Hubble's law describes the empirical relationship linking the distance of an astronomical object, such as a galaxy, to its recessional velocity. This observed linear relationship dictates that the farther away a galaxy is, the faster it appears to move away from the observer. This correlation is a primary piece of evidence supporting the concept that the universe is expanding uniformly. The effect is not due to the galaxies moving through space, but rather the fabric of spacetime itself expanding, stretching the distances between all unbound masses. This observation is fundamental to determining the age and ultimate fate of the cosmos.