A spinning wheel or disc in which the axis of rotation is free to assume any orientation by itself. When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, according to the conservation of angular momentum. These devices are used for measuring or maintaining orientation and angular velocity.
Questions tagged [gyroscopes]
312 questions
33
votes
7 answers
Why don't spinning tops fall over?
One topic which was covered in university, but which I never understood, is how a spinning top "magically" resists the force of gravity. The conservation of energy explanations make sense, but I don't believe that they provide as much insight as a…
Casebash
- 2,804
33
votes
3 answers
How do we stabilise satellites so precisely?
Look at the Hubble Ultra Deep Field photo. The stars in it are on the order of 1 arcsecond across. To an order of magnitude, this is $10^{-6}$ radians in a $10\text m$ telescope which was held steady for $10^6$ seconds.
In other words, the velocity…
spraff
- 5,256
27
votes
6 answers
Can a car steer on a frictionless surface?
Do the front tires of a car act like gyroscopes, such that a car could steer on a frictionless surface?
Geremia
- 2,191
22
votes
5 answers
Why does a spinning top get back upright when knocked?
I have observed that, a spinning top, when toppled by knocking it with finger, becomes almost upright again (with negligible precessional motion), instead of undergoing precession while being heavily leaned.
I cannot find which force produces the…
Archisman Panigrahi
- 3,350
20
votes
7 answers
What determines the direction of precession of a gyroscope?
I understand how torque mathematically causes a change to the direction of angular momentum, thus precessing the gyroscope.
However, the direction, either clockwise or counterclockwise, of this precession seems to me a bit arbitrary beyond…
high schooler
- 201
17
votes
4 answers
Why are spacecraft made to "spin" after launch?
At some point after launch, usually just before or after separation from the last booster stage, spacecraft are often made to "spin" (about the axis of their trajectory)? See e.g this You Tube video. What is the reason for this spin?
orome
- 5,209
15
votes
3 answers
Spinning gyroscope loses weight?
I ran two tests with a toy gyroscope spinning on a weighing scale that is accurate to $1$mg.
The scale was reset to zero before the tests. The gyroscope was flipped over between test $1$ and test $2$. Each test consisted of $100$ weight readings…
John Eastmond
- 6,111
14
votes
9 answers
How do you explain spinning tops to a nine year old?
Why don't spinning tops fall over? (The young scientist version)
My nine year old son asked me this very question when playing with his "Battle Strikers" set. Having studied Physics myself, I am very keen to encourage him to take an interest in…
JHH
- 197
14
votes
1 answer
What makes a wrist-energized gyroscope rotate faster?
I'm considering a wrist-energized gyroscope, shown below (after my daughter let it fall and it broke open). That one was sold as Roller Ball, but variants are known as Powerball, DynaBee, Dynaball, Dyna-Flex, Wrist Ball, NSD Spinner..
There are…
fgrieu
- 447
12
votes
2 answers
Would a double gyroscope still have gyroscopic properties?
Imagine you have a gyroscope that has two spinning parts, one on top of the other. When you pull the string, the two halves spin in opposite directions. Would this cancel out the gyroscopic properties, or double them?
Jason Chen
- 369
10
votes
2 answers
What's the deal with the gyroscope?
In this article ("The problem with physics", Tony Rothman, ABC science) the author says in the 5$^\textrm{th}$ paragraph:
For example, one needs only first-semester equations to describe reasonably well the behaviour of a gyroscope; engineers can…
Joebevo
- 2,291
10
votes
3 answers
Magnet gyroscopic force spin
I was wondering whether a magnet exerts any measurable gyroscopic effects. I understand that magnetism is caused by alignment of spins of electrons which have angular momentum. (I realise that that they do not actually spin though), so it seems that…
user63826
8
votes
2 answers
With respect to what does a Gyroscope maintain its orientation?
Assume ideal conditions, no friction, no energy loss in any form.
Just an ideal gyro, in ideal conditions, spun into rotation and left alone. And placed somewhere on earth.
From what I've read so far, it should maintain its orientation, with…
user238194
- 126
8
votes
1 answer
Gimbal Lock: why is it a problem?
I was watching the video Gimble Lock - Explained, by videodumper, about the gimbal lock problem. I understood that during rotations it could happen that one DOF disappear. Looking at the middle part of the video (min 3.22) can be seen that two…
Enrico123
- 81
8
votes
2 answers
how can you keep a gyroscope turning?
I'm trying to understand how do gyroscopes and cmgs used for navigating keep on spinning even though there's friction. Any engine/pushing mechanism I can think of will restrict the gyro's rotor to a fixed direction and defeat the purpose... how is…
ihadanny
- 215