Naked Science Forum
General Science => General Science => Topic started by: Jon Francis on 08/08/2010 21:21:19
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Why do gyroscopes resist the effect of gravity?
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Hi Jon. Gyroscopes do not "resist gravity" although the behaviour of a precessing gyroscope moving slowly around a pedestal may look unnatural. In fact they completely obey Newtonian physics. All the weight of the gyroscope is transferred through the pedestal to the base.
Professor Laithwaite, in the 1970s I think) carried out some poorly designed experiments which claimed to show otherwise, however these were later discredited.
However, there can be complex relativistic effects to do with gravity related to large spinning masses. The effects are still subject of some speculation and are under investigation with specific orbiting satellites designed to detect the very small effect. See Gravito-magnetics for more detail (nothing to do with magnetism but called this by analogy with electro-magnetics).
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Seems to me more a matter of inertia and the stability of a spinning mass than it does gravity...but then again, in my head, gravity and inertia are related much like electricity and magnetism.
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- I posted this thread on Twitter !
Regards
Charles
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Gyroscopes defying gravity is a myth, and EASILY explained. Without going into the formulae for momentum it's as such.
Visualize a non-spinning gyroscope falling. It doesn't fall straight down because it's supported at one end of the axle. It will fall downward in a sort of arc until the centre of gravity is below the centre of support. Its basically 'tipping over' but 90 degrees from vertical
But a gyroscope resists changing directions. It's not resisting gravity. It's resisting the arcing motion reuired of tipping. The fact that it's horizontal to the ground (yet supported at one end) has nothing to do with it. Your finger is supporting it's weight, and it doesn't want to change its attitude until the rotational rate is slow enough that angular momentum is insuffient to "hold it" in possition.
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They don't. If you drop a gyroscope it falls at exactly the same rate as everything else.
However the conservation of angular momentum means the weight of a spinning gyroscope is insufficient to alter the direction of the axis of spin quickly, so it takes a long time to tilt.
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have a look at this video of a cube with 3 gyros. most impressive .
http://arteinsky.blogspot.co.il/2014/01/a-magic-gravity-defying-cube-that-can.html
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Gyroscopic precession explained (http://www.youtube.com/watch?v=ty9QSiVC2g0).
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Professor Laithewait, during his presentation of the Royal Institute Lectures (I forget which year) did some experiments with gyro’s, notably one consisting of a wheel rotating on the end of a static shaft. He claimed that the wheel had a mass of 40 pounds (18 kilograms in proper units), and the shaft seemed to be about a metre long. While the wheel was static he could only lift it by grasping the shaft with one hand at each end.
The experiment consisted of a boy from the audience being asked to sit on a chair which could freely rotate in the horizontal plane. The wheel was caused to rotate at high speed, the boy was given the shaft to hold horizontally. Needless to say, the weight of the spinning wheel caused the boy’s chair to rotate (precess), to the amusement of the audience.
The point is that the boy was able to support the weight of 18 kg by holding the shaft with one hand at the end furthest from the wheel with little difficulty, while the chair was rotating under precession. On the face of it this would require a torque of around 180 Nm applied by the boy to the end of the shaft. It’s tempting for the uninitiated like me to believe that the wheel (gyro) had become lighter.
I’m sure that no laws of physics were broken, but I have yet to see an explanation that I understand of this phenomenon.
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Exactly! The demonisation of Eric Laithwaite by the 'science faculty' after his filmed gyroscope demonstrations were nothing short of disgraceful and shameful.
Science has yet to explain how a frail elderly man can lift a 42lbs weight above his head when it is spinning, but cannot do so when it is stationary with relation to its axis.
It's as if the whole science community keeps saying 'the earth is flat!' ad-infinitum.
Some people have been aware of this amazing and inexplicable (under Newtonian physics) phenomenon for years, however, the best that the idiots can contribute is 'His theory was later disproved'
Laithwaite later agreed that his observations did not contradict Newtonian physics, but the 'scientific community' did not relent at all, and continued deriding him (the lauded and super-intelligent inventor of the linear motor no less)
NASA then hired him to develop his applications of gyoscopy for use in space thrust without rockets, however, he died before starting work for NASA.
The shameful way he was treated, and the refusal of 'science' to recogise this phenomenon was a certain contributing factor to his premature death.
Someone please explain how a frail man can do the above? AND DON'T just say 'he was disproved'!!
The experiment works, and is on film and there for all to see! (except contemporary science of course) a phenomenon similar to the idiots who are saying; There are no Nazis in government in Ukraine' Both are just liars, and both have vested interests in denial.
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While the wheel was static he could only lift it by grasping the shaft with one hand at each end.
...a boy from the audience being asked to sit on a chair ... The wheel was caused to rotate at high speed, the boy was given the shaft to hold horizontally. The point is that the boy was able to support the weight of 18 kg by holding the shaft with one hand at the end furthest from the wheel with little difficulty
It seems that this discussion is about whether you can hold up a weight at the end of a meter-long pole with one hand, or if you need two hands.
Normally it is impossible to lift with one hand, because your hand can't get enough torque. You need two hands.
But when the gyroscope is spinning (and the chair is turning), you don't need to apply a torque with your hand, but merely to support it vertically. This is much easier, and can be done with one hand.
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Laithwaite later agreed that his observations did not contradict Newtonian physics, but the 'scientific community' did not relent at all, and continued deriding him
Personally, I think he sniffed too much mercury; one of the uses of linear motors is for pumping mercury, and there's videos of him doing that.
(the lauded and super-intelligent inventor of the linear motor no less)
NASA then hired him to develop his applications of gyoscopy for use in space thrust without rockets, however, he died before starting work for NASA.
That's not what happened. They hired him to work on linear motors for space launch.
The shameful way he was treated, and the refusal of 'science' to recogise this phenomenon was a certain contributing factor to his premature death.
He was 76. That's pretty much average.