|
Main Forum Page
|
The Gyroscope Forum |
27 November 2024 10:56
|
|
Welcome to the gyroscope forum. If you have a question about gyroscopes in general,
want to know how they work, or what they can be used for then you can leave your question here for others to answer.
You may also be able to help others by answering some of the questions on the site.
|
Question |
| Asked by: |
Glenn Hawkins |
| Subject: |
Bewildering Actions & Astonishing Notions |
| Question: |
One of the most astonishing actions I’ve ever realized I actually came to pay attention to only a few days ago. I overhung a very fast spinning gyroscope from a pedestal, but hung it unusually at 45 degrees to vertical —not the 90 degrees, or right angle we usually begin with to produce horizontal precession about a pedestal. Beginning from 45 degrees the gyro rose to an eventual zero degrees at vertical and stood there upright like a toy top, the tip of its axel hub spinning inside the cupped top of the pedestal and its rotating wheel directly above horizontal to the table top. I find the ramification of this action, this rising gyroscope, once examined become extraordinary to the extreme and offers an unavoidable truth. Let us explore them, these ramifications.
It had been reasoned that an over-hung gyroscope powered only by the pull of gravity must eventually tilt into gravity at least to some small measure over a period of time and so the gyroscope could descend slowly this way as it precessed… but it could never rise against gravity without mechanical assistance. Gravity pulls downward not upwards. What force was there to lift the gyroscope? Moreover how could it utilize the force of gravity to rise against that very gravity that is pulling it downward? That is not possible. Then from where does this upward lifting force come? There are only two forces at play in this system, the angular momentum in the spinning wheel and gravity. Because the energy that causes the gyro to rise cannot be gravity, the energy must come from the angular momentum in the wheel. There is no other source of energy available in this gravity-powered system to provide the lift that is observed.
At this point we begin to realize the astonishing condition that some of the angular momentum is not conserved, but is converted to lift the gyroscope in a curving action to higher elevations. Measuring elevation only the gyroscope changes angular momentum to an increasing leaner elevation rise. If the rise against gravity weren’t baffling enough, in physics in a closed system the conversion from angular momentum to linear motion is impossible, yet in reality you can watch it happen with your very own two peepers.
Bewildering? Not amusing? Says whom?
Glenn,
|
| Date: |
10 August 2007
|
| report abuse
|
|
Answers (Ordered by Date)
|
| Answer: |
Ram Firestone - 11/08/2007 05:51:17
| | | This first question you have to ask is why a top typically rises while a gyroscope typically drops. My theory is a top rises because it has friction with the floor. The spinning point of the top at an angle works a bit like a wheel. This actually puts a lateral force on it and it therefore precesses upwards. All it takes s a slight amount of friction to do this. Since a gyroscope has a frame, its tip is no longer acting like a wheel pulling the gyroscope around. However if the frame starts to spin in its cup on the pedestal I can see the same thing happening so this might not be as astounding as it would seem.
You have to remember precession works both ways. All forces that rotate a gyroscope cause it to precess in one direction or another. The reverse is also true. If there is some sort of resistance that is hindering a gyroscope’s precession it will start to loose its stabilizing properties. In the extreme case where a gyroscope is not allowed to process at all, you can actually spin it freely (assuming everything is strong enough and it doesn’t explode).
|
| Report Abuse |
| Answer: |
Glenn Hawkins - 11/08/2007 11:49:08
| | | In your first paragraph you may be right. I concluded the same thing in another type of experiment. Anyway very good reasoning and explanation from you.
The second paragraph would be common knowledge except for the last sentence.
You said: “In the extreme case where a gyroscope is not allowed to process at all, you can actually spin it freely… .
What does that mean? If it is not precessing why couldn’t you spin it freely? This question then brings us to a point. During precession do you think by increasing the RPMs of the disk with an internal motor you would find resistance to the increase of rotation, or do you think that precession would merely slow down and that there would be only inertia resistance to overcome while increasing the RPMs?
I’ sending my computer to the hospital to day. It is pretty sick. I’ll talk again if and when it can be revived.
|
| Report Abuse |
| Answer: |
Ram Firestone - 11/08/2007 15:08:41
| | | "What does that mean? If it is not precessing why couldn’t you spin it freely?"
