Cambridge scientist debunks flying myth
01-30-2012, 07:53 AM
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Cambridge scientist debunks flying myth
01-30-2012, 09:14 AM
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RE: Cambridge scientist debunks flying myth
As usual, The Telegraph, like most media, only reports part of the story. For Prof. Babinsky's full article, go to the following link:
http://iopscience.iop.org/0031-9120/...0_38_6_001.pdf
You will find a very well written and insightful explanation of "How do wings work?"
I also think that the comments on this post will go on and on and on infinitum
http://iopscience.iop.org/0031-9120/...0_38_6_001.pdf
You will find a very well written and insightful explanation of "How do wings work?"
I also think that the comments on this post will go on and on and on infinitum
01-31-2012, 12:07 AM
#4
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RE: Cambridge scientist debunks flying myth
I am no mathematician..........but my foam park flyer airplanes with flat bottomed wing with positive cambered upper surface sure make a long, shallow, gentle glide after I cut the power off while beginning the landing circuit. My foam Dynam Extra 330 Park flyer with symmetrical wing camber on the bottom surface and on the upper surface has to be landed with 1/4 throttle, otherwise it sinks too fast on power off landings. The symmetrical airfoil on my Dynam Extra 330 park flyer develops lift only when there is angle of attack on the wing........and this angle of attack to generate lift on the symmetrical airfoil kills the airspeed very quickly, requiring 1/4 throttle. All I know is that the flat bottomed wing with positive cambered upper surface is a floater..........All of these to ask the question, why do some high wing foam park flyers like the Exceed J3 Cub, have a wing with NEGATIVE CAMBERED BOTTOM SURFACE and a positive cambered upper surface. What is the advantage of this versus a flat bottomed wing with a positive cambered upper surface????? What is the advantage of the negative cambered bottom surface wing??? Larry.
01-31-2012, 12:26 AM
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RE: Cambridge scientist debunks flying myth
A subject very well covered in this on-line book. http://www.av8n.com/how/ Very good reading for us RC'ers though written for full scale.
Bedford
Bedford
01-31-2012, 10:57 AM
#6
RE: Cambridge scientist debunks flying myth
I disagree with Robin.
I think Prof Babinsky's article is rather a poor explanation. Anyone capable of understanding it will already know the facts he is trying to expose.
Try quoting this on your modelflying field "discussing the existence of transverse pressure gradients in curved streamlines and applying this knowledge to the flowfield around an aerofoil"
That is his way of debunking the myth perpetuated by people blowing over a sheet of paper.
We all already know that has nothing to do with Bernoulli, and where exactly does it say that air molecules must begin and end their passages above and below the wing exactly together?
His approach is more concerned with pouring scorn on others, who are trying to keep it simple, than in explaining simply himself.
When I covered this in my book "Basic Aeronautics for Modellers" I tried hard not to scorn the efforts of others, while trying hard not to fall into the abyss of popular myth.
My Figure 2.3 is a diagram very similar to his Figure 4, and I hope I put over a similar message, butwithout his greek letters and formulae.
The Telegraph article, typical of sensational ill informed journalism, turns up the scorn and turns the informative value right down.
I think Prof Babinsky's article is rather a poor explanation. Anyone capable of understanding it will already know the facts he is trying to expose.
Try quoting this on your modelflying field "discussing the existence of transverse pressure gradients in curved streamlines and applying this knowledge to the flowfield around an aerofoil"
That is his way of debunking the myth perpetuated by people blowing over a sheet of paper.
We all already know that has nothing to do with Bernoulli, and where exactly does it say that air molecules must begin and end their passages above and below the wing exactly together?
His approach is more concerned with pouring scorn on others, who are trying to keep it simple, than in explaining simply himself.
When I covered this in my book "Basic Aeronautics for Modellers" I tried hard not to scorn the efforts of others, while trying hard not to fall into the abyss of popular myth.
My Figure 2.3 is a diagram very similar to his Figure 4, and I hope I put over a similar message, butwithout his greek letters and formulae.
The Telegraph article, typical of sensational ill informed journalism, turns up the scorn and turns the informative value right down.
01-31-2012, 12:29 PM
#7
RE: Cambridge scientist debunks flying myth
ANY shape which produces difference in pressure as it travels thru the air - will create lift
All of these endless theories just describe part of what is happening
a flat plate is a perfectly good shape for many aircraft.
