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27 November 2024 13:58
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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.
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Question |
| Asked by: |
Nitro MacMad |
| Subject: |
Why "impulse drive" is possible. |
| Question: |
Dear All,
As there seems to be a lull in the propulsion mail I thought I would see if there are any scientists out there I could tax.
Sir Isaac Newton taught us why an apple falls down from the sky - and he taught much, much else. Trouble is that because many of his observations were so astonishingly astute his observations have become regarded as “laws”. Far, far worse they have become to most scientists and to most people that have learnt even basic physics, a religion. Like most religions, the “church of science” believers are vehement defenders and will fight any suggestions that a basic tenet needs to be re-examined.
In the seventeenth century the Catholic Church believed that God had created the Earth and man and therefore He (or She - to choice) must have made Earth the centre of the universe for us, His living creations. The sun and planets therefore must rotate about it. Galileo dared to suggest instead, that his own observations with his own made telescope would seem to show that the earth and planets circled the sun. He got the kind of “encouragement” that I, and surely others who have learned to doubt the “opposite reaction” part of Newton’s third law, have “enjoyed”.
Like in the Catholic church of Galileo’s time, the “church of science” now has religious mantras that are chanted if attacks on a tenet causes wavering amongst followers. When the “church of science” feels threatened when its tenet of “the third law” is questioned, the favourite mantra that is chanted is “conservation”. This is usually the “conservation of angular momentum” mantra, or even the “conservation of energy” though it could just as well be the “conservation of conservation” mantra as none of these mantras try to answer or have any relevance to “the question”.
“The question” is:- Why does the fact that the “opposite reaction” part of the third law doesn’t work with precession seem to be covered by a cloak of invisibility to the “church of science”? A further question that the “church of science” needs address is why, although the lack of opposite reaction in precession has nothing to do with conservation, conservation is always thrown in to any explanation and, although conservation is undoubtedly going on, it does nothing to explain where the missing “opposite” part of the third law vanished to.
So let me ask “the question” in descriptive form and please let me have your views - perhaps I shall learn that there are not just Mantra chanters out there but independent thinking people that can examine preconceptions. Perhaps I shall even have to re-examine my own preconceptions.
An example of “the question”:- if extra down force is applied by the rear of the rotor of a hovering helicopter why, if the “opposite reaction” law applies, does the craft not tilt and fly forwards but instead tilt and fly sideways? Yes, I do understand the other control adjustments that need be made but they don’t detract from the question so don’t try muddying an answer with that! I am sure that you don’t really need further extensions to this theme but to labour the point:- Why, if the opposite part of the third law applies, when a force is applied to alter the axial angle of a top or gyroscope, its movement of axial angle (reaction) is not opposite, as the “third law” insists it must be, but 90 degrees round?
The above are really trick questions as the answers are known by all of us but seem by some strange communal subliminal agreement to have been hidden by the “church of science” magic cloak of invisibility”.
Kind regards
NM
PS The answer, of course:- What we, for simplicity, call “precession” causes the reaction to the applied force to occur 90 degrees round. Let me repeat that:- the reaction to the applied force occurs 90 degrees round.
So that’s not opposite then? Er - no! Conservation of something? Er - yes, of course!
So the third law, but not conservation, has serious problems when the opposite part tries to be fitted to the rotation of a rotation (precession) and that is precisely why reaction-less drive is possible using gyros.
Or do you have a different view??????????????????????????????????????????????????
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| Date: |
26 August 2004
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Answers (Ordered by Date)
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| Answer: |
Ram Firestone - 31/08/2004 04:29:06
| | | I suppose I have a different view. The reaction is still opposite. If you take each point on the rim of your gyroscope, helicopter (or whatever) it is indeed moving roughly in the same direction you initially pushed it. For instance say you are looking down upon a gyroscope that is rotating in the XY plane such that the Z-axis points towards you. Now if you apply a force upward (towards you) on a single point of the rim and follow that point around 90 degrees as the gyroscope rotates, you can see if the point continues to move towards you it will cause the gyroscope to tilt assuming the center is held in place. This still doesn’t break the equal and opposite part of Newton’s third law. In fact if there is nothing holding the center of the gyroscope in place (such as gravity in the case of the helicopter) the gyroscope will not even precess. Instead the whole thing will travel towards you. Again equal and opposite. I think the main thing is you can’t consider a gyroscope as a single blob of mass. You have to break it up into all it’s distinct points to explain why it works. At least that’s the way I see it.
