Examples of Applied Physics

[Justin Adams]

I never really considered this. I though of the hydro-planes on a sub. Tilt up and up you go, provided there is sufficient speed so you do not stall. The 'laminar' wing shapes also seemed odd to me in comparison with the older airfoil designs. The lift to drag ratio as based on a varying angle of attack and the chord of the wing (the 'pivot' point of the weight and balance equations), was considered worth the extra wing surface. I think they did not necessarily hold to any one particular theory, but just the wind-tunnel designs that seem to work the best. I have experienced the flaps on a laminar wing in comparison to the more expensive to produce traditional airfoil. The laminar flaps point you down, may decrease the speed at which the wing stalls allowing for slower landing speed, but it always felt like a sort of controlled fall to me. The Fowler type flaps on the other hand, on the more traditional airfoils, increased lift and lowered the nose and allowed safer lower airspeed that seemed far more graceful to me.

In practical experience, the laminar wings seemed more reluctant to recover from a wing-root stall situation, so many of those earlier, laminar-flow airplanes were placarded against deliberate stalls and spins. The reason Piper designed their later trainers with high tail gear was to allow recovery from wing stalls and spins that certain turbulences created by stalls disallowed.

I also flew those balsa models long before I got into a cockpit. It still fascinates me to watch the gulls overhead.

[GandalfTheWise]

I just added a video showing the Coriolis effect on a merry-go-round.  It's a short (sub 30 seconds) that gives a nice demonstration of what I attempted to describe in words in the OP.  Here's the link to the approved video post.  

https://www.worthychristianforums.com/topic/212872-coriolis-effect-on-merry-go-round/

The key thing to understand about this is that the motion of the ball is quite real.  It is the observers' point of reference that determines how they will measure the ball's motion.  An observer standing to one side would measure a straight line and an observer sitting on the merry-go-round would measure a curve.

Over the years, many textbook descriptions of the Coriolis effect (and other rotational effects) have unfortunately used words such as "fictional" or "apparent" to attempt to describe the observed curved motion.  They were attempting to describe how the observer sitting on the merry-go-round could not observe a force acting on the ball to make it curve.  Indeed, to most people who sit on a merry-go-round and actually try this for the first time, it does sort of seem like magic when you try to throw a ball straight to someone and you watch it curve to one side.

On the earth's surface, the effect is quite small over the types of distances we are used to in everyday life.  Throwing a ball on a football field or a basketball court is dominated by air resistance and gravity which are so much larger that we never notice it in day-to-day life.  It is interesting to note that snipers and long distance shooters do account for the Coriolis effect for long range shooting.

 

[GandalfTheWise]

18 hours ago, Justin Adams said:

I never really considered this. I though of the hydro-planes on a sub. Tilt up and up you go, provided there is sufficient speed so you do not stall. The 'laminar' wing shapes also seemed odd to me in comparison with the older airfoil designs. The lift to drag ratio as based on a varying angle of attack and the chord of the wing (the 'pivot' point of the weight and balance equations), was considered worth the extra wing surface. I think they did not necessarily hold to any one particular theory, but just the wind-tunnel designs that seem to work the best. I have experienced the flaps on a laminar wing in comparison to the more expensive to produce traditional airfoil. The laminar flaps point you down, may decrease the speed at which the wing stalls allowing for slower landing speed, but it always felt like a sort of controlled fall to me. The Fowler type flaps on the other hand, on the more traditional airfoils, increased lift and lowered the nose and allowed safer lower airspeed that seemed far more graceful to me.

In practical experience, the laminar wings seemed more reluctant to recover from a wing-root stall situation, so many of those earlier, laminar-flow airplanes were placarded against deliberate stalls and spins. The reason Piper designed their later trainers with high tail gear was to allow recovery from wing stalls and spins that certain turbulences created by stalls disallowed.

I also flew those balsa models long before I got into a cockpit. It still fascinates me to watch the gulls overhead.

That is interesting.   Fluid flow is very complicated especially when it is a compressible fluid like air.  I have the feeling that there is the actual physical shape of the wing and then there is the "effective" shape of the wing (which varies with speed, angle, etc.)  which includes a boundary layer of vortices and "stable" air patterns near the wing.  My gut feeling is that the actual air flow patterns that do the pushing and lifting are interacting with the "effective" shape of the wing rather than the physical shape of the wing.  