All of these endless theories just describe part of what is happening
a flat plate is a perfectly good shape for many aircraft.
02-01-2012, 10:15 AM
#8
RE: Cambridge scientist debunks flying myth
ORIGINAL: larrysogla
What is the advantage of this versus a flat bottomed wing with a positive cambered upper surface????? What is the advantage of the negative cambered bottom surface wing??? Larry.
What is the advantage of this versus a flat bottomed wing with a positive cambered upper surface????? What is the advantage of the negative cambered bottom surface wing??? Larry.
The advantage is that, keeping everything else the same: AOA, dimensions, velocity, etc.) it scoops more volume of air, producing a higher pressure differential and consequent higher lift.
Because nothing is free, that advantage comes with a disadvantage: higher lift means higher drag, always,......and drag grows with the square of the velocity.
For that reason, those airfoils are more appropriated for low velocity applications, like bi-planes and sailplanes.
02-01-2012, 01:20 PM
#9
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RE: Cambridge scientist debunks flying myth
ORIGINAL: alasdair
I disagree with Robin.
I think Prof Babinsky's article is rather a poor explanation. Anyone capable of understanding it will already know the facts he is trying to expose.
Try quoting this on your model flying field ''discussing the existence of transverse pressure gradients in curved streamlines and applying this knowledge to the flowfield around an aerofoil''
That is his way of debunking the myth perpetuated by people blowing over a sheet of paper.
We all already know that has nothing to do with Bernoulli, and where exactly does it say that air molecules must begin and end their passages above and below the wing exactly together?
His approach is more concerned with pouring scorn on others, who are trying to keep it simple, than in explaining simply himself.
When I covered this in my book ''Basic Aeronautics for Modellers'' I tried hard not to scorn the efforts of others, while trying hard not to fall into the abyss of popular myth.
My Figure 2.3 is a diagram very similar to his Figure 4, and I hope I put over a similar message, but without his greek letters and formulae.
The Telegraph article, typical of sensational ill informed journalism, turns up the scorn and turns the informative value right down.
I disagree with Robin.
I think Prof Babinsky's article is rather a poor explanation. Anyone capable of understanding it will already know the facts he is trying to expose.
Try quoting this on your model flying field ''discussing the existence of transverse pressure gradients in curved streamlines and applying this knowledge to the flowfield around an aerofoil''
That is his way of debunking the myth perpetuated by people blowing over a sheet of paper.
We all already know that has nothing to do with Bernoulli, and where exactly does it say that air molecules must begin and end their passages above and below the wing exactly together?
His approach is more concerned with pouring scorn on others, who are trying to keep it simple, than in explaining simply himself.
When I covered this in my book ''Basic Aeronautics for Modellers'' I tried hard not to scorn the efforts of others, while trying hard not to fall into the abyss of popular myth.
My Figure 2.3 is a diagram very similar to his Figure 4, and I hope I put over a similar message, but without his greek letters and formulae.
The Telegraph article, typical of sensational ill informed journalism, turns up the scorn and turns the informative value right down.
NASA has a whole bunch of information on their website on the subject of lift. Koanda plays prominently in the NASA treatise and is practically omitted in the above article. There was a hint of a suggestion of its existence in the statement that air flow sticks to and follows a curved surface......Lift generated by pressure differential is a certain percent of the whole, but not 100%; Delta P is but one component of the total amount of lift required to lift any wing
02-02-2012, 02:25 PM
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RE: Cambridge scientist debunks flying myth
If you aren't moving air downward and accelerating it as well, you aren't going to lift. It's action and reaction, meaning it's Newton. Don't get thick headed about this. The concept requires no rocket science.
Stand under a helicopter, or behind a prop, and feel the physics. (Rotors and props are rotating wings)
Read "Understanding Flight" by David F. Anderson and Scott Eberhardt for more on this.
Stand under a helicopter, or behind a prop, and feel the physics. (Rotors and props are rotating wings)
Read "Understanding Flight" by David F. Anderson and Scott Eberhardt for more on this.
02-02-2012, 05:43 PM
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RE: Cambridge scientist debunks flying myth
I am a "touch and go" kind of guy.......and the symmetrical airfoil wings on my planes are "power on " landings................I am more partial to the positive cambered, flat bottomed wings that land on a gentle glide with power off.............. Those are my Cessna's, I like to relax when I am flying and those high lift Cessna wings fill the ticket for me. I am a lazy kind of guy, I guess. I like it slow and gentle. Larry.