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nm - 06/09/2004 07:31:07
| | | Dear Ram,
I used the helicopter analogy as it is big and, I thought, easier to picture.
You describe how a single point reacts according to the third law, I believe that the whole structure does not. The whole gyro and its potential for getting round the third law is where the afore-mentioned “cloak of invisibility” presently rests for most people.
Your space gyro, having no fixed pivot and having a force applied at one point would indeed, after a small amount of initial inertial precession, move away linearly and therefore mostly seem to follow the third law. However, you have created a test to produce an expected result.
Torque creates precession and a better test, would be to apply a force at one end of the axis and an opposing force at the other axis end. The gyro will, of course, like the helicopter example, precess this torque and the shaft axis will react gyro-dynamically by twisting at 90 degrees to the applied torque. This example can be far more easily demonstrated terrestrially by horizontally turning a gimballed gyro with its axis starting horizontal. Although precession is not a linear displacement in itself, it has long been known that a torque can be converted to a linear motion by a crank (yes, yes, like me if you must).
The 90 degree displaced precessional reaction, though clearly not opposite, is always described by “science” as though it is, somehow, opposite. This is usually accompanied by much chanting of a “conservation mantra”. Conservation there is a-plenty in precession but somehow science uses conservation to hide from itself that a (whole) gyro axis produces a torsional reaction that is not opposite to the torsional action.
Perhaps we should be teaching:- Every action has an equal and opposite reaction except (when a torque is applied to the axis of gyros, tops, helicopters and) for anything that rotates as they have a “not opposite opposite”. Though this completely sods up what was a nice universal “law” and doesn’t have the nice simple metre of the original “third” somehow.
That the fabulous opportunities this simple, but currently invisible, anomaly makes possible have been for so long overlooked can partly be blamed on the blind chanting of scientific mantras. Who, but nutters like me in sheds, would be so stupid as to look for something that scientific mantras say is not there. Who but nutters in sheds would waste their time to search out something Newton no less, via his “laws” says cannot happen? The inventive genius (alright, nutter in a shed) who “cracked it”, is who.
Kind regards,
NM
P.S. Sorry to be a bit cocky but wouldn’t you be?
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Ram Firestone - 07/09/2004 23:00:56
| | | I guess my point is that if you take each point on a gyroscope and follow it as forces are applied it is easy to see how precession might occur. That’s not to say that this is the full explanation, however so far as I’ve seen the only thing a gyro has ever done is move around it’s center of gravity. If you can somehow produce linear motion out of a gyroscope then more power to you. I have thought of many ideas along these lines but I am certainly not convinced that it is possible. In fact I would tend to believe it is impossible. This belief is not entirely based on Newton either. Many experiments by believers, non-believers, scientists and as you say “nutters in sheds” have never shown any reproducible linear motion from a gyroscope. As I said before I hope it is in fact possible, but so far no proof has been offered by anyone.
Good luck
Ram
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NM - 14/09/2004 18:02:51
| | | Dear Ram,
It has always been “put up or shut up” with this device, and understandably so. When I first successfully used gyros to move a weight and the machine that carried it (without “stick slip”) in the same direction I could hardly believe it. Yes! I repeated that first test (and many others) many, many times. I am sure you can understand that, like the rest of the world will at the moment, I believed that the first test would prove to be some kind of mistake. That was years and years ago.
Having shown the early devices to trustworthy friends who humoured me politely and then got on with the important tasks of youth I later became convinced that more able people than me (Jones and Laithwaite et al) were about to “crack it”. So, I got on with the more important tasks of youth myself and put the whole mind hurting thing aside. Laithwaite is now sadly gone and I am probably getting close to the end game myself, so despite now hating the engineering with a passion and suffering what I can only describe as protracted periods of “inventors block” I am trying to push on so that the “fast repeater” mechanism can, hopefully, be shown in my lifetime.
