Will someone settle up on a bet?

[old man emu]

On 10th March , APenNameAndThatA  at https://www.recreationalflying.com/topic/37167-turns-at-low-ias/page/15/ made two bets:

 

I’ll give you $500 if you can demonstrate that something with a mass of 0.3 kg has a weight of 3 kg. Same thing with the AOA meter. If it works, you get the cash. 

 

Let's take the first one.

The reference I am giving you uses a mass of one kilogram in its calculation, but the same holds true for a mass of three kilograms. Also the calculation uses 9.8 m/s/s as the value of the acceleration due to gravity. It was agreed that for smplicity, that value could be rounded to 10 m/s/s

 

https://www.topperlearning.com/answer/what-is-one-kg-wt-how-many-newtons-makes-1-kg-wt/ez2t3ii

 

Now, having had someone else, whom I do not know, say exactly what I said, quod erat demonstrandum.

 

The second one - The simple bubble spirit level AoA indicator.

If one is prepared to accept the word of of Mr John Munn Chief Engineer (and Collection pilot) of the Shuttleworth Collection, then, in his words,  "it could also be used give an indication of the AOA but that is of very little practical purpose," and  "you could derive AoA but in each case it would only be for a given set of parameters".   https://www.recreationalflying.com/topic/37345-regarding-angle-of-attack-indicators/?tab=comments#comment-504199

 

I never said that a simple bubble spirit level would be the ultimate answer to the problem of indicating the proximity of the chord line to the stall angle. I said that it could be used to give an indication. Consider  a simple "stick on a float" fuel quantity indicator. They work well if the fuel tank is basically a rectangular prism, and the stick is visible to the pilot, but just about as useless as tits on a bull if the fuel tanks is in the wing of a high wing aircraft.  As Facthunter reminded us,  if you are going in the wrong direction you have to get back to where you started before you get anywhere. 

 

 

In the early years many patents were granted for devices to give the pilot an indication of the orientation of the aircraft. Some were simple liquid filled tubes and otheres more sophisticated pendulum designs like this one: https://patentimages.storage.googleapis.com/aa/f4/be/2a4f497f677243/US1308795.pdf of which the inventor says: 

My present invention relates to improvements in inclinometers for use on aircraft. With such craft it is desirable at all times to know the angle or inclination of both the longitudinal and transverse axes, (my emphasis -OME) and this is especially difficult when the aircraft is in the clouds, or above the clouds, or at night. . . . . According to my invention I provide a simple, cheap and effective device for this purpose, which is not likely to get out of order, and yet which may be quickly and conveniently read by the aviator when desired. 

 

Once again, having had someone else, whom I do not know, say exactly what I said, quod erat demonstrandum. There you have it. If it works, you get the cash. It works. It works poorly. When it works it is not very practical, but it works.

 

That's two bets of $500 each. I'm sure that $500 each for Reacreationalflying.com and socialaustralia.com.au would be well received.

[Marty_d]

50 minutes ago, old man emu said:

I’ll give you $500 if you can demonstrate that something with a mass of 0.3 kg has a weight of 3 kg. Same thing with the AOA meter. If it works, you get the cash. 

Mass remains the same, weight is an effect on mass by gravity.

 

Simple to change, if you apply a force of 10G to something with a mass of 0.3kg it will weigh 3kg.  If you want it demonstrated, put a 0.3kg weight in a centrifuge on a scale (at the outside) which reads out somewhere visible.  As the centrifuge spins up your scale will show the increasing weight until it's 3kg.

 

Postal money order or bank transfer will be fine.

[old man emu]

1 hour ago, Marty_d said:

Mass remains the same, weight is an effect on mass by gravity.

Marty, you should have stopped there, where you are correct. 

 

Please don't confuse the matter by bringing in centripetal force. What you said in relation to you experiment is correct, but a lot of people here will want to wander off down a path we don't want to traverse.  You could have used the values for the other planets to make your point.

Calculating g on Other Planets

 The value of g on any other planet can be calculated from the mass of the planet and the radius of the planet. The equation takes the following form:

http://www.physicsclassroom.com/Class/circles/u6l3e6.gif where G = Universal Gravitational Constant = 6.674×10⁻¹¹ m³⋅kg⁻¹ 

Using this equation, the following acceleration of gravity values can be calculated for the various planets.

Planet	Radius (m)	Mass (kg)	g (m/s2)
Mercury	2.43 x 106	3.2 x 1023	3.61
Venus	6.073 x 106	4.88 x1024	8.83
Mars	3.38 x 106	6.42 x 1023	3.75
Jupiter	6.98 x 107	1.901 x 1027	26.0
Saturn	5.82 x 107	5.68 x 1026	11.2
Uranus	2.35 x 107	8.68 x 1025	10.5
Neptune	2.27 x 107	1.03 x 1026	13.3
Pluto	1.15 x 106	1.2 x 1022	0.61

   

That should bring the wanderers to heel.

