I know the vector equation that relates torque to moment of inertia and angular momentum. What I want to know is what physical mechanisms actually occur to keep the gyroscope from falling. Where is the upward force coming from and how, mechanistically, does this get produced?

  • $\begingroup$ @dj_mummy Thanks..but I can afford that book and the overall level is beyond me. Can you provide the highlights? Again, I don't want the math, I want the actual mechanisms. $\endgroup$ – user31580 Feb 12 '14 at 5:29
  • $\begingroup$ have a look at this www2.eng.cam.ac.uk/~hemh/gyroscopes/onetofour.html $\endgroup$ – anna v Feb 12 '14 at 5:36
  • $\begingroup$ @annav this reference appeals to angular momentum. I'm looking for a description at the level of internal forces that describes where the force comes from, not why its generated. DumpsterDoofus' answer was along the right lines. $\endgroup$ – user31580 Feb 12 '14 at 5:51
  • $\begingroup$ If you like this question you may also enjoy reading this Phys.SE post. $\endgroup$ – Qmechanic Mar 14 '14 at 15:09

Since you don't want a math description, but rather a physical intuition, I'll attempt to give one.

The opposing force comes from the fact that when you try to rotate the gyroscope, you are attempting to redirect the path of the material in the spinning ring. Imagining the spinning ring as a discretized collection of point particles in motion, you are essentially trying to push on these moving point particles to divert their path.

When you punch a baseball to divert its path, you feel a force against your hand which opposes your attempt to divert its path. The exact same physical/tactile intuition applies to the gyroscope, once you view the interior ring as a collection of moving point particles whose motion you're trying to divert.

A faster moving baseball requires more force to deflect its path by a certain angle; similarly, the faster a gyroscope ring rotates, the more effectively the assembly will resist your attempts to rotate it.

  • $\begingroup$ Thanks. So if we have a gyroscope supported on one end and place a weight on the other end while it's spinning, how does that resistance keep it from tipping over? there is nothing for the gyroscope to push back on. Is there always some amount of nutation (in addition to precession) that keeps the gyroscope in a dynamically stable trajectory (albeit ocillatory at a small enough scale?) $\endgroup$ – user31580 Feb 12 '14 at 5:46

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