Last Christmas, my mother got me the book about the Wright Brothers by David McCullough.  It was a fascinating book.  I had always thought of them as some tinkerers that were lucky enough not to get killed.  They actually did a lot of high level applied engineering in order to figure out how to fly.  I had no idea that they made their own wind tunnel, did many mock ups, did lots of testing, and then realized that one of the main keys to flying was the pilot having enough practice to do it right.  This was a well document book that followed their family life, travels to Kitty Hawk and around the world, their engineering progress.  I found it very interesting.

[Justin Adams]

Very interesting.

The idea of warping the wing slightly is cool too (in order to maneuver). I watch gulls and kites, it is amazing how they can read the currents and adapt by warping their wings. I often think that God must love to fly. You see, in an imagined world with no birds or flying critters of any kind, I wonder if man would have ever thought of its possibility.

Edited September 25, 2017 by Justin Adams
typo

[Enoch2021]

7 hours ago, GandalfTheWise said:

I just added a video showing the Coriolis effect on a merry-go-round.  It's a short (sub 30 seconds) that gives a nice demonstration of what I attempted to describe in words in the OP.  Here's the link to the approved video post.  

https://www.worthychristianforums.com/topic/212872-coriolis-effect-on-merry-go-round/

Thanks for the 2nd Grade demonstration. 

The Coriolis Effect most certainly exists... with respect to a Rotating Body.

You do realize that the Coriolis Effect EXISTING (the "Apparent" Deflection of an object)/Tenets of it's Existence, is the entire foundation of my argument.   

 

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The key thing to understand about this is that the motion of the ball is quite real.

For a person observing from the Inertial frame of reference (i.e., Non-Rotating) the ball travels in a Straight Path; however anyone who is attached to/in the Non-Inertial frame of reference, the ball Deflects ... this is an APPARENT Deflection (See above: Straight Path) Ergo...it's NOT REAL.

 

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Over the years, many textbook descriptions of the Coriolis effect (and other rotational effects) have unfortunately used words such as "fictional" or "apparent" to attempt to describe the observed curved motion.

Unfortunately  ??  They use it because that's what it is...

 

"CC.12 The Coriolis Effect:

When set in motion, freely moving objects, including AIR [Atmosphere] and WATER masses [Clouds/Water Vapor], move in straight paths while the Earth continues to 

                                                 ROTATE INDEPENDENTLY.

Because freely moving objects ARE NOT carried with the Earth as it Rotates, they are subject to an APPARENT DEFLECTION called the “Coriolis effect.” To an observer rotating with the Earth, freely moving objects that travel in a straight line APPEAR to travel in a curved path on the Earth."
Segar, Douglas A; Introduction to Ocean Sciences, 2nd Edition: Critical Concept Reminders -- CC.12 The Coriolis Effect (pp. 313, 314, 323, 324), 
ISBN: 978-0-393-92629-3, 2007.
http://www.wwnorton.com/college/geo/oceansci/cc/cc12.html

 

"The effect of the Coriolis force is an APPARENT DEFLECTION of the path of an object that moves within a rotating coordinate system. The object DOES NOT actually deviate from its path, but it APPEARS to do so because of the motion of the coordinate system."
http://abyss.uoregon.edu/~js/glossary/coriolis_effect.html

"Within its rotating coordinate system, the object acted on by the Coriolis effect APPEARS TO DEFLECT off of its path of motion. This deflection is not real. It only APPEARS to happen because the coordinate system that establishes a frame of reference for the observer is also rotating...
The Coriolis effect (sometimes called the Coriolis force) is the APPARENT DEFLECTION of air masses and fluids caused by Earth's rotation . Named after the French mathematician Gustave-Gaspard Coriolis, (1792-1843), who developed the concept in 1835, the Coriolis force is a PSEUDO-FORCE (FALSE FORCE) and should properly be termed the Coriolis effect."
http://www.encyclopedia.com/earth-and-environment/atmosphere-and-weather/weather-and-climate-terms-and-concepts/coriolis-effect

 

Coriolis Force --A PSEUDO FORCE used mathematically to describe motion, as of aircraft or cloud formations, relative to a noninertial, uniformly rotating frame of reference such as the earth."
http://www.thefreedictionary.com/Coriolis+force

 

"The Coriolis force is not the only FICTITIOUS FORCE that acts on the ball from the point of view of an observer sitting on the rotating merry-go-round." 
http://www.real-world-physics-problems.com/coriolis-force.html

 

"An elegant example of these types of apparent influences is the FICTITIOUS Coriolis force..."
What is a "FICTICIOUS FORCE"?
https://www.scientificamerican.com/article/what-is-a-fictitious-force/

 

How many more do ya need?

