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23 November 2024 15:27
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Welcome to the gyroscope forum. If you have a question about gyroscopes in general,
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| Asked by: |
Nitro |
| Subject: |
Obsevations |
| Question: |
Dear all,
For clarity, can I suggest that from now on all posting here refer to the spin of a gyro wheel round its axis as “spin” and its rotation (like that around the proverbial Eifel tower) as “rotation”.
Blaze, there is a lovely clear example of a demonstration of the missing centrifugal force of a precessing gyro right here on this site in the videos of the Laithwaite Christmas lectures. go to gallery/RIGB Christmas lecture or click for web page:-
http://www.gyroscopes.org/1974lecture.asp
Select number seven and observe,observe, observe. Then come back to tell me if you still don’t think that there is a problem with gyros and the centrifugal force exhibited by their rotating mass.
I am sure, Blaze, that most here do not believe that a spinning mass has no momentum. I believe you were referring to the observations made here that the gravitational or forced rotation of a spinning mass (precession) exhibits the effect of having no/reduced centrifugal force (as would be displayed by something like a bolas). I have found that great care is needed to test exactly what centrifugal force exists from the rotating mass of the gyro processing round the proverbial Eifel tower. Most gyros used for examination of precessional rotation have a fairly short shaft so any orbital displacement of its centre of rotation will be fairly small and care is needed in the observation of what centrifugal force exists . Nitro’s first law (a gyro will precess every force applied to change its axial angle – including the ones you haven't thought of) waits to catch out the unwary.
A university demonstration shows that even a pinnacle of our scientific teaching should not solely be relied on for understanding. A classic example of what happens to the unwary observer of gyros can be found here:-
http://www2.eng.cam.ac.uk/~hemh/gyroscopes/icegyro.html
It claims to show that there is no change in the expected centrifugal force exhibited by a rotating gyro because an orbit is described by its aluminium disc base on the air table. However, it should be clear to anyone slightly versed in the art that there are two things wrong with this demonstration.
1. The weight of the non gyrodynamic components of the assembly - the gyro’s cage, bearings, shaft and inner, less gyrodynamic mass - has not been counterbalanced on the opposite side of the pivot point to remove any unbalanced weight influencing the resulting observation of centrifugal effect and:-
2. Careful observation of the centre of rotation shows it is is way off where it should be given the mass of the gyro and its rotational speed. The page even has a diagram, showing where the centre of rotation might be expected to be, that confirms this!
In 2007 Emma Wilson submitted for her MEng. thesis the usual churned out math she thought explained all of the motions of above video and, just to stay part of the scientific herd, she added an acerbic diatribe against Laithwaite’s Christmas lectures that were intended to interest children. As the Royal society had already said his lecture and views were incorrect her thesis was a duplication of this and, thus, a waste of her education and taxpayers money even if it were true. That her conclusions were wrong shows a disappointing lack of supervision and guidance of her observations by Dr Hugh Hunt and a sad perpetuation of the “scientific herd syndrome” that has been repeated since the time of Galileo. Dr Hugh will presumably wait until some Pope of the church of science issues a Papal Bull to tell him it’s alright for him to have a Galileo moment like Laithwaite. You can’t blame Dr Hugh as, If he avoids acknowledging that the earth orbits round the sun and waits for a Papal Bull, he can save himself from being spat at and having his career ruined by fellow members of his church (herd).
The mass hysteria caused by the “scientific herd syndrome” can be observed to this day with the “global warming” nonsense. The expression “global warming” you will observe is now more and more often newspeaked into “climate change”, by the IPCC and their cancerous warmist metastases. This is because it is becoming more and more obvious to even the least attentive observer that there has been no global warming for some seventeen years. Thus the IPCC needed a new term to ensure we can continue to be panicked, not by drowning polar bears, vanishing Everest glaciers or London turning into Venice at some vague time in the future, but by every extreme weather event that occurs now – much better. This will make most of the congregation revere still more the warmist religion that caused their fears and enable the congregation to be conned into paying yet more into the warmist’s collection plate to prevent their sins from destroying them.
These climate geniuses cannot even get the weather right for a week or two in the future and yet with the “chicken little” computer models used by the IPCC and its warmist metastases they claim they can tell us the sky is defiantly going to fall in the next seventeen years or so despite being proved totally wrong for the last seventeen years. Listen by all means to other’s perception of scientific truth (be it the third law or global warming) then go away, carry out your own checks and tests, and observe, observe, observe for yourself! Then; go away and look, again, for the things you haven’t thought of.
Kind regards
Nitro |
| Date: |
9 April 2014
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Answers (Ordered by Date)
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| Answer: |
Glenn Hawkins - 10/04/2014 00:26:44
| | | Nitro Good morning,
Spin is OK, so is gyro rotation. Hub rotation (Sandy’s gift) is better as it is explicit and self explanatory. Pedestal is rather perfect and the tower isn't, but I don't have an isue .
The demonstration of the missing centrifugal force is a ruse. There is no evidence if you understand what is happening.
