The earth pulls down on the plane...

....and the plane pulls up on the earth.

The air pushes up on the plane and the plane pushes down on the air;
essentially transferring the earth's continuous flow of downward
momentum acting on the plane to a much greater mass of air.

That air keeps that downward momentum, diffusing it through more and
more volume...

....until it eventually transfers it back to the Earth; countering the
aircraft's upward pull on it.

I'm willing to send that to any Ph.D. in Aeronautics that anyone cares
to name and post the answer back here.

Anyone game?

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg

Alan Baker wrote:
...and the plane pulls up on the earth.

The air pushes up on the plane and the plane pushes down on the air;
essentially transferring the earth's continuous flow of downward
momentum acting on the plane to a much greater mass of air.

That air keeps that downward momentum, diffusing it through more and
more volume...

...until it eventually transfers it back to the Earth; countering the
aircraft's upward pull on it.

I'm willing to send that to any Ph.D. in Aeronautics that anyone cares
to name and post the answer back here.

Anyone game?

LOL

Alan Baker wrote:
...and the plane pulls up on the earth.

The air pushes up on the plane and the plane pushes down on the air;
essentially transferring the earth's continuous flow of downward
momentum acting on the plane to a much greater mass of air.

That air keeps that downward momentum, diffusing it through more and
more volume...

...until it eventually transfers it back to the Earth; countering the
aircraft's upward pull on it.

I'm willing to send that to any Ph.D. in Aeronautics that anyone cares
to name and post the answer back here.

Anyone game?

Send that to Scott Eberhardt.

http://home.comcast.net/~clipper-108/Professional.html
To email me:
Copy/Paste Send


Next, don't miss "A slightly more technical paper, which targets physics
students and teachers, titled The Newtonian Description of Lift of a
Wing, is also available online (in PDF format)" at the bottom of the
webpage. You'll notice his email address at the top of that paper, the
same as on the webpage.

As the paper says, the amount of air below that is pushed is negligible.
See "the wrong-Newtonian description of lift" on page 3.

See the "virtual scoop" in Figure 5. Air from overhead is pulled down by
the plane. The plane must, in turn, be pulled up. You imagined a plane
at the top of an air column, pushing down. It's more like a plane at the
bottom of a suction bubble, pulling down. Oh, you like differential
pressure, you don't like air to pull? Too bad, he talks about air
pulling on page 5.

Nothing is said about downwash continuing to the surface. The paper does
say that if a plane flies over a large scale, the weight of the airplane
would be measured. Excited?
Well, an acoustically levitated scale would register its own weight too.
Or turn that upside down, and the scale sees the earth's weight
acoustically levitated above the scale. Same thing, and no upwash or
downwash in sight, just a standing pressure wave with a scale caught at
a node between positive and negative.
Almost sort of like a wing between a strong little suction bubble and a
big weak pressure bubble. Is the wing almost sort of caught in a
standing wave? I don't know.

In article ,
Beryl wrote:

Alan Baker wrote:
...and the plane pulls up on the earth.

The air pushes up on the plane and the plane pushes down on the air;
essentially transferring the earth's continuous flow of downward
momentum acting on the plane to a much greater mass of air.

That air keeps that downward momentum, diffusing it through more and
more volume...

...until it eventually transfers it back to the Earth; countering the
aircraft's upward pull on it.

I'm willing to send that to any Ph.D. in Aeronautics that anyone cares
to name and post the answer back here.

Anyone game?

Send that to Scott Eberhardt.

OK, I will.


http://home.comcast.net/~clipper-108/Professional.html
To email me:
Copy/Paste Send

Thanks, I've got it covered.



Next, don't miss "A slightly more technical paper, which targets physics
students and teachers, titled The Newtonian Description of Lift of a
Wing, is also available online (in PDF format)" at the bottom of the
webpage. You'll notice his email address at the top of that paper, the
same as on the webpage.

As the paper says, the amount of air below that is pushed is negligible.
See "the wrong-Newtonian description of lift" on page 3.