 

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On the earth's surface, the effect is quite small over the types of distances we are used to in everyday life.

Factually Incorrect, they should be quite noticeable...just like they're quite noticeable on the merry-go-round.

 

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Throwing a ball on a football field or a basketball court is dominated by air resistance and gravity which are so much larger that we never notice it in day-to-day life.

Not according to Neil "Smokin de-grass" Tyson (You Tube): 'Neil deGrasse Tyson explains Coriolis effect on field goal kick'.

ps. 'gravity'  is a Fairytale.

 

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It is interesting to note that snipers and long distance shooters do account for the Coriolis effect for long range shooting.

Really?

I'm retired Army, half my career spent in Combat Arms (Reconnaissance)... Expert Infantryman .  I cross-trained with Snipers nearly every quarter (besides being drinking buddies)... they were right down the hall.

I never even heard the Term "Coriolis Effect" much less ACTUALIZED IT !!!
I've personally made shots between 1100 and 1500 Meters without taking into account some Fairytale Coriolis Effect.

MOREOVER, a Globe Earther tried to float the same 'Story' as you and got PUMMELED by a Tank Master Gunner, here (You Tube): Flat Earth vs Globe Earth Debate. (Time 34:35)

 

regards

[GandalfTheWise]

Calculating the Coriolis acceleration for various situations is straightforward.  It's magnitude is 2 ω v  where ω is angular speed of the rotating reference frame and v is the speed of the moving object perpendicular to the rotation in the plane of rotation.   On the surface of a sphere, v has to take into consideration the latitude of its location.  At 45 degrees latitude, v must be multiplied by Sin[45 degrees] which is the same as dividing by the square root of 2. 

Assuming a merry-go-round rotates once every 5 seconds, ω is 10 Pi radians/sec.  For a ball thrown or rolled at 2 ft/sec toward the center of the merry-go-round, the Coriolis acceleration will be about 5 ft/sec^2.  This is large enough to be noticeable as could be seen on the video.

Assuming a football is kicked 60 yards (in Lambeau field near 45 degrees N) and is in the air for 3 seconds, ω is 2 Pi radians/day, and v is 20/Sqrt[2] yards/sec.  This gives a Coriolis acceleration of about 0.002 yards/sec^2.  This corresponds to a drift of less than an inch.  This is essentially undetectable.  (Strictly speaking, this example should consider the entire arc of the ball relative to the perpendicular direction to motion.  However, that won't change the result much because the ball will see more Coriolis effect on its upward curve and less Coriolis effect on its downward curve.)

Assuming a bullet is traveling at 2000 ft/sec (somewhere near either 45 Degrees N or S), ω is 2 Pi radians/day, and v is 2000/Sqrt[2]  ft/sec.  This gives a Coriolis acceleration of about 0.2 ft/sec^2.  This corresponds to a drift of an inch or so for about 4 seconds of flight time.   The faster the bullet speed or the longer the distance, the larger the deflection.

I have no personal experience with long distance shooting so I looked for sources that appeared to have some credibility.

I took my information about long distance shooting from the Applied Ballistics web site.  Here's an article about them at the King of 2 Miles shooting competition.  https://www.ssusa.org/articles/2017/1/9/king-of-2-miles-extreme-long-range-competition/  Their goal is 2 mile hits on the first round of competition.  I'm not sure, but I take that to mean on the first shot.  Articles on their web page indicate that they account for the Coriolis effect for long ranges.  http://www.appliedballisticsllc.com/Articles/ABDOC108_GyroscopicAndCoriolis.pdf  This site has a number of interesting articles about factors they consider for improving their long distance shooting capability.

I also took this from a Navy Seal's accounts of sniper school where he mentions accounting for it for extreme distances.  https://navyseals.com/4781/inside-the-seal-teams-navy-seal-sniper-school-part-2/

 

3 hours ago, Enoch2021 said:

I'm retired Army, half my career spent in Combat Arms (Reconnaissance)... Expert Infantryman .  I cross-trained with Snipers nearly every quarter (besides being drinking buddies)... they were right down the hall.

I do appreciate your military service.  I have a cousin that went to West Point and retired as a Lt Col,  a nephew (with some physical disability now) that did 3 tours in Iraq and then spent a few years doing something with communication equipment at Ft. Benning with the Rangers, and my Dad (when in HS) lost his brother in the AF in a peace time crash.   I do respect what it takes to spend part or all of a career in the military.

I see you're in MO.  My wife and I did a spur of the moment road trip down to Columbia to see totality of the eclipse.  It was stunning.  Did you get to see totality?