Mechanically: Blaze knows. As the flywheel drops, it twist its weight back upon the pedestal. Think of having your right hand on the top of a non-spinning wheel and pushing; think of having your left hand on the bottom of the wheel and pulling with it. The wheel of course will twist and the shaft running through it will twist down on the pedestal. That is what a precessing gyro dose. It is not at all just a straight down force on the flywheel, but a converted twisting force. The pedestal is connected to the metal plate. See:
http://www.gyroscopes.org/1974lecture.asp number 7 time 10:28: 00)
The flywheel twists the pedestal. The pedestal attached to the plate, twist the plate and forces down on the back of the plate. The results of gravity then rest on the back edge of the plate from a twisting action.
There is more to muse over. Such as whenever the pedestal is extended over the ledge and the flywheel is positioned in the opposite direction hovering over the table, why then doesn’t the gyro twist the attached plate over the edge? It is just that the thing is perfectly balanced. It applies a twisting force of resistance; not and opposite acting force that would upset its equilibrium. Equilibrium is rather the perfect word. The twisting force from precession is a balance that does not cause action, or movement of any kind. It reacts to counter against a force, as he earth does when you jump up and down on it.
The video # 7 is a ruse.
Yes, as you reveal; the Wilson video is the work of a soap salesman who wants a degree.
http://www2.eng.cam.ac.uk/~hemh/gyroscopes/icegyro.html
However, I have found plenty of what is being wrongly call centrifugal force. Do not rely on Professors Liftwait’s ruse video of a tower with pointed medal legs on soft ice watery ice. To find the truth put crushed ice inside the cavity of the Taco pedestal, put the pedestal on smooth Formica or glass and watch the pedestal follow the gyroscope in a circle. It is being pulled, but NOT by centrifuge (Thank you Harry). It is being pulled by the direction of hub rotation, that is to say pulled by momentum.
Centrifuge is the pressure from an object that is deflected from its tendency to travel in a straight line. Lessen the containment of deflection, by allowing the pedestal to slide atop crushed ice and you will get a directional movement caused by momentum that here would wrongly be thought of as movement by centrifuge.
It is OK Nitro. We love you anyway.
http://www.youtube.com/watch?v=3jmdLpsK_k8
Good evening Sandy. From time to time your face comes into my mind and I like that and very much. I think of, and respect all the work and research you’ve done even when my mind dose not always completely comply with everything.
Have a great evening Nitro and all,
Glenn
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| Answer: |
Glenn Hawkins - 10/04/2014 00:50:24
| | | Excuse me. When the gyroscope is upside down the same thing is happening. Imagine your hands twisting in resistance to the gyro falling and you should be able to follow the twisting force back to the rear tip of the plate.
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| Answer: |
Blaze - 10/04/2014 03:14:25
| | | Good explanation of what is happening in video 7 Glenn. I may have "wordsmithed" it differently but would have essentially said the same thing.
"Such as whenever the pedestal is extended over the ledge and the flywheel is positioned in the opposite direction hovering over the table, why then doesn’t the gyro twist the attached plate over the edge?"
You are correct about the balance. When the gyro is precessing, whether it is hanging over the table or over the end of the aluminum plate, it is essentially trying to push the gyro end of the plate down against the edge of the table. The weight of the gyro is "transferred to the pivot" and therefore the gyro is pushing down through the center of the gyro pivot. It would be the same as if the gyro were actually sitting on top of the pivot. The plate would be trying to rotate about a point at the end of the table and working against all of the plate that is on the table. It is a matter of balance and leverage. The distance that the plate could be pulled out past the edge of the table was carefully marked. I would think that it wouldn't take much more distance at all for the system to be out of balance when the gyro was hanging over the table while precessing.
When the gyro is not precessing and pinned in a horizontal position and hanging over the aluminum plate, the gyro weight is NOT transferred to the pivot which makes the force applied to the plate further out than the pivot. That is why it would topple off the table taking the plate with it.
As for centrifugal force, I don't know the dimensions of the gyro but will make the following assumptions. Gyro flywheel weight and axle is 2 pounds. Distance from gyro pivot to center of gyro flywheel is 4 inches (probably generous). The time to precess 360 degrees can be seen from the running time on the video and is almost exactly 4 seconds. Doing the math and assuming for sake of argument that full centrifugal force is present (worst case scenario) this means that the centrifugal acceleration is a whopping 0.228 newtons or about 1/20 of a pound, essentially nothing. Centrifugal acceleration and therefore centrifugal force is a squared function. The reason it is so pitifully small for the gyro in the video is because the gyro is precessing at 1/4 turn per second. To slow to generate any significant amount of force.
According to the professor when stopping the gyro it is as "gentle as a lamb". When doing the math for stopping the gyro in 1/4 second you get about 0.58 Newtons which is about 2 ounces of force to stop it. Definitely "gentle as a lamb" alright.
regards,
Blaze
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| Answer: |
Blaze - 10/04/2014 03:43:16
| | | whoops, guess I can't count.
The time to precess 360 degrees can be seen from the running time on the video and is almost exactly 3 seconds (not 4 seconds). Redoing the math give a centrifugal acceleration that is still only a small 0.405 newtons or about 1/11 of a pound or about 1.46 ounces, still essentially nothing.
When redoing the math for stopping the gyro in 1/4 second you get about 0.77 Newtons which is about 2.78 ounces of force to stop it. Still "gentle as a lamb".
cheers,
Blaze
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| Answer: |
Glenn Hawkins - 10/04/2014 04:04:27
| | | Good job, Blaze!
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