The single stroke machine and the slow repeater have been made and have chugged along happily on my workbench. However, I am only too aware that what is needed is something that will dramatically show what is claimed. Simple test rigs that confirm my own expectations are clearly not enough to break through others preconceptions. The “fast repeater” will be very, very clear and, although (due to my “carp” engineering skills) its construction has suffered some very exciting “fast dismantling” causing me to get rather disheartened, it is getting closer.
It has been heartening that those who have discussed this on this site have restrained from cries of “B.S.” indeed some, like yourself have been kind enough to give expressions of good luck - though, somehow I think a wish of “good engineering” might be more use at the moment.
Kind Regards
NM
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Sandy Kidd - 21/09/2004 14:44:58
| | | Shed dwelling persons,
I am assuming Newton did say “equal and opposite” and not just “equal”?
We all agree that a gyroscope reacts at right angles to an applied force, and it is this uniqueness that makes it a gyroscope.
It is just a weird anomaly that has always been accepted as being there.
NM suggests impulse / inertial drives are possible.
From what I have seen, impulse / inertial drives are not only possible they are inevitable.
However I get the impression from some of the offerings to this "Forum" that there are those of you who appear to be trying to preserve the Laws of Motion at any costs
There is no denying that in all earth bound situations Newton’s Laws work well enough.
But what will impulse drives do to Sir Isaac’s theories?
Impulse / inertial drives and Newton's Laws are just incompatible!
If the device is driven, by an internal force / reaction it does in effect become a self-propelled particle and the 1st Law becomes irrelevant,
The 3rd Law also becomes irrelevant, for the very same reason.
The 2nd Law may still stand with a bit of modification.
Not a lot left is there?
In light of this has anyone seen any theory, anywhere, which covers the properties governing self-propelled particles.
According to Einstein all externally accelerated particles are subject to the relativistic tendency for mass increase near the speed of light.
Consideration as far as I am aware, has only ever been given to mass which has been subjected to an external push.
Only assuming he is correct in this, should a self-propelled particle be affected in the same manner?
Sandy Kidd
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Eric James ----- - 29/04/2005 08:03:21
| | | Nitro,
I dissagree with the 90' reaction thing.
An observation of a precessing gyro shows a motion around the point of pressure in a plane 90 degrees from the direction of the applied pressure, but is it really a "reaction?"
Think about it. The applied pressure actually operates independently of the precession.
That is that if you do not consider the precessing motion, all of the reactionary motion is in line with the applied force.
In the case of one side of a gyro's axis resting on a support, the reaction is not apparent due to the equilibrium of forces acting upon it. Basically, the 1g of pressure to the axis is compensated by 1g of gravity pulling the apparatus down (hence, equilibrium). If even a small part of the reaction to the pressure went into the precessing gyro, gravity would always overwhelm the system and it would tilt off of the support.
In the case of applying 1g of pressure to an axis end in space (like by attaching a rocket to one axis end), all of the reaction is realized as a 1g acceleration for the entire apparatus (provided the gyro's rpm, mass and such are sufficient to maintain stability).
It appears that the precessing motion is completely independent of the linear action and reactionary motions.
Therefore, it can be concluded that, in this instance, the precessing motion must derive its apparent energy from another source.
I haven't seen any data, but I'm wondering if a precessing gyro's rpms fall off slightly. This would explain the apparent motion's energy source.
In other words, I suspect that the rotating gyro is transferring angular momentum into the precession's angular motion.
Eric
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Nitro Macmad - 29/04/2005 15:30:17
| | | Dear Eric,
To respond in order…….
You are welcome to disagree with the “90 deg. reaction thing” though I would find it hard to equate a gyro’s motion with “the opposite thing” even given that a pivot point is involved.
You think about it! Without the applied pressure there would be no precession.
If you do not consider precessing motion you are not talking about a gyro.
The precessional movement of the gyro IS the equilibrium of the force acting to change its axial angle.
A force acting at the remote end of a gyro’s axis to change its axial angle in space WILL cause precession while the assembly is being accelerated (due to the offset mass of the c of g of the gyro making the point of the applied force, a pivot point). This is precisely why gyros (and their solid state equals) are so wonderful for telling us our spatial orientation.
