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Science Experiments / Re: Wright brothers patent: "Plane stabilized in roll by a pendulum". Impossibility?

« on: 12/03/2020 18:37:16 »

but you may find some precursors of the "Navomatic" that used a simple pendulum.

When you find one by chance please post a link to it here.

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Science Experiments / Re: Wright brothers patent: "Plane stabilized in roll by a pendulum". Impossibility?

« on: 12/03/2020 03:33:59 »

1) Then post a link or a picture of that "simple wing leveller you have been using for the last 50 years" that works using the principle of the pendulum. I simply do not find such a  basic device.

2) In a coordinated turn the rod of the pendulum will always have the direction of the total lift (or the resultant of the weight and the so called centrifugal force), see the picture below. In the case of the ball, this will always stay in the middle of the tube.



As long as the turn is coordinated, no matter of the value of the bank angle, the pilot will always see the pendulum or the ball in the tube in the same position as if the plane flies non-accelerated in a straight line. How can such a device be used for measuring the roll angle?!

3) A simple example with a train and a pendulum inside it:

This is a rail-car in an uncoordinated turn (the resultant of the centrifugal force and the weight does not point perpendicular to the plane of the rails)



A pendulum in that rail-car will have the direction of the above mentioned resultant but its angle with the blue line will have nothing to do with the angle between the railway and the horizontal. The pendulum will just show to somebody in the car that the train is moving too fast, above the optimum speed of that turn.

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Science Experiments / Re: Wright brothers patent: "Plane stabilized in roll by a pendulum". Impossibility?

« on: 11/03/2020 21:13:19 »

"Anyway, you have comprehensively proved to your own satisfaction that the instrument everyone has used for the last 100 years, and the simple wing leveller I've been using for the last 50 years, doesn't work"

If by wing leveler you mean the glass tube and the air bubble inside this device:



which is basically a pendulum, it is well known that it is unable to indicate the roll angle. In the picture, the plane is banked to the right and the air-bubble (the bob of the pendulum) rests in the middle of the tube! The fact that you see the plane banked to the right has nothing to do with the air bubble (the pendulum) but with the gyroscopes inside the device. They detect the roll angle not the bubble.

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Science Experiments / Re: Wright brothers patent: "Plane stabilized in roll by a pendulum". Impossibility?

« on: 11/03/2020 03:11:39 »

No matter how you run the simulation, the trajectory of the pendulum is always chaotic regardless the damping ratio.

The pivot can not be placed in (0,0) because the center of rotation of an airplane is unknown. It depends on the number of people inside, their weight and position, the quantity of fuel, etc. If, I put the pendulum, in the simulation, only 1-2 mm away from (0,0) the bob has the same chaotic movement as in the animation above.

Even if I bank the plane only 5 degrees to one side, as the trajectory of the bob is dependent on the angular speed at which the plane rolls and its lateral acceleration, I get the same chaotic movement.

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Science Experiments / Re: Wright brothers patent: "Plane stabilized in roll by a pendulum". Impossibility?

« on: 10/03/2020 01:35:50 »

In a straight flight the pendulum does not work even if the speed of the plane along its longitudinal axis is constant and the plane flies in calm air parallel to the ground. As soon as the airplane starts to roll, even at constant angular speed, the pendulum gets a chaotic movement and has no tendency to align to the vertical or oscillate about the vertical of the place.



This is a simulation of a pendulum with a pivot rotating at constant speed along the circle of center (0,0) and radius=1 (as if it is inside a planes that turns continuously about its longitudinal axis while flying at constant speed). There is no tendency of alignment to the vertical. The bob has a chaotic trajectory from the moment it starts to move.

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Science Experiments / Re: Wright brothers patent: "Plane stabilized in roll by a pendulum". Impossibility?

« on: 03/03/2020 04:03:07 »

Look for a picture of  "turn and slip indicator".

This a very good remark.

"The turn and slip indicator can be referred to as the turn and bank indicator, although the instrument does not respond directly to bank angle." (https://en.wikipedia.org/wiki/Turn_and_slip_indicator)

If the plane takes a turn in a coordinated way the bubble of air will rest in the middle of the tube regardless the bank angle. A pendulum hanging from the ceiling of a plane will do the same thing. It will point toward the floor of the airplane (the rod stays perpendicular to the longitudinal and transverse axes of the airplane) no matter of the roll angle, assuming the centripetal acceleration during the turn remains constant. However, neither the bubble nor the pendulum can say anything about the bank angle and in consequence they can not be used as governors which correct the unwanted roll.

In the case of the Wright brothers, they correct the roll with a pendulum!

The turn and slip indicator is one more piece of experimental evidence that a pendulum or a bubble can not be used for measuring the bank angle of an airplane.

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Science Experiments / Re: Wright brothers patent: "Plane stabilized in roll by a pendulum". Impossibility?

« on: 01/03/2020 15:16:03 »

The pendulum of the Wright brothers is not about the acceleration the plane has along its longitudinal axis but about the angular acceleration when the aircraft randomly rolls about its longitudinal axis. The Wright planes were unstable in roll and the two inventors were looking for means to stabilize their flying machines. The US Patent no. 1,075,533 is about automatic stabilization governed by a pendulum whose pivot continuously goes to the left or to the right in a plane perpendicular to the longitudinal axis of the airplane.

Anyway, any example of a working device with a pendulum that is able to correct the bank angle of a plane, is welcomed.