Sorry I didn't explain this very well. As they say a picture is worth a thousand words. A video should be worth 10,000 :-)
http://www.youtube.com/watch?v=iu6kp6fSc3M
Let’s leave behind the discussion on whether this device actually works for a second and just observe what’s happening. Notice they have four motorized gyroscopes (flywheels or whatever you want to call them) securely bolted to this cross. Depending on which way the gyroscopes are spinning rotating this cross should cause them to precess either up or down (I’m presuming up given what they are trying to do). However they can’t rotate up (or down) because they are physically prevented from doing so by the metal frame, so this whole device can now be spun feely with minimal apparent resistance by the gyroscopes.
|
| Report Abuse |
| Answer: |
Nitro Macmad - 12/08/2007 20:45:14
| | | Dear Glen,
Ah! Closer and closer, by recognising the importance of anomaly.
As I am sure you have found; the reason a gyro released with its axis horizontal on the classic Eiffel tower (preferably with a motor to maintain its spin speed) slowly droops is that the horizontal frictional drag on the gyro’s pivot point opposing its axial rotation is itself precessed into a downward direction of the axial angle (the dreaded droop). This can simply be confirmed by increasing the friction (which will speed up the rate of droop) by, for example, applying a slight clamping pressure on the pivot point with your finger.
Some of us, Arthur, have had the ability to take it (the finger) out and do something in the way of practical, as opposed to bookish, research. Your acidic comments to Sandy show that your ability is being wasted yet again in downing others while you continue to blind yourself to anomalies that would benefit from your abilities. How sad!
Glen, the upward precession is an important anomaly caused by the oddity; that the precessional angle in an upward precessional cone (in some ways like the lift/drag resultant of the autorotating blades of an autogyro being, surprisingly, in front of its blades) of a gyro, having its axial angle acted upon by the force of gravity, has its resultant precession slightly upwards. It shows, like some of Laithwaite’s work, that not only will a gyro (our type not autogyro) rotate around something other than its centre of mass but, much more incredibly, it shows that, in this case and others, it can raise its centre of mass TOWARDS its primary precessional force and move upwards AGAINST the force of gravity.
No cigar yet, boys - but we’re ever closer!
Turning now to you, Ram,
That Nitro’s first law is still not appreciated by everyone is demonstrated by the heroic, but rather misguided, practical experimentation shown in the video at the listing Ram gave…… http://www.youtube.com/watch?v=iu6kp6fSc3M
Thank you Rameses so much for listing that. As you said; a picture says…..
Remember Nitro’s first law (a gyro will precess every force applied to change its axial angle – not just the force you first thought of)! In the video, therefore – and read this very carefully for I shall write this only once –
The force applied to change the gyro’s axis by (in the video) the torsional force rotating the shaft on the vertical axis (the “main shaft”) causes the gyros to try to precess upwards. As they are unable (due to their non pivoted mountings) to move their axial angle upwards there is the equivalence of downward force on their axial angle. This downward force is precessed into an equivalence of a force acting in a rearward direction against the mainshaft’s rotation. This is equivalent to the ordinary inertia of a mass (equal to the mass of the gyros) which is overcome by the torsional input to the mainshaft. Lo, you are back to the beginning again.
What this means is that when a force precessed (sorry Sandy!) assembly of gyros are not free to pivot in their normal precessional directions, the whole assembly acts as though it was just an assembly of fixed weights (instead of spinning gyros) with the exception of an unseen upward torque being applied to the assembly as the gyros try to precess their axes upward.
Daft and dangerous yes! But a bold attempt to get to grips with a difficult subject.
Kind regards
NM
|
| Report Abuse |
| Answer: |
Sandy Kidd - 14/08/2007 07:18:59
| | | Dear NM & Glen,
“What this means is that when a force precessed (sorry Sandy!) assembly of gyros are not free to pivot in their normal precessional directions, the whole assembly acts as though it was just an assembly of fixed weights (instead of spinning gyros) with the exception of an unseen upward torque being applied to the assembly as the gyros try to precess their axes upward.”
Nitro, I forgive you, because you know better.
However you made a fundamental point with respect to tethered gyroscopes.
