“He only is my rock and my salvation: he is my defence; I shall not be moved.”
Lewis Carroll’s nonsense poem Jabberwocky, in Alice through the Looking Glass, begins thus:
Twas bryllyg, and the slythy toves
Did gyre and gymble in the wabe
Later in the story, Humpty Dumpty explains that the verb gyre means that these slythy toves were rotating, like a gyroscope.
Gyroscopes used to be sold as children’s toys. However, I remember TV scientist Dr. Eric Laithwaite demonstrating the power of gyroscopes in his Royal Institution Christmas Lectures on BBC television in 1974. It was fascinating to see that the direction of the spin axis remained where it had been placed, even as the outer mounting moved around. For this reason, gyroscopes have been used for directional navigation. So long as the original axial rotation is placed accurately, its spin will enable accurate navigation.
Modern gyroscopes do not use large physical wheels. Cellphones contain microelectromechanical sensors which measure changes in forces on small oscillating masses. A newer idea, using optical gyroscopes, contains no moving parts. An article on the use of such optical gyroscopes describes the Sagnac Effect, which “relies on detecting a difference between the two beams as they travel in opposite directions”.
The article describes work by scientists at the California Institute of Technology, which may allow for gyroscopes the size of a grain of rice.
Such immovability is used in Scripture as a metaphor for the faithfulness of God and also for the sort of fixity of faith to which Christians should aspire.