[aro]

Someone might have been looking for a higher level of proof than OME declaring himself correct.

 

I think you have misunderstood what Mr Munn wrote - selectively picking out bits that support you. From your post of his reply:

 

Quote

It can’t tell AoA either- it has no way of knowing where the relative wind is coming from.

Quote

you could derive AoA but in each case it would only be for a given set of parameters

 

We can and do derive AOA much more accurately and reliably from the airspeed indicator. A stopped clock is also correct for a given set of parameters, but like the spirit level AOA you need enough additional references to know when that is that the original reading becomes redundant.

 

Quote

in steady/unaccelerated flight, at a given speed airspeed the instrument can be set at the right angle to give the pilot an indication of whether he is flying level or at a descending or climbing attitude

 

That is correct. It displays attitude not AOA, but only in one axis and only in unaccelerated flight. The attitude indicator shows the same and more information more reliably e.g. it isn't affected by acceleration.

[aro]

13 minutes ago, old man emu said:

The value of g on any other planet

Rather than bringing other planets into it, maybe you should re-read what you wrote. You made a simple unit conversion error - switching from kg to newtons without a conversion.
 

Quote

 

If we determine the "weight" of the object, to be 3 kg,

If we now put on our lab coats and become scientists, we will start talking in terms of Newtons. The scale shows us that the object exerts a force of 3 Newtons on the weighing mechanism.  Therefore in the equation F=ma, it is F that equals 3. We agree that a is an acceleration of 9.81 metres per second every second. If, for simplicity's sake, we round 9.81 to 10, then 3 = m.10. Therefore m = 3/10 which is 0.3.

 

 

3 newtons should have been 30 newtons, rounding 9.81 to 10.

 

[old man emu]

First.

You made me present my credentials. How about you doing the same?

 

Second.

You and your mate are so keen on precision. He said "If it works, you get the cash." It works. It works poorly. When it works it is not very practical, but it works. 

 

Third.

It is not very practical. But consider this: early aircraft builders tended to be general practitioners. They made use of their experience in other fields to improve the performance of their planes. This often resulted in a bit of "outside the box" thinking whereby they took an existing idea and adapted it to do a job in the aircraft. Think of the "stick on a float" fuel gauge as one of these applications. As it became obvious that the problem wasn't being solved by these simple devices, experts from other fields took up the challenge.

 

One of these non-aviation experts was Elmer Ambrose Sperry Sr. (October 12, 1860 – June 16, 1930), an American inventor and entrepreneur, most famous for construction of the gyrocompass and as founder of the Sperry Gyroscope Company. He may have been brought to the periphery of aviation by his son, Lawrence Burst Sperry (21 December 1892, Chicago, Illinois, United States – December 13, 1923, English Channel) was an aviation pioneer. In 1917, Sperry solved the issue of magnetic compasses indicating the opposite position when an aircraft is turning, inventing the Gyro Turn Indicator. This turn indicator was later modified into what is known now as the Turn and Slip Indicator. With a Directional Gyro and Gyro Horizon added later, Sperry created a core of flight instruments that became standard equipment on all aircraft

 

Few can deny that gyroscopically operated devices are a lot better, but even they suffer from the inability to detect the direction of airflow in relation to the chord.

 

[old man emu]

5 minutes ago, aro said:

You made a simple unit conversion error - switching from kg to newtons without a conversion.

So, instead of simply identifying a simple arithmetic error you launch into statements like this "Someone might have been looking for a higher level of proof than OME declaring himself correct."  Rather discourteous.

 

[aro]

27 minutes ago, old man emu said:

So, instead of simply identifying a simple arithmetic error

APenNameAndThatA pointed it out and how many posts did you spend arguing? I knew what you meant and it didn't seem worth worrying about.

[aro]

41 minutes ago, old man emu said:

It works. It works poorly.

An AOA indicator that according to the expert you quote "can’t tell AoA" doesn't work.

 

[facthunter]

A length of wool is an AoA indicator if it's in free air and suitably  mounted. It's no big deal. Having an AoA reference takes the guesswork out of being close. You don't fly looking at it constantly  nor do you with an ASI.  You fly attitudes, constantly correcting them as needed.  The early  reference to blind flying was Attitude Instrument Flying the "Artificial Horizon " replacing the visual horizon. .  Nev

[Marty_d]

6 hours ago, old man emu said:

Marty, you should have stopped there, where you are correct. 

 

Actually I think the entire post was correct.  

Plus I thought it was easier keeping things here on Earth rather than sticking them in Uranus...

[440032]

63 Earths will fit inside Uranus. (64 if you hold your breath.)

[old man emu]

15 hours ago, Marty_d said:

Actually I think the entire post was correct.