In all the devices I have ever built the gyroscope/flywheel has always been free to find its own path.
I will enlarge upon that if I may.
Unlike many experimental devices I have seen, I have found it necessary for the gyroscopic fulcrum to be on the axis of the system rotation, and the gyroscope and its support bearings free to move vertically if the gyroscope demands this.
However, in the devices I have built which have shown promise, whilst the gyroscope can be made to deliver large changes in angular momentum, without any apparent movement in the vertical axis I have found it necessary never to restrain or clamp the gyroscope.
The triangle must not be closed.
As you suggest, if the gyroscope is clamped its torque reaction is fed into the body of the machine and lost.
Regards,
Sandy
|
| Report Abuse |
| Answer: |
Glenn Hawkins - 16/08/2007 16:45:25
| | | If we keep at it we are going to be accused of cognitive coherence by the un-amused crowd —to them outlaws every one of us. Yours were wonderful replies every one of them.
I do not believe all the reasons given; the events that cause a gravity powered ‘gyro’ to rise are understood. I think what happens is what has been explained, but more than that, more reasons than that. It is still a lovely little mystery.
Glenn,
|
| Report Abuse |
| Answer: |
Ram Firestone - 16/08/2007 17:26:29
| | | "The force applied to change the gyro’s axis by (in the video) the torsional force rotating the shaft on the vertical axis (the “main shaft”) causes the gyros to try to precess upwards. As they are unable (due to their non pivoted mountings) to move their axial angle upwards there is the equivalence of downward force on their axial angle. This downward force is precessed into an equivalence of a force acting in a rearward direction against the mainshaft’s rotation. "
I think you are saying the same thing as I did in a more general way.
|
| Report Abuse |
| Answer: |
Glenn Hawkins - 17/08/2007 16:24:31
| | | Hello Ram,
Let us reconsider the original subject. First off: I am reversing myself after carefully rethinking. I’m now sure the spinning of the axel hub inside the cup of the pedestal makes no difference. It does not cause lift, only an unrelated drag by friction.
The gravity powered, high speed, 45 degrees set-up seems oh so simple, but is it? If you concentrate on the little axel hub spinning in its pedestal cup pressed forward by horizontal precession you realize that it spins up grade into the cup rim. If anything this should cause the hub to crawl, or spin its way upward, out of the cup. This would twist the bottom of the gyro 1/32 of an inch upward, but not twist the top of gyro upwards much if any. That the gyro can rise and straighten full length to vertical can’t be attributed to the friction in the upward slope of the pedestal cup even though the hub may rotate constantly. The free spinning in place just does not lift. Even if it could such a lift couldn’t be higher than the pedestal cup rim, or about 1/32 inch.
I sat up a gyro as if it were a top. I spun it up and sat the axel at a 45 degrees to vertical on the bare table top leaving the ‘gyro-converted-to-top’ free to do whatever it chouse. As the frame begin to rotate the little round hub setting on the table began to rotate. The over all result was that the hub rolled like a wheel subscribing a rather large circle around the table top, while the top scribed the same circle, but on the opposite side at a higher elevation. Think of two balls tied to together and rotating around one another in space, except one ball is higher and the other lower. The ‘gyro-converted-to-top’ rose from 45 to –o- degrees. It seemed to push itself upright from the table, and I think this is because as the wheel wobbled around in the air it kept having to overcome a new and higher plain of spin its wobbling created and this is what lifted it-- angular momentum.
When we try this same 45 beginning degrees experiment with a gyro and pedestal, rather than ‘a gyro-converted-to-an-upright top’ we see that the pedestal does not move due to table top pedestal friction. The axel hub is not free to spin itself all about the table, but must remain in the motionless cup of the pedestal. Unlike the ‘gyro-converted-to-top’ the wheel does not seem to wobble, but rather circle the pedestal, but the circling is like a wobble in that the alignment of the wheel is always changing planes just as in the wobble. This seems to be the reason the gyro is able to elevate itself to vertical and again this is by using angular momentum for a curving though linear lift within a closed system. Oh yeah! This is against the law.
I believe this hypotheses is likely correct, but still I'm back to Bewildering Actions & Astonishing Notions. I'm studding all the good and well thought out responses individually. I hope to speak to all of them.