See the "virtual scoop" in Figure 5. Air from overhead is pulled down by
the plane. The plane must, in turn, be pulled up. You imagined a plane
at the top of an air column, pushing down. It's more like a plane at the
bottom of a suction bubble, pulling down. Oh, you like differential
pressure, you don't like air to pull? Too bad, he talks about air
pulling on page 5.

Nothing is said about downwash continuing to the surface. The paper does
say that if a plane flies over a large scale, the weight of the airplane
would be measured. Excited?
Well, an acoustically levitated scale would register its own weight too.
Or turn that upside down, and the scale sees the earth's weight
acoustically levitated above the scale. Same thing, and no upwash or
downwash in sight, just a standing pressure wave with a scale caught at
a node between positive and negative.
Almost sort of like a wing between a strong little suction bubble and a
big weak pressure bubble. Is the wing almost sort of caught in a
standing wave? I don't know.


You certainly don't.

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg

In article ,
Beryl wrote:

Alan Baker wrote:
...and the plane pulls up on the earth.

The air pushes up on the plane and the plane pushes down on the air;
essentially transferring the earth's continuous flow of downward
momentum acting on the plane to a much greater mass of air.

That air keeps that downward momentum, diffusing it through more and
more volume...

...until it eventually transfers it back to the Earth; countering the
aircraft's upward pull on it.

I'm willing to send that to any Ph.D. in Aeronautics that anyone cares
to name and post the answer back here.

Anyone game?

Send that to Scott Eberhardt.

http://home.comcast.net/~clipper-108/Professional.html
To email me:
Copy/Paste Send


Next, don't miss "A slightly more technical paper, which targets physics
students and teachers, titled The Newtonian Description of Lift of a
Wing, is also available online (in PDF format)" at the bottom of the
webpage. You'll notice his email address at the top of that paper, the
same as on the webpage.

As the paper says, the amount of air below that is pushed is negligible.
See "the wrong-Newtonian description of lift" on page 3.

See the "virtual scoop" in Figure 5. Air from overhead is pulled down by
the plane. The plane must, in turn, be pulled up. You imagined a plane
at the top of an air column, pushing down. It's more like a plane at the
bottom of a suction bubble, pulling down. Oh, you like differential
pressure, you don't like air to pull? Too bad, he talks about air
pulling on page 5.

Nothing is said about downwash continuing to the surface. The paper does
say that if a plane flies over a large scale, the weight of the airplane
would be measured. Excited?
Well, an acoustically levitated scale would register its own weight too.
Or turn that upside down, and the scale sees the earth's weight
acoustically levitated above the scale. Same thing, and no upwash or
downwash in sight, just a standing pressure wave with a scale caught at
a node between positive and negative.
Almost sort of like a wing between a strong little suction bubble and a
big weak pressure bubble. Is the wing almost sort of caught in a
standing wave? I don't know.

Oh, you should check out what he says in his book:

"The wing develops lift by transferring momentum to the air. Momentum is
mass times velocity. In straight and level flight, the momentum is
transferred toward the earth. This momentum eventually strikes the
earth."

http://books.google.com/books?id=wmu...ntcover&dq=und
erstanding+flight+anderson&cd=1#v=onepage&q=downwa sh&f=false

Page 11.

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
...and the plane pulls up on the earth.

The air pushes up on the plane and the plane pushes down on the air;
essentially transferring the earth's continuous flow of downward
momentum acting on the plane to a much greater mass of air.

That air keeps that downward momentum, diffusing it through more and
more volume...

...until it eventually transfers it back to the Earth; countering the
aircraft's upward pull on it.

I'm willing to send that to any Ph.D. in Aeronautics that anyone cares
to name and post the answer back here.

Anyone game?
Send that to Scott Eberhardt.

http://home.comcast.net/~clipper-108/Professional.html
To email me:
Copy/Paste Send


Next, don't miss "A slightly more technical paper, which targets physics
students and teachers, titled The Newtonian Description of Lift of a
Wing, is also available online (in PDF format)" at the bottom of the
webpage. You'll notice his email address at the top of that paper, the
same as on the webpage.