02-03-2012, 03:59 AM
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RE: Cambridge scientist debunks flying myth
ORIGINAL: Lnewqban
higher lift means higher drag, always,...
higher lift means higher drag, always,...
ORIGINAL: Lnewqban
...and drag grows with the square of the velocity.
...and drag grows with the square of the velocity.
The basic equation for drag (drag = 1/2 * density * true_airspeed^2 * reference_area * drag_coefficient) can mislead you. In the case where you maintain Weight = Lift, the drag coefficient is also a function of airspeed, so drag is not simply proportional to the square of velocity.
02-03-2012, 04:15 AM
#15
RE: Cambridge scientist debunks flying myth
MTK, Take it in context.
Robin asked the question "What do you think?" so I wrote it. I don't intend to be quoted in the Telegraph. [there's no B in MTK. You're not Babinsky?]
When I did go into print I tried to be positive, I tried to avoid big scientific words and formulae, I tried to avoid disparaging other writers, and I tried to avoid writing stuff that was popular knowledge but untrue. (Babinsky just aimed for that last one)
I also tried to avoid the concept of "owning" the ideas put forward.
I make little reference to the Coanda effect (not Koanda btw) because although it can be used anecdotally to explain how airflow curves around an airfoil, which can explain Lift, I have never seen it used quantitatively. I have never seen Coanda used to explain lift in equations and numbers. Has anyone else?
Your statement
"Lift generated by pressure differential is a certain percent of the whole, but not 100%; Delta P is but one component of the total amount of lift required to lift any wing "
needs backup.
As far as I was aware, the Resultant Aerodynamic force on a wing (or whatever) is the integral of the air pressure over the surface, and Lift was defined as the component of aerodynamic force at right angles to the direction of motion. The pressure integral omits skin friction I suppose, so have I missed something? Are they getting lift from skin friction Drag? That's magic! Or, Has someone invented "Magic Lift" that does not need a surface to push on?
Can anyone supply a reference that explains Lift that is not generated by air pressure?
Robin asked the question "What do you think?" so I wrote it. I don't intend to be quoted in the Telegraph. [there's no B in MTK. You're not Babinsky?]
When I did go into print I tried to be positive, I tried to avoid big scientific words and formulae, I tried to avoid disparaging other writers, and I tried to avoid writing stuff that was popular knowledge but untrue. (Babinsky just aimed for that last one)
I also tried to avoid the concept of "owning" the ideas put forward.
I make little reference to the Coanda effect (not Koanda btw) because although it can be used anecdotally to explain how airflow curves around an airfoil, which can explain Lift, I have never seen it used quantitatively. I have never seen Coanda used to explain lift in equations and numbers. Has anyone else?
Your statement
"Lift generated by pressure differential is a certain percent of the whole, but not 100%; Delta P is but one component of the total amount of lift required to lift any wing "
needs backup.
As far as I was aware, the Resultant Aerodynamic force on a wing (or whatever) is the integral of the air pressure over the surface, and Lift was defined as the component of aerodynamic force at right angles to the direction of motion. The pressure integral omits skin friction I suppose, so have I missed something? Are they getting lift from skin friction Drag? That's magic! Or, Has someone invented "Magic Lift" that does not need a surface to push on?
Can anyone supply a reference that explains Lift that is not generated by air pressure?
02-03-2012, 05:29 AM
#16
RE: Cambridge scientist debunks flying myth
ORIGINAL: alasdair
MTK, Take it in context.
Robin asked the question ''What do you think?'' so I wrote it. I don't intend to be quoted in the Telegraph. [there's no B in MTK. You're not Babinsky?]
When I did go into print I tried to be positive, I tried to avoid big scientific words and formulae, I tried to avoid disparaging other writers, and I tried to avoid writing stuff that was popular knowledge but untrue. (Babinsky just aimed for that last one)
I also tried to avoid the concept of ''owning'' the ideas put forward.
I make little reference to the Coanda effect (not Koanda btw) because although it can be used anecdotally to explain how airflow curves around an airfoil, which can explain Lift, I have never seen it used quantitatively. I have never seen Coanda used to explain lift in equations and numbers. Has anyone else?