See above.
Your conclusion is ill founded. Precession in a gyro IS only powered by the application of a force (or, as is more likely, the resultant of many forces) acting to change its axial angle. The only input required is to overcome the bearing and skin friction. That a toy gyro droops is solely caused by the reverse torque of the pivot friction, acting to change the axial angle on the horizontal plane (i.e. between the Eifel tower and gyro frame), itself being precessed through 90 degs. this time slowly downwards.
A gyros rpm. only falls off (slightly) due to the (slightly) increased bearing load during precession NOT because some of its kinetic energy of spin is somehow taken to “drive” precession.
Your concluding suspicion is therefore, also ill founded.
Kind regards
NM
PS Sorry if my grumpiness has bled through into this response but it is my day off and this “sunny isle” is shrouded in mist and a drenching drizzle – why else would I be on the web in the daytime with so much to be done in the garden?
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Eric James ----- - 30/04/2005 06:48:54
| | | Nitro,
Goodness, sounds too complex for me. I like to keep it simple.
Actually, your statement of "an applied pressure" is incorrect.
Applying pressure off-center to an object is actually referred to as applied torque.
Torque is applicable to angular momentum as force is applicable to linear momentum.
If you applied the same pressure to the center point of the axis and (usually) consequently the center of mass, you'd get a linear acceleration for the whole assembly.
If you rested this point on a support, you'd get... well, you'd get nothing. No precession, no acceleration, no nothing. Equilibrium is preserved. The gyro just sits there and spins.
Therfore, it is the the off-center torque causing an angular response.
In the case of a precessing gyro you are attempting to spin the gyro in two axis, but are limiting one axis via the support. Therefore it realizes this second axis in the only way it can, with regard to this limiting factor, which is by spinning around the point of torque.
Eric
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Nitro MacMad - 30/04/2005 08:46:11
| | | Dear Eric,
Of course an applied torque is what we were talking (no pun intended but what the heck!) about.
To also nit pick - I did refer to “the application of a force (or, more likely, the resultant of many forces) acting to change its axial angle”. I only used the expression “applied pressure” as that was the term you used yourself and I thought that using your own terminology might help your learning.
I did try to keep it simple but the subject is counter intuitive and hard to get hold of without, at least some, effort. This is especially so because some of the terms we have taken for granted in “Newtonian”, like action and reaction, sit uneasily in “Gyrodynamic”.
Happy learning.
Kind regards
NM
PS Still raining – still grumpy.
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Eric James ----- - 30/04/2005 10:31:48
| | | Nitro,
Yes, you are right. I used "applied pressure." However, I used it as a general term for the purpose of erudition since it seems obvious that folks here confuse "linear force" with "angular torque."
I disagree that it is "counterintuitive" though. Things spin and spinning things follow Newton's laws. You just need to understand the relationships of the motions in question.
The easist to understand analogy is that a spinning mass works a lot like a linear mass in that both resist changes in speed and direction.
It's just that the spinning one is going 'round and 'round in the local vicinity.
Eric
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Victor Geere - 30/04/2005 17:49:55
| | | I have to agree with Eric here, in some way. The force that caused the gyroscope to spin is still present, and this is often ignored.
As I have said before and I will say it again: precession is not action nor reaction in terms of Newton's laws it is MOTION. Motion is the result of an unbalanced force. This motion will continue in direction of the NETT force until it is oposed by some other force. Action is you pushing the gyroscope and reaction is what the ground your standing on does to your feet, while you are pushing the gyroscope.
Galileo was correct, and when he realised that, he formulated a well defined theory. A theory that could be tested, retrofitted on existing observations and explains future observations. He didn't take cheap shots. The most important thing to note here is that Galileo was correct, a rare feat for those times, and an equally rare feat it seems, for today.
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Nitro MacMad - 06/05/2005 18:24:23
| | | Dear Victor
A body at motion under Newtonian is, like a body at rest, a body in equilibrium. Acceleration (or deceleration - or indeed deflection, which is rarely considered) of a body, not just the motion of a body, is the result of an unbalanced force you mention – not motion per se.