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Science Experiments / Wright brothers patent: "Plane stabilized in roll by a pendulum". Impossibility?

« on: 29/02/2020 21:45:11 »

The Wright brothers’ patent: "Plane stabilized in roll by a pendulum" (US Patent no. 1,075,533). It seems impossible.

"The pendulum rocket fallacy is a common fundamental misunderstanding of the mechanics of rocket flight and how rockets remain on a stable trajectory." Robert Goddard fell into this trap as late as March 16, 1926 when he tested a liquid fuel rocket. The Wright brothers filed their US Patent no. 1,075,533 in February 1908,  tested the stabilizer in December 1913 and it worked flawlessly. Orville Wright even got a prize for his achievement (see the book below).

How is it possible? A pendulum with its pivot in an accelerated movement (like inside an airplane) does not tend to align to the vertical and can not be used as a reference like a gyroscope.

Is there another case when somebody succeed in stabilizing a plane in roll using a pendulum?

The 5 Wright brothers' patents:
- The US patent no. 821,393, granted on May 22, 1906, and its foreign versions, claim: (1) the method of wing warping, in particular, and the ailerons (already invented in 1868 by M. P. W. Boulton), in general, for stabilizing an aeroplane type machine in roll, (2) a movable vertical tail aimed at counteracting the adverse yaw generated by twisting the main wings, (3) a flexible front elevator for maintaining the pitch stability of the same machine, (4) various constructive details.
- The French patent no. 384.124, published on March 30, 1908, and its foreign versions, claim two more vertical rudders, placed in front of the main wings, one fixed and the other mobile. They were aimed at better counteracting the adverse yaw.
- The French patent no. 384.125, published on March 30, 1908, and its foreign versions, claim two additional vertical rudders, placed close to the tips of the main wings. Their purpose was also for eliminating the adverse yaw.
-> The US Patent no. 1,075,533, granted on October 14, 1913, and its foreign versions, claim automatic stabilization mechanisms: in roll, driven by a pendulum, and in pitch, governed by wind vanes (two models are proposed).
- The US patent no. 908,929 - “Mechanism for Flexing the Rudder of a Flying Machine or the Like”, granted on January 5, 1909, and its foreign versions, claim systems aimed at flexing the rudders of an aeroplane type machine for the purpose of modifying their lift.

Download link for "The Wright brothers’ patents and their low importance for aviation"



The book contains the patents of the Wright brothers in full.

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Technology / Re: In an egg boiler, why do you need less water to boil more eggs?

« on: 29/02/2020 21:24:57 »

The more eggs you want to boil in a pot the less water you can put there because the volume of the water plus that of the eggs can not be greater than the volume of the pot, as long as it is preferable the eggs should be completely submerged in water.

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Technology / Re: How to convert kWh to kW?

« on: 29/02/2020 21:15:37 »

kWh is measured in Joules
kW is measured in Joules/second
You can not compare two quantities that do not have the same unit of measurement.

A 1 kW electric motor will draw 1 kWh in one hour but the same 1 kW engine will only consume 0.33 kWh if it runs only 20 minutes.

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Physics, Astronomy & Cosmology / Re: Can a “right tetrahedron” represent a vector?

« on: 29/02/2020 21:04:05 »

A trirectangular tetrahedron can represent the modulus of a vector no matter how it is oriented in space. However, the same trirectangular tetrahedron can have an infinity of orientations relative to a reference system and in consequence can not be considered an equivalent of a vector.

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Science Experiments / Re: Writing a strong Research Paper

« on: 29/02/2020 20:51:33 »

There is no recipe regarding how to write a good science paper, as there is no recipe a film director can follow in order to make a good movie.
There are rules you have to follow but the majority of researchers learn them after writing 2-3 articles. However, this does not mean they will write only good article after their first three.

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General Science / Re: Can fire cast a shadow?

« on: 29/02/2020 20:41:35 »

The fire is a mixture of atoms and ions that emits light but like any gas can also absorb light and so a fire casts a visible shadow especially if it is illuminated with a source of light that emits a color or colors that are well absorbed by the ionized gas called fire.

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Question of the Week / Re: QotW - 19.10.20 - Why does wiping my car windscreen turn water to ice?

« on: 29/02/2020 20:26:44 »

A thin layer of water freezes more quickly that a thick layer.

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Famous Scientists, Doctors and Inventors / Re: Who is the father of physics?

« on: 29/02/2020 20:11:50 »

Marie Curie is the mother of radioactivity. Its father is Henri Becquerel.

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Famous Scientists, Doctors and Inventors / Re: Who is the father of physics?

« on: 28/02/2020 09:54:32 »

The father of modern physics is Newton.

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New Theories / Re: Hayseed Electron

« on: 28/02/2020 09:34:34 »

"An electron in a low energy configuration(state), is about 18-20 amps.  A proton is about 30,000 to 40,000 amps.  Both can be induced or compressed to much higher amperage."

I = Q/t

As they have the same charge, the electrons and protons produce the same current while traveling at the same speed (the same flow). If an electron is 20 amps then a proton is 40000 amps it it travels 2000 times faster than an electron (the flow of protons is 2000 greater)!

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New Theories / Re: A new explanation of the electric current

« on: 28/02/2020 09:20:57 »

If an an electrical discharge through the air is largely carried by positive ions then, I guess, a current of air (wind blowing) should be detected between the electrodes.