 

[Enoch2021]

10 minutes ago, GandalfTheWise said:

Calculating the Coriolis acceleration for various situations is straightforward.  It's magnitude is 2 ω v  where ω is angular speed of the rotating reference frame and v is the speed of the moving object perpendicular to the rotation in the plane of rotation.   On the surface of a sphere, v has to take into consideration the latitude of its location.  At 45 degrees latitude, v must be multiplied by Sin[45 degrees] which is the same as dividing by the square root of 2. 

Assuming a merry-go-round rotates once every 5 seconds, ω is 10 Pi radians/sec.  For a ball thrown or rolled at 2 ft/sec toward the center of the merry-go-round, the Coriolis acceleration will be about 5 ft/sec^2.  This is large enough to be noticeable as could be seen on the video.

The Coriolis Effect certainly exists in a 'merry-go-round' scenario, since it's rotating. However...

There is No Coriolis Effect with Respect to the Earth, I Falsified that Earlier.  (SEE: Charlotte to LA Flight "Time" example)

 

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Assuming a football is kicked 60 yards (in Lambeau field near 45 degrees N) and is in the air for 3 seconds, ω is 2 Pi radians/day, and v is 20/Sqrt[2] yards/sec.  This gives a Coriolis acceleration of about 0.002 yards/sec^2.  This corresponds to a drift of less than an inch.  This is essentially undetectable.  (Strictly speaking, this example should consider the entire arc of the ball relative to the perpendicular direction to motion.  However, that won't change the result much because the ball will see more Coriolis effect on its upward curve and less Coriolis effect on its downward curve.)

You don't notice it because it Doesn't EXIST.  

 

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Assuming a bullet is traveling at 2000 ft/sec (somewhere near either 45 Degrees N or S), ω is 2 Pi radians/day, and v is 2000/Sqrt[2]  ft/sec.  This gives a Coriolis acceleration of about 0.2 ft/sec^2.  This corresponds to a drift of an inch or so for about 4 seconds of flight time.   The faster the bullet speed or the longer the distance, the larger the deflection.

It's a Fairytale.

 

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I have no personal experience with long distance shooting so I looked for sources that appeared to have some credibility.

You don't need a Source... I'm the Source (and the Brigade Level Tank/Fire Control Officer reference I provided)

 

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I took my information about long distance shooting from the Applied Ballistics web site.  Here's an article about them at the King of 2 Miles shooting competition. https://www.ssusa.org/articles/2017/1/9/king-of-2-miles-extreme-long-range-competition/ Their goal is 2 mile hits on the first round of competition.  I'm not sure, but I take that to mean on the first shot.  Articles on their web page indicate that they account for the Coriolis effect for long ranges. http://www.appliedballisticsllc.com/Articles/ABDOC108_GyroscopicAndCoriolis.pdf This site has a number of interesting articles about factors they consider for improving their long distance shooting capability.

Baloney!

 

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I also took this from a Navy Seal's accounts of sniper school where he mentions accounting for it for extreme distances. https://navyseals.com/4781/inside-the-seal-teams-navy-seal-sniper-school-part-2/

I don't care if they resurrected Audie Murphy and he swore an Oath to the Coriolis Effect.  It's Horse Pucky.

 

 

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I do appreciate your military service.

You're Welcome.

 

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 I have a cousin that went to West Point and retired as a Lt Col,  a nephew (with some physical disability now) that did 3 tours in Iraq and then spent a few years doing something with communication equipment at Ft. Benning with the Rangers,

Well we chewed some of the same ground.  

 

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I see you're in MO.  

Yep.  The "SHOW ME" State. 

 

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My wife and I did a spur of the moment road trip down to Columbia to see totality of the eclipse.  It was stunning.  Did you get to see totality?

Yep.  70 Miles Wide  Speaking of which...

According to the Heliocentric (Sun Worshiping) Spinning-Ball Religion, the sun is 93 million miles away (smh); Therefore by definition, all Light Rays from the Sun that contact the Earth MUST BE "PARALLEL".
 

1.  So according to 'The Narrative' (aka: Fairytale) we have the 'purported' Penumbra (Caused by 'Convergent' Sun Rays) vs Eratosthenes ('Parallel' Sun Rays).
We have people Stage 5 Cling with a Kung Fu Death Grip to Eratosthenes Trainwreck (Which btw, was Independently Falsified unwittingly by Cleomedes six ways from Sunday and common sense) yet at the same time Mindlessly PARROT "B' gAAK... Penumbra !!"??