As the paper says, the amount of air below that is pushed is negligible.
See "the wrong-Newtonian description of lift" on page 3.

See the "virtual scoop" in Figure 5. Air from overhead is pulled down by
the plane. The plane must, in turn, be pulled up. You imagined a plane
at the top of an air column, pushing down. It's more like a plane at the
bottom of a suction bubble, pulling down. Oh, you like differential
pressure, you don't like air to pull? Too bad, he talks about air
pulling on page 5.

Nothing is said about downwash continuing to the surface. The paper does
say that if a plane flies over a large scale, the weight of the airplane
would be measured. Excited?
Well, an acoustically levitated scale would register its own weight too.
Or turn that upside down, and the scale sees the earth's weight
acoustically levitated above the scale. Same thing, and no upwash or
downwash in sight, just a standing pressure wave with a scale caught at
a node between positive and negative.
Almost sort of like a wing between a strong little suction bubble and a
big weak pressure bubble. Is the wing almost sort of caught in a
standing wave? I don't know.

Oh, you should check out what he says in his book:

"The wing develops lift by transferring momentum to the air. Momentum is
mass times velocity. In straight and level flight, the momentum is
transferred toward the earth. This momentum eventually strikes the
earth."

http://books.google.com/books?id=wmu...ntcover&dq=und
erstanding+flight+anderson&cd=1#v=onepage&q=downwa sh&f=false

Page 11.

Er, right. His book "which targets the general public", rather than the
more technical paper "which targets physics students and teachers."

In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
...and the plane pulls up on the earth.

The air pushes up on the plane and the plane pushes down on the air;
essentially transferring the earth's continuous flow of downward
momentum acting on the plane to a much greater mass of air.

That air keeps that downward momentum, diffusing it through more and
more volume...

...until it eventually transfers it back to the Earth; countering the
aircraft's upward pull on it.

I'm willing to send that to any Ph.D. in Aeronautics that anyone cares
to name and post the answer back here.

Anyone game?
Send that to Scott Eberhardt.

http://home.comcast.net/~clipper-108/Professional.html
To email me:
Copy/Paste Send


Next, don't miss "A slightly more technical paper, which targets physics
students and teachers, titled The Newtonian Description of Lift of a
Wing, is also available online (in PDF format)" at the bottom of the
webpage. You'll notice his email address at the top of that paper, the
same as on the webpage.

As the paper says, the amount of air below that is pushed is negligible.
See "the wrong-Newtonian description of lift" on page 3.

See the "virtual scoop" in Figure 5. Air from overhead is pulled down by
the plane. The plane must, in turn, be pulled up. You imagined a plane
at the top of an air column, pushing down. It's more like a plane at the
bottom of a suction bubble, pulling down. Oh, you like differential
pressure, you don't like air to pull? Too bad, he talks about air
pulling on page 5.

Nothing is said about downwash continuing to the surface. The paper does
say that if a plane flies over a large scale, the weight of the airplane
would be measured. Excited?
Well, an acoustically levitated scale would register its own weight too.
Or turn that upside down, and the scale sees the earth's weight
acoustically levitated above the scale. Same thing, and no upwash or
downwash in sight, just a standing pressure wave with a scale caught at
a node between positive and negative.
Almost sort of like a wing between a strong little suction bubble and a
big weak pressure bubble. Is the wing almost sort of caught in a
standing wave? I don't know.

Oh, you should check out what he says in his book:

"The wing develops lift by transferring momentum to the air. Momentum is
mass times velocity. In straight and level flight, the momentum is
transferred toward the earth. This momentum eventually strikes the
earth."

http://books.google.com/books?id=wmu...ntcover&dq=und
erstanding+flight+anderson&cd=1#v=onepage&q=downwa sh&f=false

Page 11.

Er, right. His book "which targets the general public", rather than the
more technical paper "which targets physics students and teachers."

You think he rights things into his book which aren't true? You think
that simply because he makes the language more plain he's included
falsehoods?

Really?

He never says *once* in his "more technical paper" that "The plane must,
in turn, be pulled up." That is you.