Definitely. But you know what happens to these threads if you present a fork in the road.

 

Also it is only a relatively new bit of knowledge, since we started putting satellites into orbit that we found that the strength of the Earth's gravitational force varies from place to place. Makes it easier to talk about weight if you use the Moon and planets as references.

 

aro, did you bother to look at this link?

 

On 27/03/2021 at 9:33 AM, old man emu said:

 

https://www.topperlearning.com/answer/what-is-one-kg-wt-how-many-newtons-makes-1-kg-wt/ez2t3ii

 

[lee-wave]

You come across two identical objects in deep space.  One is filled with duck feathers the other is full of Osmium (twice the weight of lead).  How would you determine which one was the feather filled object and vice versa without touching it ?  in other words which object had the greater mass ?

[old man emu]

9 hours ago, lee-wave said:

in other words which object had the greater mass

That is another way of putting, "Which would you rather have dropped on you, a tonne of feathers or a tonne of bricks?".

 

Two identical objects filled with stuff. Let's consider the objects to be 40 foot shipping containers. The density of osmium is 22610 kg/m3. If the containers are in deep space, we can fairly assume that there is no air between individual feathers, so it is fair to say that we could compress the feathers closer together than we could on Earth. However, it is unlikely that we could compress them to the same density as osmium, so the density of the feathers would be less and so the mass would be, too.

 

It could be done by the use of Newton's law of universal gravitation, which says 

the attractive force (F) between two point-like bodies is directly proportional to the product of their masses (m₁ and m₂) and inversely proportional to the square of the distance, r, between them:

 

But since you don't have values for the masses, you have to try something experimental. If you could fix one container in place (the reference container) and bring the other (the target container) within a known distance (r), then you could see which container moved towards the other. If the target container does not move, then you would know that the reference container's gravitational force on the target container was not sufficient to overcome the target container's inertia and move it. Therefore the reference container has the feathers and the target one the osmium. If the target container was the one that moved, then it is the one with the feathers.

[Peter Piper]

I'm late to this soiree , but that might actually allow me to assist you better. Allow me to state my credentials, fellow aviators: I graduated in the top 1% of highschool students, and studied a little physics at university and a little maths as a post graduate. I carefully read the thread that the administrator closed. It seems to me that it is important to Mr Emu to discuss this but, like most of us, he is distressed by not being listened to when he has gone to so much trouble. Mr Pen was rude and stated his case without listening to Mr Emu. I might also add that I was a member of the Philosophy Club at university and like precise language.

 

Wikipedia states the following about socratic questioning.

 

Socratic questioning (or Socratic maieutics)^[1] was named after Socrates. He utilized an educational method that focused on discovering answers by asking questions from his students. According to Plato, who was one of his students, Socrates believed that "the disciplined practice of thoughtful questioning enables the scholar/student to examine ideas and be able to determine the validity of those ideas".^[2] Plato described this rigorous method of teaching to explain that the teacher assumes an ignorant mindset in order to compel the student to assume the highest level of knowledge.^[3] Thus, a student has the ability to acknowledge contradictions, recreate inaccurate or unfinished ideas and critically determine necessary thought.

 

Wikidedia states the following about thought experiments.

 

A thought experiment is a hypothetical situation in which a hypothesis, theory,^[1] or principle is laid out for the purpose of thinking through its consequences.

Johann Witt-Hansen established that Hans Christian Ørsted was the first to use the German term Gedankenexperiment (lit. thought experiment) circa 1812.^[2] Ørsted was also the first to use the equivalent term Gedankenversuch in 1820.

Much later, Ernst Mach used the term Gedankenexperiment in a different way, to denote exclusively the imaginary conduct of a real experiment that would be subsequently performed as a real physical experiment by his students.^[3] Physical and mental experimentation could then be contrasted: Mach asked his students to provide him with explanations whenever the results from their subsequent, real, physical experiment differed from those of their prior, imaginary experiment.

The English term thought experiment was coined (as a calque) from Mach's Gedankenexperiment, and it first appeared in the 1897 English translation of one of Mach's papers.^[4] Prior to its emergence, the activity of posing hypothetical questions that employed subjunctive reasoning had existed for a very long time (for both scientists and philosophers). However, people had no way of categorizing it or speaking about it. This helps to explain the extremely wide and diverse range of the application of the term "thought experiment" once it had been introduced into English.

The common goal of a thought experiment is to explore the potential consequences of the principle in question:

"A thought experiment is a device with which one performs an intentional, structured process of intellectual deliberation in order to speculate, within a specifiable problem domain, about potential consequents (or antecedents) for a designated antecedent (or consequent)" (Yeates, 2004, p. 150).