See the Contradiction?  

Listen Closely, Every Photon that hits the Earth/Moon MUST -- by simple geometry and definition, be traveling at a Dead 90.00000000000000000000 degrees from ANY point on the surface of the Sun to it's straight line sister location on either the Earth/Moon.
If a Photon is fired at </> 90.00000000000000000000 degrees from any point on the surface of the SUN to it's straight line sister location on the Earth/Moon from 93 MILLION MILES AWAY...then it will MISS the Earth/Moon by Hundreds of Thousands to Million of MILES!

Ya Follow? 

They ('Convergent' Sun Rays vs 'Parallel' Sun Rays) are "Mutually Exclusive".

Which is it Spinning-Globe Adherent's?  Pick One...?? (Choose Wisely )  

Then...

2.  How can a Total Solar Eclipses Path of Totality Shadow... ~30 TIMES SMALLER than the MOON'S DIAMETER ???

There's NO POSSIBLE way an object can project a Shadow "SMALLER" than it's own Diameter !! It's Kooky Talk.  

 

3.  Moreover, if with a Total Solar Eclipse Path of Totality Shadow is 70 Miles Wide...THEN...with Lunar Eclipses, the Shadow of the Earth on the Moon should be... 256 MILES IN DIAMETER !!!  Ahhh...

 

regards

[GandalfTheWise]

On 9/25/2017 at 6:35 PM, Enoch2021 said:

There's NO POSSIBLE way an object can project a Shadow "SMALLER" than it's own Diameter !! It's Kooky Talk.  

 Here's a simple experiment that can be done with a laptop or computer monitor, a piece of white lined paper, and a quarter.

1. Turn off the lights in the room to make it as dark as possible.  That makes it easier to see the light and shadows on the paper.

2. Open a blank word processing page with a white background, expand it to fill the screen, and turn up the monitor brightness.  This gives a nice extended white light source.

3. Hold the paper about a foot away from the laptop screen so that the paper and screen are parallel.

4. Start with the quarter a couple inches from the paper and slowly move it toward the paper.  It will cast a circular shadow (ignoring the shadows from fingers holding it).

Distinct solid and partial shadows will appear.  They of course vary in size as the quarter is moved closer or further from the paper.  The key thing to observe is that the solid shadow can be made smaller than the diameter of the quarter at the right range of distances.  The partial shadow is of course  larger than the diameter of the quarter.  But the size of the solid shadow (or "totality") can be made smaller than the diameter of the quarter.

[Enoch2021]

1 hour ago, GandalfTheWise said:

 Here's a simple experiment that can be done with a laptop or computer monitor, a piece of white lined paper, and a quarter.

1.  Why 'reinvent the wheel' with your False Equivalence Fallacy 'experiment', when the University of Minnesota already showed it ("as if" we actually needed it)...

So again, How can you have a shadow projected from an object that's ~30 Times Smaller than the ACTUAL Object??

2.  Why do we need your contrived False Equivalence Fallacy Experiment when we have High Altitude Balloon Footage of the Actual Eclipse showing NO Penumbra, (You Tube): Flat Earth Eclipse - Rahu or Luna? Special Balloon Redemption Edition! (Start at 3:09:00) At 3:11:40... "Notice here and on all the other footage NO PENUMBRA".

 

ps. Do you finally realize that according to the tenets of the Coriolis Effect, the notion that the Earth is 'Spinning' is a Fairytale of Epic Proportions?

And if that's the case (and it most assuredly is ), then Alice in Wonderland is more tenable than the Spinning-Ball Religion.

 

regards

[GandalfTheWise]

This set of schematics should illustrate more clearly the various types of shadows and their sizes for different types and sizes of light sources.  The first column is a schematic of the physical geometry.  The second column illustrates the light and shadow that is projected on the screen behind the object.

A light source that focuses parallel rays of light will project a shadow on a screen that is the same size as the object.  A point light source (which is a good approximation for a small light source or one far away) will project a shadow larger than the object.

A distributed light source (such as a fire or a computer monitor) emits light in different directions from each part of the source.  You can treat a distributed light source as a collection of point sources.  The result is a beam of light in which the rays are not uniformly parallel and are being emitted from across the surface of the source.  When a distributed light source is larger than the target, it can project a more complicated shadow pattern that includes an umbra (complete shadow) and a penumbra (partial shadow).

The bottom two rows are the same situation.  The bottom one just shows some of the light rays to give an idea of how the light beam is filled with rays being emitted from different parts of the source.