If I understand you and to use your analogy; action (assuming the classic gyro on its Eiffel tower) would be the gravitational force pushing down and reaction would be the Earth pushing up. The rotational motion of the gyro’s mass (and the surprising amount of extra non rotating mass you can attach) around the tower would seem to need to be, therefore, subtracted from the upward (or downward – to your choice) action to justify the rotational motion of this mass.
The spin speed of the gyro gives nothing to the precession. The rate of spin speed reduction only increases slightly because of the slightly increased bearing friction under the slightly increased load.
Kind regards
NM
PS Galileo wasn’t always correct (any more than I am). It would be interesting to know if we would have taken his side then, considering that taking his side was commercial (and perhaps even real) suicide. Are some of the views on this forum just history repeating itself, I wonder.
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Eric James ----- - 08/05/2005 08:06:59
| | | Nitro,
I'm aware you addressed your last post to Victor, but I thought I might butt in here (an American tradition you know).
You and victor are both right.
A gyro acts as a body in motion that tends to stay in motion, but it also requires force!
This is because all changes in velocity and direction are called "accelerations." Even slowing a body down is technically an acceleration.
Turning a body in motion is "accelerating in a new direction."
All acceleration requires force as a relation to F=ma.
In the case of angular momentum, this force is known as "centripetal force."
It's basically a passive force though so it's a bit hard to believe it is real.
Basically, in a gyro, this force is actually a result of the molecular bonds of the material consistently pulling the mass around and around rather than letting it go in the straight line it naturally "wants" to.
As far as precession is concerned, it is caused by a torque. Torque causes angular momentum. The gyro prevents the angular momentum from occuring in the plane of the torque since it is busy trying to maintain its own momentum which is contrary to the applied torque.
The gyro doesn't roll over because in its work to maintain gyro momentum, it causes an opposite and equal torque to be applied to the tower.
So, we basically have an impasse. An equilibrium of applied torques. So then, where is the precession coming from?
As I said, the gyro must perform work to maintain the opposite and eqaul torque. Torque (in this case) requires energy. The only available energy in the system is from the gyro itself.
Therefore, we can surmise that the energy for the precession comes from the gyro.
Where does the direction of the precession come from then?
In applying torque, the top of the gyro's mass "wants" to proceed downward and inward toward the tower, and the bottom "wants" to proceed upward and outward from the tower.
This basically causes the upward portion to want to move faster (as with a ballerina pulling in her arms) and the bottom to move slower. This difference in momentum is realized as a revolution of the gyro about the tower.
It's a small effect that is limited by the action of the gyro, therefore it is stable as long as the gyro can continue to provide the torque to the tower. When the gyro slows down too much, it no longer has the energy required to do this and it simply tumbles off.
At least this is MY theory, and I'm sticking to it!
Eric
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Nitro MacMad - 08/05/2005 20:35:40
| | | Dear Eric,
You have obviously given some thought to this but I think you have the wrong end of the stick in a few important points.
You are wrong to surmise that the “energy” for precession comes from the gyro giving up some of its kinetic energy of spin. Precession, weirdly, is merely the gyro’s rotational inertia causing the redirection of a force (torque) acting to change the axial angle.
The spin speed of the gyro is not reduced by precession. The kinetic energy of the energy input used to cause its original spin (there is a Vatican joke in there somewhere but I shall resist the temptation) is simply gradually lost to bearing and skin friction.
As I have explained in earlier postings the direction of precession, and indeed precession itself can be most clearly understood if the gyro is broken down to its fractional form:- the pendulum.
Try this: - slowly swing your arm and halfway through its swing turn yourself through 90 deg. while allowing your arm to continue its original direction of swing as would be caused by a pendulum’s inertia (this works best if you use your right arm and turn left, or you can do yourself an nasty injury). Mentally rebuild a whole wheel around this “pendulum” and you have a gyro precessing.
I don’t think that your analogy with a ballerina can be correct or, if you tilted her on her side you would expect her spin speed to increase. Probably be fun to try this though, especially if, as you say, her upward portion wants to go faster and her bottom slower. Who said British seaside humour was dead? Mortally wounded maybe, but not dead.