Your statement
''Lift generated by pressure differential is a certain percent of the whole, but not 100%; Delta P is but one component of the total amount of lift required to lift any wing ''
needs backup.
As far as I was aware, the Resultant Aerodynamic force on a wing (or whatever) is the integral of the air pressure over the surface, and Lift was defined as the component of aerodynamic force at right angles to the direction of motion. The pressure integral omits skin friction I suppose, so have I missed something? Are they getting lift from skin friction Drag? That's magic! Or, Has someone invented ''Magic Lift'' that does not need a surface to push on?
Can anyone supply a reference that explains Lift that is not generated by air pressure?
MTK, Take it in context.
Robin asked the question ''What do you think?'' so I wrote it. I don't intend to be quoted in the Telegraph. [there's no B in MTK. You're not Babinsky?]
When I did go into print I tried to be positive, I tried to avoid big scientific words and formulae, I tried to avoid disparaging other writers, and I tried to avoid writing stuff that was popular knowledge but untrue. (Babinsky just aimed for that last one)
I also tried to avoid the concept of ''owning'' the ideas put forward.
I make little reference to the Coanda effect (not Koanda btw) because although it can be used anecdotally to explain how airflow curves around an airfoil, which can explain Lift, I have never seen it used quantitatively. I have never seen Coanda used to explain lift in equations and numbers. Has anyone else?
Your statement
''Lift generated by pressure differential is a certain percent of the whole, but not 100%; Delta P is but one component of the total amount of lift required to lift any wing ''
needs backup.
As far as I was aware, the Resultant Aerodynamic force on a wing (or whatever) is the integral of the air pressure over the surface, and Lift was defined as the component of aerodynamic force at right angles to the direction of motion. The pressure integral omits skin friction I suppose, so have I missed something? Are they getting lift from skin friction Drag? That's magic! Or, Has someone invented ''Magic Lift'' that does not need a surface to push on?
Can anyone supply a reference that explains Lift that is not generated by air pressure?
makes no difference how it occurs
02-03-2012, 06:00 AM
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RE: Cambridge scientist debunks flying myth
ORIGINAL: MTK
Lift generated by pressure differential is a certain percent of the whole, but not 100%; Delta P is but one component of the total amount of lift required to lift any wing
Lift generated by pressure differential is a certain percent of the whole, but not 100%; Delta P is but one component of the total amount of lift required to lift any wing
Motion of the air away from the wing DOES affect the aerodynamic force acting on the wing, but only by influencing the stresses on the surface of the wing.
The confusion usually arises because it is sometimes convenient (and accurate) to identify different mechanisms that contribute to the lift or drag on a wing. You can identify different mechanisms that contribute to the "lift generated by pressure differential", but you cannot (accurately) identify "lift generated by pressure differential" as a component of the total lift... it IS the total lift.
02-03-2012, 06:01 AM
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RE: Cambridge scientist debunks flying myth
Effectively, I asked ''What do you think?", lol..., because I had some doubts about the article... Still, you post (all of you) very interesting informations about lift and airfoils, It is very educative... ;-). I'm not an expert in aerodynamic... Still and forever learning... Thanks...
02-04-2012, 09:16 AM
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RE: Cambridge scientist debunks flying myth
ORIGINAL: rmh
No- simply because lift is -simply- a result of unequal pressures at work
makes no difference how it occurs
ORIGINAL: alasdair
MTK, Take it in context.
Robin asked the question ''What do you think?'' so I wrote it. I don't intend to be quoted in the Telegraph. [there's no B in MTK. You're not Babinsky?]
When I did go into print I tried to be positive, I tried to avoid big scientific words and formulae, I tried to avoid disparaging other writers, and I tried to avoid writing stuff that was popular knowledge but untrue. (Babinsky just aimed for that last one)
I also tried to avoid the concept of ''owning'' the ideas put forward.
I make little reference to the Coanda effect (not Koanda btw) because although it can be used anecdotally to explain how airflow curves around an airfoil, which can explain Lift, I have never seen it used quantitatively. I have never seen Coanda used to explain lift in equations and numbers. Has anyone else?
Your statement
''Lift generated by pressure differential is a certain percent of the whole, but not 100%; Delta P is but one component of the total amount of lift required to lift any wing ''
needs backup.
