the dreaded base to final turn

[Marauder]

Mathematically the Heisenberg uncertainty principle basically relates the errors in position and momentum to the Planck's constant: (ΔxΔp>h/2π)

It says that the error in position (x) multiplied by the error in momentum (p) is greater than Planck's constant, h.

Planck's constant is a very miniscule quantity, 6.626176 x 10⁻³⁴ joule-seconds. Because of this the H. uncertainty principle is unimportant to our large macroscopic world we're accustomed to. We can measure, for example, the position and velocity of a car or plane because the uncertainty as implied by the Heisenberg uncertainty principle is too small and insignificant. It is significant when we talk about the masses of atoms and subatomic particles.

The uncertainty of the position of a hit golf ball or baseball for example is in the order of 10⁻³⁰ mm. That's a miniscule fraction of a millimeter!

Quite right!

Heisenberg's uncertainty principle is the absolute limit of the measurability of physics quantities no matter how clean you try and make your experiment. Momentum and position simply do not both exist to ultra high precision beyond a certain point in a measurable sense do to quantum "blur".

That does not prevent you from making messier measurements in real life experiments. That is what the "observer effect" is about. As I said the classic example is you extract a small amount of air from a tire when measuring pressure thus changing the value of what you are measuring. This error is much much bigger than the scales suggested by Planck's constant. Try and make a smaller chamber in the pressure measuring device - sure - but we are not tickling Heisenber's uncertainty principle in these sorts of things - but they do struggle with that sort of scale in modern chip etching.

I love it when you guys talk dirty Physics; it brings the Einstein out of me

[aviatoreb]

I love it when you guys talk dirty Physics; it brings the Einstein out of me

 

Actually Einstein hated Quantum mechanics.  Some say that quantum mechanics was his undoing.  Although even in regard to Heisenberg's uncertainty principle, Einstein proved a major contribution in the process of trying to prove Quantum was all wrong: he proved the time energy uncertainty relation analogous to Heisenbergs position momentum relation.

 

Now back to topic - from this epic thread drift (my fault) - no one ever had a base to final accident because their airplane quantum-tunneled into a dangerous configuration.  It could happen but unlikely during the age of our universe.

The observer effect is not a quantum discussion Peter since it is simply a principle - yes analogous to Heisenberg's uncertainty principle, but not where near that tight precision.  It is a principle - that when you measure something, you disturb what you measure.  Pressure in a tire as I said, or to measure airspeed you stick a probe into the wind and thus slightly slow the airplane you are trying to measure its speed.  And this is an effect for much larger macroscopic values as compared to anything that Heisenberg's dead cat discusses - since our precisions are no where near the theoretical limits.

By the way, I got a beautiful small wooden box of Maple given to me over Christmas.  And my youngest son recently kicked out of his room the little stuffed cat he used to love when he was a little guy.  So I took that cat and put it in the box and put that in my office with a piece of tape on it labeled "Am I dead or alive - open and find out".  So far, my students who come by for office hours have not found it funny - I'm sort of disappointed.  You guys get it right?

[carusoam]

Reminds me of how difficult it is to measure EGT...

And how happy we are when we realize it is a relative measurement...

http://www.uh.edu/engines/epi347.htm

I had to look up the cat...

Erik,

You need to include the other trinkets in the box to have the students get and see humor in the whole thing???

Best regards,

-a-

[PTK]

It's Schrodinger's cat Erik!

Incidentally, one of my most favorite books is "What is Life?" By Erwin Schrodinger.

It's a little book in which, among other things, Schrodinger advances the idea of the structure of DNA as an aperiodic crystal. About 10 years later James Watson and Francis Crick, inspired by Schrodinger, go on and discover the structure of the double helix. They credit Schrodinger on his theories of the molecular storage of genetic material.

[scottfromiowa]

He says- "The first time I had any idea I was in trouble was when I hit the ground.  Up until that moment, all seemed fine."

I hope someone or better yet I decide to hang up my headset before I utter that statement.

 

[rq3]

Rip,

I appreciate your gentle, calm, knowledgable, helpful style.

Question: From your experience, when do pilots TAKE THEIR last look at the ASI or AOA on short final?

I noticed the other day while landing, it was further back then I expected. Once looking at the rwy numbers it becomes challenging to look out the side window, instruments and front window in a quick scanning format...

Wondering if you have some recommendations or knowledge of how other pilots use your instrument...

Best regards,

-a-

Many thanks. In my own flying in the pattern I glance at the color of the AoA during any turn. On short final I glance at the AoA to optimize the airspeed for the situation, and as a cross-check that I'm still safe.

Other folks really hang on the data, especially the folks flying bush in Huskys. I have one customer in Europe who, apparently, regularly makes landings in the mountains on 40 degree slopes at 12,000 feet. Why, I do not know, nor do I dare ask!

[aviatoreb]

It's Schrodinger's cat Erik!

 

Doh!  I know!!  Thanks.  But I mistyped as I was just thinking Heisenber and the started talking about the cat...  I would fix my post but its funnier to leave it wrong.

