Gravity affects weight, it does not affect mass. Masses always remain the same. Newton's Second Law of Motion: Force = mass x acceleration The acceleration of an object is: a) directly proportional to the net force acting on the object. ... c) inversely proportional to the mass of the object.
Refraction of waves involves a change in the direction of waves as they pass from one medium to another. Refraction, or the bending of the path of the waves, is accompanied by a change in speed and wavelength of the waves.