Glenn,
When we try this same 45 beginning degrees experiment with a gyro and pedestal, rather than ‘a gyro-converted-to-an-upright top’ we see that the pedestal does not move due to table top/pedestal friction. The axel hub is not free to spin itself all about the table, but must remain in the motionless cup of the pedestal. Unlike the ‘gyro-converted-to-top’ the wheel does not seem to wobble, but rather circle the pedestal, but the circling is like a wobble in that the alignment of the wheel is always changing planes just as in the wobble. This seems to be the reason the gyro is able to elevate itself to vertical and again this is by using angular momentum for a curving though linear lift within a closed system. Oh yeah! This is against the law.
I believe this hypotheses is likely correct.
Glenn,
|
| Report Abuse |
| Answer: |
Ram Firestone - 18/08/2007 19:29:08
| | | “The ‘gyro-converted-to-top’ rose from 45 to –o- degrees. It seemed to push itself upright from the table, and I think this is because as the wheel wobbled around in the air it kept having to overcome a new and higher plain of spin its wobbling created and this is what lifted it-- angular momentum.”
Watch this video. Go to about 3:13 in the video. I’m sure you are familiar with this kind of precession:
http://www.youtube.com/watch?v=dCcfKBfmyP4
This is the same thing as a top pulling it self around the floor. It tends to bring itself upright because it’s friction with the floor is pulling itself around. If you put the gyroscope on a stand it’s not so obvious this should still work. However I still believe even spinning in it’s small cup is provides enough force to bring it upright due to precession.
|
| Report Abuse |
| Answer: |
Glenn Hawkins - 18/08/2007 20:41:58
| | | You have offered new insight; a different way of considering things and you should be applauded, not argued against. I consider argument here is detrimental to our search for more knowledge. I don’t see it your way, but I was able to see through your eyes and the diversity was good. I can argue several points in opposition to your conclusion and I think convincingly, but as I said I don’t think I should. I merely pointed out an anomaly that is difficult to repeat. You are especially smart. I noticed that a long time ago. I look forward to more posting from you. Thank you for showing me how you view this particular phenomenon that I still say is most extraordinary and not fully understood with any certainty. (The subject was how a gravity-powered gyro rises against gravity, unless it uses the only other available source energy, which is angular momentum used in an unlawful way.) The several of us here in this thread have beaten this subject around in different ways for each to consider and that’s about as good as it gets. Diversity is our friend.
Glenn,
|
| Report Abuse |
| Answer: |
Glenn Hawkins - 18/08/2007 21:26:11
| | | Dear Nitro,
The added friction to oppose rotation that then causes a droop is a good exercise in thinking. I myself use the four (not two) directions of nutation-- all of which obey your Law precisely. I have observed large nutations on the internet caused to act under certain conditions.
Precession is a system of balanced forces. When an over hung gyro is suddenly loosened to fall it gains speed (a little) beyond the speed that would be the correct speed in the balance of forces. The gyro compensates by bouncing forward faster than it should in a balance situation (a little). The gyro reacts again by bouncing upward. Then the gyro reacts again by bouncing backwards-slowing precession. It bounces faster forward faster, bounces upward, bounces backwards slower, and then bounces upward to repeat these four actions. This is all according to your law and you can watch it working if you can find the right nutation presentation on the Internet.
When you applied pressure with your finger to the hub in the pedestal, you did two things. You slowed rotation and you slowed precession. Slowing either causes the droop that you explain so well. Our understand is kind of like the old flirting question to start a conversation. “Didn’t we used to go to different schools together?” So, we view the same thing correctly, but through different peepholes. Diversity is our friend again. “Lo, you are back to the beginning again. The importance of recognizing anomalies.” Yeah! Oh yeah.
Kindest Regards,
Glenn
|
| Report Abuse |
| Answer: |
Glenn Hawkins - 18/08/2007 21:37:33
| | |
“… I have found it necessary never to restrain or clamp the gyroscope.
The triangle must not be closed.
As you suggest, if the gyroscope is clamped its torque reaction is fed into the body of the machine and lost.”
I couldn’t have said it as well, Sandy. Keep it up.
Regards,
Glenn
|
| Report Abuse |
| Add an Answer >> |
|