As far as I was aware, the Resultant Aerodynamic force on a wing (or whatever) is the integral of the air pressure over the surface, and Lift was defined as the component of aerodynamic force at right angles to the direction of motion. The pressure integral omits skin friction I suppose, so have I missed something? Are they getting lift from skin friction Drag? That's magic! Or, Has someone invented ''Magic Lift'' that does not need a surface to push on?
Can anyone supply a reference that explains Lift that is not generated by air pressure?
MTK, Take it in context.
Robin asked the question ''What do you think?'' so I wrote it. I don't intend to be quoted in the Telegraph. [there's no B in MTK. You're not Babinsky?]
When I did go into print I tried to be positive, I tried to avoid big scientific words and formulae, I tried to avoid disparaging other writers, and I tried to avoid writing stuff that was popular knowledge but untrue. (Babinsky just aimed for that last one)
I also tried to avoid the concept of ''owning'' the ideas put forward.
I make little reference to the Coanda effect (not Koanda btw) because although it can be used anecdotally to explain how airflow curves around an airfoil, which can explain Lift, I have never seen it used quantitatively. I have never seen Coanda used to explain lift in equations and numbers. Has anyone else?
Your statement
''Lift generated by pressure differential is a certain percent of the whole, but not 100%; Delta P is but one component of the total amount of lift required to lift any wing ''
needs backup.
As far as I was aware, the Resultant Aerodynamic force on a wing (or whatever) is the integral of the air pressure over the surface, and Lift was defined as the component of aerodynamic force at right angles to the direction of motion. The pressure integral omits skin friction I suppose, so have I missed something? Are they getting lift from skin friction Drag? That's magic! Or, Has someone invented ''Magic Lift'' that does not need a surface to push on?
Can anyone supply a reference that explains Lift that is not generated by air pressure?
makes no difference how it occurs
Stand behind a prop, and feel the physics.
Newton states that for every action, there's a reaction. So logic dictates that since wings move air down while also accelerating that same air, then the wing reacts with an opposing force in the opposite direction - AKA lift.
Stand under a helicopter, and feel the physics.
No one can demonstrate lift through the miracle of pressure differentials only - not without also thrusting air down. The pressure differentials are just what happens when air moves anywhere. They are a red herring, provided by 60 years of disinformation in our textbooks. The new and correct thinking is what I stated above.
And, if something's thrusting air down (hold onto your biggest plane with the props running full and feel the physics), then that something is reacting to it.
You cannot deny Newton.
02-04-2012, 09:44 AM
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RE: Cambridge scientist debunks flying myth
ORIGINAL: Tim Green
Nawww - it's Newton.
Stand behind a prop, and feel the physics.
Newton states that for every action, there's a reaction. So logic dictates that since wings move air down while also accelerating that same air, then the wing reacts with an opposing force in the opposite direction - AKA lift.
Stand under a helicopter, and feel the physics.
No one can demonstrate lift through the miracle of pressure differentials only - not without also thrusting air down. The pressure differentials are just what happens when air moves anywhere. They are a red herring, provided by 60 years of disinformation in our textbooks. The new and correct thinking is what I stated above.
And, if something's thrusting air down (hold onto your biggest plane with the props running full and feel the physics), then that something is reacting to it.
You cannot deny Newton.
Nawww - it's Newton.
Stand behind a prop, and feel the physics.
Newton states that for every action, there's a reaction. So logic dictates that since wings move air down while also accelerating that same air, then the wing reacts with an opposing force in the opposite direction - AKA lift.
Stand under a helicopter, and feel the physics.
No one can demonstrate lift through the miracle of pressure differentials only - not without also thrusting air down. The pressure differentials are just what happens when air moves anywhere. They are a red herring, provided by 60 years of disinformation in our textbooks. The new and correct thinking is what I stated above.
And, if something's thrusting air down (hold onto your biggest plane with the props running full and feel the physics), then that something is reacting to it.
You cannot deny Newton.
