Gyroscopes as navigational devices

[beethoven'smahomeboy]

In the context of Newtonian mechanics, why are gyroscopes good navigational instruments? What is the best shape for a gyroscope?

 

[shyboy]

Gyroscopes try to keep their rotational moment, so if you put a gyroscope in a special frame, it will try to keep the initial axis of rotation no matter what happens with frame. Thus you can track you relative movement by using an onboard system. So you do not need any external references, like GPS satellites. That is why gyroscopes are used in ICBM and tanks.
Bycicle weels are gyroscopesto, and they try to stabilize you bike on a straight line.
good link: http://hyperphysics.phy-astr.gsu.edu/hbase/gyr.html

 

[skeptic]

Although inertial navigation devices make use of the fixed orientation of a gyroscope, the more traditional method is to exploit the fact that a properly counterweighted gyroscope will tend to align itself with the Earth's axis.