A hypothetical particle postulated to be the quantum of gravitational interaction and presumed to have an indefinitely long lifetime, zero electric charge, and zero rest mass.
引力微子一种假想粒子，被假定为引力相互作用的量子，并被推测为具有无限长寿命、零电荷和零静止质量
A mare on the moon having rock of greater density than that of the surrounding area, thus exerting a slightly higher gravitational force.
