Precession is
A) when the elliptical orbits of planets slip forward with each revolution.
B) the process of planetary evolution.
C) the stage before planets stabilize into a stationary orbit.
D) the wobbling of a planet's axis of rotation.
Question 2
Light is without mass, so how can gravity have an effect on light?
A) The space through which the light passes is curved.
B) Photons actually have a very small mass, so gravity does have an effect on them.
C) When light interacts with particles, it loses some energy, and thus takes on some mass.
D) Gravity has no effect on light.