debate. It's a shame more people aren't aware of Hansen. History classes tend to miss so many subjects that may get students more interested in the subject. History doesn't have to be simply dull memorization of dates and names.
 

AugustaGator

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It is an ongoing debate. It's a shame more people aren't aware of Hansen. History classes tend to miss so many subjects that may get students more interested in the subject. History doesn't have to be simply dull memorization of dates and names.
Agree. If taught to teach vs ... what is the best phrase ... indoctrinate, we would be much wiser.
 

Zambo

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It's the drinking straw trap really. Anytime something moves its newtons law. A force is applied causing a change in inertia. An equal force is applied in the opposite direction. The thing that always makes an airfoil move is higher pressure on one side than on the other. In the case of wind hitting one side of your hand, there is high pressure there. The leeward side of your hand is protected from the wind and has low pressure. Now what a physicist would do is measure the air density, the speed of the car, the size of your hand, the angle of attack etc and come up with a coefficient of lift that could be expressed as a force in different ways. Or you could just say that the air hit my hand and blew it upward. Both are correct, one is just easier to grasp while the other would be more technically precise.

I had bernoullis law explained in physics class. They may have touched briefly on it being the basis for creating lift with a wing but I was never taught aerodynamics in physics class. Because physics was laws and equations and math, in which case you would never be able to compute the force require to lift an airplane using such a simple concept as the equal time theory.

Here is a quick and easy link that says it pretty clearly.
http://www.experimentalaircraft.info/flight-planning/aircraft-lift-formula.php
 

GatorInKnox

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"This has been a source of heated discussion over the years. In particular, there has been debate about whether lift is best explained by Bernoulli's principle or Newton's laws of motion. Modern writings agree that both Bernoulli's principle and Newton's laws are relevant and either can be used to correctly describe lift."

https://en.wikipedia.org/wiki/Bernoulli's_principle#Misapplications_of_Bernoulli.27s_principle_in_common_classroom_demonstrations

I am not qualified to make a judgement on this matter. However, I tend to always defer to Newton. Most people in today's world do not have a full appreciation of the genius of Newton.
Bernoulli's principle and Newton's laws of motion aren't at odds with each other. Bernoulli's principle is derived from them.
 

divits

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I distinctly remember being told that there would be no fluid dynamics in this thread.

giphy.gif
 

ThreatMatrix

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Well I'm not exactly sure how airplanes fly but I damn sure know how helicopters fly.
They're so damn ugly that the ground repels them.

High fives all around from my fixed wing friends.
 

ThreatMatrix

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Some better examples of the scientists getting it wrong might be light. In the 17th century Newton said it behaved as a particle. But in the 18th century Fresnel et al proved unequivocally that it behaved as a wave. And that stood for 100 years until Einstein got involved and showed that both particle theory and wave theory were copacetic. When I went to UF EE school we were taught both because both have their applications.

Another might be the Bohr's model of the atom. You know the one that shows electrons orbiting the nucleus like planets. It's a good model, good enough to arrange the periodic table by. In fact it's pretty good to use in any thing from Lasers to electronics. But Schrödinger (the Cat guy) and Heisinberg (the meth guy) came up with the electron cloud model and that is the currently accepted model.

How about gravity. Nobody can tell you what gravity is. They can tell you what it does. And we can damn sure math the hell out of it put satellites in orbit and slingshot around the earth on our way to the moon. But you can't tell me what it is. Two masses are attracted to each other? Why? Because they have mass. Yeah but why does that cause an attraction? Shut up and use this equation F = GM1M2/rr (ooh BTW that equation doesn't work inside and atom).

And don't let me get started on the direction of current flow.
 

GatorJ

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Some better examples of the scientists getting it wrong might be light. In the 17th century Newton said it behaved as a particle. But in the 18th century Fresnel et al proved unequivocally that it behaved as a wave. And that stood for 100 years until Einstein got involved and showed that both particle theory and wave theory were copacetic. When I went to UF EE school we were taught both because both have their applications.

Another might be the Bohr's model of the atom. You know the one that shows electrons orbiting the nucleus like planets. It's a good model, good enough to arrange the periodic table by. In fact it's pretty good to use in any thing from Lasers to electronics. But Schrödinger (the Cat guy) and Heisinberg (the meth guy) came up with the electron cloud model and that is the currently accepted model.

How about gravity. Nobody can tell you what gravity is. They can tell you what it does. And we can damn sure math the hell out of it put satellites in orbit and slingshot around the earth on our way to the moon. But you can't tell me what it is. Two masses are attracted to each other? Why? Because they have mass. Yeah but why does that cause an attraction? Shut up and use this equation F = GM1M2/rr (ooh BTW that equation doesn't work inside and atom).

And don't let me get started on the direction of current flow.

Well nobody has ever seen a photon. Or an atom.

But plenty of people have been to space and have seen the Earth. To have people compare that is pretty silly.
 

CapitalGator02

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I thought aircraft achieved lift because Georgia sucks. Or is that the reason why the St. Johns river flows north? Probably both
 

ThreatMatrix

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Well nobody has ever seen a photon. Or an atom.

But plenty of people have been to space and have seen the Earth. To have people compare that is pretty silly.
You have missed part of the discussion somewhere a long the way. The conversation has broadened out from the OP.
And I have seen an atom. I see photons every time they hit my eye. ;)
 

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