Kind regards
NM
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Eric James ----- - 09/05/2005 00:21:22
| | | Nitro,
Well, as I said "in this case" it requires work. The gyro doesn't give up momentum exactly to maintain the torque directly, but maintaining the torque requires the gyro to precess which is a form of work as there is movement of the mass.
It's kind of a chicken and egg thing.
Regardless, work is accomplished and this work must have a force with a source. Since it is apparent that the applied torque cannot be this source (remember it is demonstrating equilibrium), the source MUST come from somewhere else. The only other place it can be coming from is the gyro.
The work accomplished is negligible in comparrison with the available energy in the gyro, so it doesn't require a lot. However, every gyro under precession loses rpm faster than one not in precession, regardless of the quality of the bearings (sounds like a clue ro me).
Since the relation to force and work is very small, I believe folks have mistakenly believed that there is no transfer of angular momentum from the gyro to the precession.
You wrote:
"Precession, weirdly, is merely the gyro’s rotational inertia causing the redirection of a force (torque) acting to change the axial angle. "
I think we are agreeing, only from different viewpoints. I agree that the rotational inertia is causing the torque (I said something of the kind), but I also believe that the precession direction itself actually bleeds off tiny bits of momentum from the gyro (angular momentum transfer).
Your pendulum analogy demonstrates exactly what I said, "the bottom "wants" to go out and away."
Unfortunately, you cannot tilt a precessing pendulum on its side, unless you apply a steady lateral force to the pivot point (like gravity or acceleration). Then, all that happens is it'll precess relative to the angle of the new force.
Lastly, my description fits all known aspects of the laws of motion (as far as I can tell) and by Occum's razor the simplest explanation is the best, so I'll go with it until I find something better.
Eric
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Nitro MacMad - 09/05/2005 19:20:47
| | | Dear Eric,
Occum’s razor applies when you have more than one explanation that fits all the known facts. (in all other instances use a Wahl’s razor!)
That a gyro gives up the kinetic energy of its spin solely to bearing and air friction can more clearly be seen (where you say it would slow proportionally to its precessional force) in forced precession and, more especially, the trapped forced precession (what I can only term “kinetic precession”) of a gyro. Under these circumstances the deceleration (or increased load, if powered) of the gyro can be seen to be proportional to its increased bearing load, not to the increased load it is forced to precess.
As Nitro’s first law always applies; the frictional losses of the top of the Eiffel tower bearing can be observed as the speed of droop (you should excuse the expression!) of its precessional angle and that droop needs nothing from the gyros spin to drive it either.
One of the fundamental divergences of the “Gyro gang” and the “Newton gang” is that a gyro’s centre of mass appears to be at (or nearer than it should be to) its pivot point (the top of the Eiffel tower) not at its centre of mass. Several members of the “Newton gang” have said that this arrangement has been shown on air beds to rotate around its centre of mass, though we await sight of this. Have you any input on this?
Kind regards
NM
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Eric James ----- - 09/05/2005 23:50:16
| | | Nitro,
I'm an American! I have "input" on EVERYTHING! :)
Forced precession and "trapped forced" precession certainly increase the bearing load, but this is due to the counter torque of precession, so of course the bearing load and precesional torque go hand-in-hand and you cannot measure one separately from another in a precessional circumstance, and claim my theory is wrong.
You are simply stating that the bearing load increases (thus causing the gyro to slow faster) under higher precessional stresses. My theory agrees with that. This has little bearing (pun intended) on whether the precession takes angular momentum from the gyro. It simply states that bearing load causes it to slow down, not that precession doesn't take any momentum away too.
A real test would be to somehow load the bearings identically with and without precession and then measure the coast-down time and look for differences.
This would be a difficullt experiment to develop accurately enough to determine the difference between bearing load and angular momentum transfer since it would be difficult to simulate a torqued bearing load without actually spinning the gyro and forcing precession. You'd have to do it by applying external pressure to the axles with a wheel and a load meter and....
By droop, do you mean the initial drop after the outer shaft's support is removed? This is caused by the slack in the system (loose bearings and whatnot) and system flexibility under torque.