[Mooneymite]

(ΔxΔp>h/2π)

Have we been hacked by the Russians again?

[Hank]

Have we been hacked by the Russians again?

Yes, but those four threads are in the General Mooney section.

I glance at my ASI periodically throughout the pattern, including this turn and on final, and sometimes as I pull throttle to idle somewhere on short final.

[aviatoreb]

Have we been hacked by the Russians again?

No - hacked by quantum mechanics.

[schule]

Started a tailwheel checkout today. What a humbling experience to reinforce basic Airmanship skills.

Any effort less than a good crosscheck of the ASI, ball, and whole runway environment resulted in something not geting stablized.......If you have not experienced it, it can look a lot like one of those mechanical bulls.

An understanding of the pratical applications of AOA during idle power patterns to wheel landings made for lot more effective cross check and management of the Mooney pattern when I flew home.

This thread and a couple others combined with memories of lost friends has reinvograted the search for better GA flying skills.

[carusoam]

Siri tried to fix the mix-up...

I searched for Heisenberg's Cat and she delivered Schrodinger's Cat results without explaining the other guy didn't have a cat!

I have to check with my Dentist...

Need to see if this is normal for the dental community on weekends...

Quantum mechanix.

Leather interior mechanix.

Flies fast planes, probably does owner assisted MX with mechanics.

My daughter wants to be a dentist....

Best regards,

-a-

[kmyfm20s]

My daughter wants to be a dentist....

Best regards,

-a-

 

When I was in my Orthodontic residency my instructor told the group of us residents a story about how he was out golfing with a good friend of his which was a Pediatrician. I guess they where talking shop on the golf course and after they finished up the pediatrician told my instructor that he wished he was an Orthodontist. My instructor replied, I wish I was an Orthodontist wife:) I was single back then and thought that was funny. Im married now and realize how true that statement was.

[carusoam]

My orthodontist's wife ran his office... I think he was the employee?

That requires special people to do special team work!

Best regards,

-a-

[kmyfm20s]

My first wife was involved in the office, no bueno! 

[carusoam]

Some inapropriate fluff removed...

-a-

[DaV8or]

People. Cats are wonderful creatures. I have three in my home as I type. There are more cats than there are homes that want one. Screw philosophers and their theories. Go to the nearest shelter and get a cat needing a home. If you do this, the mysteries of the universe, physics and God will be revealed one face rub, one purr, one paddy cake at a time.

 

Do it now.

 

  From a crazy cat geezer that has rescued and placed over 20 cats/kittens and has had cats in my life since before I was born.

 

Oh yeah... base to final turn... Don't turn over 30 degrees, keep your speed up and get an AOA indicator. If you do bank more steeply, have the POH numbers ingrained in your head very recently and point the nose down. Basically, if you're going to fly by the numbers, really know the numbers.

[carusoam]

Dave,

Cats in the plane?

Ever?

-a-

[PTK]

Heisenberg and Schrödinger get pulled over for speeding.

The cop asks Heisenberg "Do you know how fast you were going?"

Heisenberg replies, "No, but we know exactly where we are!"

The officer looks at him confused and says "you were going 108 miles per hour!"

Heisenberg throws his arms up and cries, "Great! Now we're lost!"

The officer looks over the car and asks Schrödinger if the two men have anything in the trunk.

"A cat," Schrödinger replies.

The cop opens the trunk and yells "Hey! Do you know you have a dead cat in here?!"

Schrödinger angrily replies, "Well, we do now!"

[aviatoreb]

Heisenberg and Schrödinger get pulled over for speeding.

The cop asks Heisenberg "Do you know how fast you were going?"

Heisenberg replies, "No, but we know exactly where we are!"

The officer looks at him confused and says "you were going 108 miles per hour!"

Heisenberg throws his arms up and cries, "Great! Now we're lost!"

The officer looks over the car and asks Schrödinger if the two men have anything in the trunk.

"A cat," Schrödinger replies.

The cop opens the trunk and yells "Hey! Do you know you have a dead cat in here?!"

Schrödinger angrily replies, "Well, we do now!"

 

Badabump!  Ching! :-)

[scottfromiowa]

People. Cats are wonderful creatures. I have three in my home as I type. There are more cats than there are homes that want one. Screw philosophers and their theories. Go to the nearest shelter and get a cat needing a home. If you do this, the mysteries of the universe, physics and God will be revealed one face rub, one purr, one paddy cake at a time.

 

Do it now.

 

  From a crazy cat geezer that has rescued and placed over 20 cats/kittens and has had cats in my life since before I was born.

 

Oh yeah... base to final turn... Don't turn over 30 degrees, keep your speed up and get an AOA indicator. If you do bank more steeply, have the POH numbers ingrained in your head very recently and point the nose down. Basically, if you're going to fly by the numbers, really know the numbers.

O.K., Now I have got it.

[DaV8or]

Dave,

Cats in the plane?

Ever?

-a-

 

Nope. Only snakes.