G:

geocentric: “earth-centered:” the model of the solar system before Copernicus and still used by most astrologers as their basis for interpretation.

gorgon: a female monster and protective deity with hair of venomous snakes who turned anyone who looked upon her to stone. The three gorgons were Medusa (the only mortal one, Athena turned her into a gorgon because of her vanity: she said she was more beautiful than Athena herself; killed by Perseus), Stheno, and Euryale.

graben: a depressed block of land bordered by parallel faults; a valley with distinct scarps on either side. Grabens often occur alongside horsts, raised areas next to the graben’s depression; both indicate tensional forces and crustal stretching.

grand cross: four planets in square aspect, including two oppositions (a complete fourth harmonic syndrome). This is an intense and often stressful structure needing a focus for its considerable energy into specific purposes and constructive action. Usually a grand cross occurs all in one quadruplicity: if in cardinal signs, the outlet for the energy is action; in fixed signs, the outlet is emotional and/or surrendering self will; in mutable signs, being able to see all sides leads to indecisiveness and diffusion of energy—an adjustment in thinking habits is necessary.

grand trine: three planets each in trine to the other two; a complete third harmonic syndrome; perfect equilibrium and balance denoting great talent, ease or harmony, usually all in one element (earth, air, fire, or water); often a static, inert structure not promoting the growth and evolution that confronting the difficulties of the hard aspects does; for this reason the ancients used to think of the grand trine as evil or malefic (see kite and minor grand trine). An exact grand trine (orbs<1°) or with an opposition or square is more dynamic, and has more energy available for change.

gyroscope (see page 42): a device invented in 1852 by the French experimental physicist Leon Foucault (1819-1868) as part of a two-pronged investigation of the rotation of the earth. The better-known demonstration of the Foucault pendulum showed that the plane of rotation of a freely swinging pendulum rotated with a period that depends on the latitude of its location. His gyroscope was a rapidly rotating disk with a heavy rim, mounted in low-friction gimbals. As the earth rotated beneath the gyroscope, it would maintain its orientation in space. This proved to be hard to do in practice because frictional forces brought the system to rest before the effect could be observed.