I would think that the pivot friction would actually act against the droop as it might be a force acting on the pivot point in such a way as to induce a slightly upward precession force. This might actually serve to extend the time that the gyro precesses.
The center of mass thing makes little sense to me. The center of mass is the center of mass. On the air table, the center would have to include the tower, so pivoting at the center of the gyro wouldn't make sense, unless the tower was counter-balanced on the other side of the gyro.
This should be a clue to you that your observations are sort of correct (in a way) beacause the mass of the system includes the tower. In other words, the center of mass is actually somewhere between the center of the tower and and the center of the gyro.
Does it always include all of the mass of the tower? On the air table it must. Therefore in space it must too. Attached to the earth? No, this is because the earth becomes part of the mass too! You'd have to include it!
So, you can count it as a being a virtually infinite mass, or you can ignore it. Your choice.
In the first, the center of mass is basically the top of the tower. In the latter it is going to be the center of the gyro. It's all relative you know.
Please note: Everything above is all just out of my head and needs empirical verification.
Eric
P.S. We are experiencing heavy thunder showers today, and yet I'm not grumpy! Lots of hail too!
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Sandy Kidd - 10/05/2005 08:02:33
| | | Eric, NM & other parties.
You guys were doing a wonderful job here, but I do think you are making things a lot more involved and complicated than they really are, however Eric you made a point in relation to angular momentum transfer in relation to vertical fulcrum bearing load.
Sandy’s input for what it’s worth.
I think Eric you will find that there is no angular momentum transfer to the fulcrum, (effectively) only gyroscopic rest mass is transferred.
Don’t know how you could transfer angular momentum to the fulcrum anyway, which is effectively just a point of contact, but if you find out I’d like to share the patent with you.
It can be seen therefore that as the mass is transferred it can no longer be accelerated and the angular momentum is consequently reduced, eventually to zero.
Only the rest mass (or part of the rest mass) of the gyroscope will appear to act vertically downwards through the fulcrum.
Sandy.
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Eric James ----- - 10/05/2005 08:55:29
| | | Sandy,
Hmm, then you might ask yourself why it needs to precess at all? Why doesn't it just rest there without moving?
Or, if all the forces are equal and all the directions are self-canceling, why does it precess one way and not the other?
Eric
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Sandy Kidd - 10/05/2005 12:34:53
| | | Eric,
You are obviously discussing passive systems.
You are putting the cart before the horse.
It is all only balanced when it is standing still, in other words supported.
Unsupported, how do you stop it moving Eric?
Sandy
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Nitro MacMad - 10/05/2005 19:39:43
| | | Dear Eric,
It doesn’t “need” to do anything it’s just what the thing do. It wonderfully converts a force (acting to change….etc. etc) not, as would be the case in anything but a precessing gyro, into an acceleration; but into a SPEED. Increase the force and, with no delay waiting for acceleration to take place, a greater precessional SPEED happens instantly.
A precessing gyro is the close mechanical equivalent of an operational amplifier with full negative feedback (a voltage follower) and what you ask is like asking how an op. amp. knows how much voltage to feed back to clamp a mixture of voltages at its output – it’s what the thing do!
Axial change resulting from the first applied force produces a further precessional force that is itself precessed and so on and on and so…… a speed, not an acceleration of the gyros mass results.
What did Leonardo say? Fools it is all laid out for you to see…… It’s sunny so I’m going out in the garden now before they come and take my crayons off me.
Kind regards
NM
PS. Nice sunny weekend here. My Queen visited me – well the Island really – to commemorate the passing of sixty years since the last bumper year for German tourists. I joke (badly as usual – Irene says I make Basil Faulty seem normal) I count many Germans as friends – and anyway at least they joined the war early on. What! Me, have a dig at the Yanks? Surely not!
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Eric James ----- - 11/05/2005 01:35:37
| | | Nitro,
Better late than never, eh? You'd be speaking german if not for folks like my Mom and Dad (that's Mum and Pops to you Brits).
Anyway, you and Sandy are thinking a bit two-dimensionally. So I will begin to enlighten you (stretching out my arms like Charlton Heston in the 10 commandments).
"Behold and go forth to the latest question in the forum, which I am about to ask..."
Eric
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