He does say in his "more technical paper":

"Lift requires power

When a plane passes overhead the formally still air gains a downward
velocity."

Read that over and over until you get it:

"When a plane passes overhead the formally still air gains a downward
velocity."

He also says right at the top of this "more techical paper":

"This material can be found in more detail in Understanding Flight 1st
and 2nd editions by David Anderson and Scott Eberhardt, McGraw-Hill,
2001, and 2009"

IOW, the author of the "more technical paper" declares the book the more
detailed explanation.

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
...and the plane pulls up on the earth.

The air pushes up on the plane and the plane pushes down on the air;
essentially transferring the earth's continuous flow of downward
momentum acting on the plane to a much greater mass of air.

That air keeps that downward momentum, diffusing it through more and
more volume...

...until it eventually transfers it back to the Earth; countering the
aircraft's upward pull on it.

I'm willing to send that to any Ph.D. in Aeronautics that anyone cares
to name and post the answer back here.

Anyone game?
Send that to Scott Eberhardt.

http://home.comcast.net/~clipper-108/Professional.html
To email me:
Copy/Paste Send


Next, don't miss "A slightly more technical paper, which targets physics
students and teachers, titled The Newtonian Description of Lift of a
Wing, is also available online (in PDF format)" at the bottom of the
webpage. You'll notice his email address at the top of that paper, the
same as on the webpage.

As the paper says, the amount of air below that is pushed is negligible.
See "the wrong-Newtonian description of lift" on page 3.

See the "virtual scoop" in Figure 5. Air from overhead is pulled down by
the plane. The plane must, in turn, be pulled up. You imagined a plane
at the top of an air column, pushing down. It's more like a plane at the
bottom of a suction bubble, pulling down. Oh, you like differential
pressure, you don't like air to pull? Too bad, he talks about air
pulling on page 5.

Nothing is said about downwash continuing to the surface. The paper does
say that if a plane flies over a large scale, the weight of the airplane
would be measured. Excited?
Well, an acoustically levitated scale would register its own weight too.
Or turn that upside down, and the scale sees the earth's weight
acoustically levitated above the scale. Same thing, and no upwash or
downwash in sight, just a standing pressure wave with a scale caught at
a node between positive and negative.
Almost sort of like a wing between a strong little suction bubble and a
big weak pressure bubble. Is the wing almost sort of caught in a
standing wave? I don't know.
Oh, you should check out what he says in his book:

"The wing develops lift by transferring momentum to the air. Momentum is
mass times velocity. In straight and level flight, the momentum is
transferred toward the earth. This momentum eventually strikes the
earth."

http://books.google.com/books?id=wmu...ntcover&dq=und
erstanding+flight+anderson&cd=1#v=onepage&q=downwa sh&f=false

Page 11.
Er, right. His book "which targets the general public", rather than the
more technical paper "which targets physics students and teachers."

You think he rights things into his book which aren't true? You think
that simply because he makes the language more plain he's included
falsehoods?

Really?

I think so.

He never says *once* in his "more technical paper" that "The plane must,
in turn, be pulled up." That is you.

Correct. He never said the next sentence "You imagined a plane at the
top of an air column, pushing down" either.

He does say in his "more technical paper":

"Lift requires power

When a plane passes overhead the formally still air gains a downward
velocity."

Read that over and over until you get it:

"When a plane passes overhead the formally still air gains a downward
velocity."

He actually says that? Still air always seems very casual to me.

He also says right at the top of this "more techical paper":

"This material can be found in more detail in Understanding Flight 1st
and 2nd editions by David Anderson and Scott Eberhardt, McGraw-Hill,
2001, and 2009"

Not on the pdf I downloaded.
http://home.comcast.net/~clipper-108/Lift_AAPT.pdf
Maybe you're looking at something else.

IOW, the author of the "more technical paper" declares the book the more
detailed explanation.

I don't see any such notion on his webpage either.

Alan Baker wrote:
Oh, you should check out what he says in his book:

"The wing develops lift by transferring momentum to the air. Momentum
is mass times velocity. In straight and level flight, the momentum is
transferred toward the earth. This momentum eventually strikes the
earth."