02-04-2012, 10:33 AM
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RE: Cambridge scientist debunks flying myth
The attached paper by Peter Lissaman tries to explain the origins of lift as simply as possible. It's lighthearted, but still a bit complex. This work is not at odds with the reference in the original post, but addresses the far more interesting case of "3D" lift
I think he makes a pretty convincing case for the idea that the rate at which a wing imparts net downward momentum to the air is zero.
link to the same file: http://www.redfish.com/friam/uploads...ningOfLift.pdf
I think he makes a pretty convincing case for the idea that the rate at which a wing imparts net downward momentum to the air is zero.
link to the same file: http://www.redfish.com/friam/uploads...ningOfLift.pdf
02-05-2012, 06:08 AM
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RE: Cambridge scientist debunks flying myth
ORIGINAL: Shoe
This is an apparently tidy explanation, but it neglects all the air that is being accelerated upward by a lifting wing (and to some extent a helicopter). Those who have gone through the rigor of summing up all of the momentum being imparted to the air (and to invoke Newton, you have to consider ALL the air being moved) have concluded that equality between the rate of momentum exchange and aerodynamic force does not exist. You cannot deny Newton, but you can misapply his laws.
ORIGINAL: Tim Green
Nawww - it's Newton.
Stand behind a prop, and feel the physics.
Newton states that for every action, there's a reaction. So logic dictates that since wings move air down while also accelerating that same air, then the wing reacts with an opposing force in the opposite direction - AKA lift.
Stand under a helicopter, and feel the physics.
No one can demonstrate lift through the miracle of pressure differentials only - not without also thrusting air down. The pressure differentials are just what happens when air moves anywhere. They are a red herring, provided by 60 years of disinformation in our textbooks. The new and correct thinking is what I stated above.
And, if something's thrusting air down (hold onto your biggest plane with the props running full and feel the physics), then that something is reacting to it.
You cannot deny Newton.
Nawww - it's Newton.
Stand behind a prop, and feel the physics.
Newton states that for every action, there's a reaction. So logic dictates that since wings move air down while also accelerating that same air, then the wing reacts with an opposing force in the opposite direction - AKA lift.
Stand under a helicopter, and feel the physics.
No one can demonstrate lift through the miracle of pressure differentials only - not without also thrusting air down. The pressure differentials are just what happens when air moves anywhere. They are a red herring, provided by 60 years of disinformation in our textbooks. The new and correct thinking is what I stated above.
And, if something's thrusting air down (hold onto your biggest plane with the props running full and feel the physics), then that something is reacting to it.
You cannot deny Newton.
Hold onto your baddest plane, at full throttle. Feel it try to pull away from you. Feel the prop (little rotating wings) blast against your skin (props move air backward, not both forward and backward). The plane pulling against your hands is reacting to the action of its own prop blast hitting your skin.
That's Newton. It's straightforward physics - and you can even feel it. You can touch it. And you can hold it in your hands. Nothing spooky. Action and reaction.
02-05-2012, 06:11 AM
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RE: Cambridge scientist debunks flying myth
ORIGINAL: Shoe
The attached paper by Peter Lissaman tries to explain the origins of lift as simply as possible. It's lighthearted, but still a bit complex. This work is not at odds with the reference in the original post, but addresses the far more interesting case of ''3D'' lift
I think he makes a pretty convincing case for the idea that the rate at which a wing imparts net downward momentum to the air is zero.
link to the same file: http://www.redfish.com/friam/uploads...ningOfLift.pdf
The attached paper by Peter Lissaman tries to explain the origins of lift as simply as possible. It's lighthearted, but still a bit complex. This work is not at odds with the reference in the original post, but addresses the far more interesting case of ''3D'' lift
I think he makes a pretty convincing case for the idea that the rate at which a wing imparts net downward momentum to the air is zero.
link to the same file: http://www.redfish.com/friam/uploads...ningOfLift.pdf
Poor guy - he's obviously not "feeling the physics".
02-05-2012, 06:40 AM
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RE: Cambridge scientist debunks flying myth
Not sure what "feeling the physics" buys you, but understanding the physics allowed him to design some pretty cool and successful aircraft, like this one...
http://en.wikipedia.org/wiki/Gossamer_Condor
http://en.wikipedia.org/wiki/Gossamer_Condor
02-05-2012, 07:36 AM
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RE: Cambridge scientist debunks flying myth
ORIGINAL: Shoe
Not sure what ''feeling the physics'' buys you, but understanding the physics allowed him to design some pretty cool and successful aircraft, like this one...
http://en.wikipedia.org/wiki/Gossamer_Condor
Not sure what ''feeling the physics'' buys you, but understanding the physics allowed him to design some pretty cool and successful aircraft, like this one...
http://en.wikipedia.org/wiki/Gossamer_Condor
Feel the Physics