I propose that Mr Emu subject his ideas to socratic questioning about a thought experiment about the measurement of mass. When Mr Pen returns to the forum, his ideas can be subjected to similar examination. If Mr Emu agrees to this course of action, then I, playing the part of Socrates, will ask him a series of questions. Mr Emu must agree to specifially answer them, in the manner set out by the ancient Greeks. I invite Mr Emu to submit to this careful, polite questiong. If he wishes, he can wait for Mr Penn to return to the forum and they can discuss to their heart's content. What say you, Mr Emu? All eyes will be on your good self! I would also request that other parties avoid interrupting the conversation, if you please!

[Jabiru7252]

Place a pin head equal distance between each object. The one with the greater mass will attract the pin head to itself having more gravity than the object of less mass. Do I get a star stamp on my hand?

[old man emu]

15 hours ago, Peter Piper said:

What say you, Mr Emu

First, Peter, it's Old Man Emu or OME, but thanks for the polite appellation.

 

Secondly, thanks for taking the time to research and post the above response. It is most interesting.

 

Thirdly, it is the nature of this forum for people to add their two cents' worth. It is the nature of forums, and, although a noble thought, is not democratic.

 

Fourth, the thread was closed at my request.

 

Fifth, based on a long history, of similar attacks on what I have said by a certain party, to open another thread to do as you suggest would be an "Open, Sesame" for further attacks.

 

Sixth, other people have had enough of this topic. In my opinion it is because the difference between the scientist's "mass" and the layman's "mass" has not been understood. And when I throw in terms like Avogadro's Number, Planck's Constant and mention the current definition of the kilogram, the level of misunderstanding rises exponentially.

 

Seventh, you have hinted at your academic qualifications, and I, too, have qualifications in science at the baccalaureate level, as well as internationally recognised qualifications in the application of Newton's Laws to daily occurrences. However, no one else has disclosed their training and experience in this field when attempting to rebut what I have said.

 

Therefore, I reluctantly decline your offer. I regret that I have to do that, as it sounds like a really interesting process.

 

With thanks, 

Old Man Emu

 

[Peter Piper]

4 hours ago, old man emu said:

First, Peter, it's Old Man Emu or OME, but thanks for the polite appellation.

 

Secondly, thanks for taking the time to research and post the above response. It is most interesting.

 

Thirdly, it is the nature of this forum for people to add their two cents' worth. It is the nature of forums, and, although a noble thought, is not democratic.

 

Fourth, the thread was closed at my request.

 

Fifth, based on a long history, of similar attacks on what I have said by a certain party, to open another thread to do as you suggest would be an "Open, Sesame" for further attacks.

 

Sixth, other people have had enough of this topic. In my opinion it is because the difference between the scientist's "mass" and the layman's "mass" has not been understood. And when I throw in terms like Avogadro's Number, Planck's Constant and mention the current definition of the kilogram, the level of misunderstanding rises exponentially.

 

Seventh, you have hinted at your academic qualifications, and I, too, have qualifications in science at the baccalaureate level, as well as internationally recognised qualifications in the application of Newton's Laws to daily occurrences. However, no one else has disclosed their training and experience in this field when attempting to rebut what I have said.

 

Therefore, I reluctantly decline your offer. I regret that I have to do that, as it sounds like a really interesting process.

 

With thanks, 

Old Man Emu

 

It seems to me that you re-opened the thread, saw that no one thought that PenName owed any money and decided to close the thread again.

[old man emu]

OK. I give up. Old Man Emu is an absolute dickhead who is not worth entering into discussions with. "No one thought ..." No one ever produced a rebuttal argument.

[Peter Piper]

3 hours ago, old man emu said:

No one ever produced a rebuttal argument.

May I interest you in a thought experiment and some Socratic questioning?

[old man emu]

3 hours ago, Peter Piper said:

May I interest you in a thought experiment and some Socratic questioning?

Read your PMs

[lee-wave]

On 04/04/2021 at 8:44 AM, Peter Piper said:

I'm late to this soiree , but that might actually allow me to assist you better. Allow me to state my credentials, fellow aviators: I graduated in the top 1% of highschool students, and studied a little physics at university and a little maths as a post graduate. I carefully read the thread that the administrator closed. It seems to me that it is important to Mr Emu to discuss this but, like most of us, he is distressed by not being listened to when he has gone to so much trouble. Mr Pen was rude and stated his case without listening to Mr Emu. I might also add that I was a member of the Philosophy Club at university and like precise language.

 

 

Beat you there... I graduated top 100% of primary school students in Fiji and studied a little bit of basket weaving...

[old man emu]

47 minutes ago, lee-wave said:

Beat you there... I graduated top 100% of primary school students in Fiji and studied a little bit of basket weaving...

If this was posted in a thread in the sister forum, I would have posted a ROFLMA emoji.

 

However in the climate of this thread such a post is not well received. Please don't throw 100LL onto a fire.

[jackc]

I just put an ‘out of service tag’ on myself for this one 🙂