The momentum is transferred toward the earth at essentially the speed of
sound and appears as a rise in static pressure.

.... OR ...

_Your_ contention has *always* been that it is transferred much slower.
In fact you contend that the speed of that transfer decreases at some
unknown rate. By inference, it seems you also appear to contend that the
transfer eventually happens due to a rise in dynamic pressure, not static
pressure.

You appear to continue to treat the problem as a "rocket" problem, which
yields non-physical aspects like holes and voids in the atmosphere above
the aircraft. (Because you've already claimed no air moves upward *until*
the downwash reaches the earth's surface.)

So please help me understand your view of the situation by considering
the following hypothetical case and answering as many of the questions I
ask as you can:

Imagine a toy helicopter in a large room (or even a vertically oriented
denser-than-water submarine in a box fully filled with water):

========================== -- Top
| |
| |
B -- | --------- | -- B
| | |
| (===0 |
| |
... ... (Height of room/box could be large or
| | small, relative to blade width.)
| |
========================== -- Bottom
(Width of room/box could be large or
small, relative to blade width.)

Given a downwash through the blades (depicted by "---------" in the
figure above) of the copter/submarine sufficient to hold the
copter/submarine stationary, can you describe to me roughly how you see
the flow of fluid above the helicopter occuring such that no fluid flows
upward anywhere *through* the plane "B" made by the blades *before* the
first bit of downwash created by the *blades* has reached the bottom of
the room/box?

That is - if the copter/submarine begins moving 1 kg/s of fluid down, do
you see a void immediately forming above the blades?

If not, which direction is the fluid flowing from so as to keep a void
from forming? If so, what keeps fluid from filling that void?

If a void above the blades is avoided by sideways fluid flow, does
that mean you see voids forming along the walls above the blades?

If you see voids forming anywhere, what keeps fluid from filling
them?

Are voids consistent with the assumption of incompressible flow?

Alan Baker wrote:
Oh, you should check out what he says in his book:

"The wing develops lift by transferring momentum to the air. Momentum
is mass times velocity. In straight and level flight, the momentum is
transferred toward the earth. This momentum eventually strikes the
earth."

The momentum is transferred toward the earth at essentially the speed of
sound and appears as a rise in static pressure.

.... OR ...

_Your_ contention has *always* been that it is transferred much slower.
In fact you contend that the speed of that transfer decreases at some
unknown rate. By inference, it seems you also appear to contend that the
transfer eventually happens due to a rise in dynamic pressure, not static
pressure.

You appear to continue to treat the problem as a "rocket" problem, which
yields non-physical aspects like holes and voids in the atmosphere above
the aircraft. (Because you've already claimed no air moves upward *until*
the downwash reaches the earth's surface.)

So please help me understand your view of the situation by considering
the following hypothetical case and answering as many of the questions I
ask as you can:

Imagine a toy helicopter in a large room (or even a vertically oriented
denser-than-water submarine in a box fully filled with water):

========================== -- Top
| |
| |
B -- | --------- | -- B
| | |
| (===0 |
| |
... ... (Height of room/box could be large or
| | small, relative to blade width.)
| |
========================== -- Bottom
(Width of room/box could be large or
small, relative to blade width.)

Given a downwash through the blades (depicted by "---------" in the
figure above) of the copter/submarine sufficient to hold the
copter/submarine stationary, can you describe to me roughly how you see
the flow of fluid above the helicopter occuring such that no fluid flows
upward anywhere *through* the plane "B" made by the blades *before* the
first bit of downwash created by the *blades* has reached the bottom of
the room/box?

That is - if the copter/submarine begins moving 1 kg/s of fluid down, do
you see a void immediately forming above the blades?

If not, which direction is the fluid flowing from so as to keep a void
from forming? If so, what keeps fluid from filling that void?

If a void above the blades is avoided by sideways fluid flow, does
that mean you see voids forming along the walls above the blades?

If you see voids forming anywhere, what keeps fluid from filling
them?

Are voids consistent with the assumption of incompressible flow?