also, the blank a galaxy was, the faster it was moving. what is blank?
The missing word in the sentence is "farther".
In this context, the word that fills the blank is "farther." The statement implies that the farther a galaxy was, the faster it was moving.
To determine what "blank" refers to in the statement "the blank a galaxy was, the faster it was moving," we need to analyze the context and available information.
Given the relationship between the blank and the speed of a galaxy, it is likely referring to a specific characteristic or property of a galaxy that affects its motion. One such characteristic that fits this scenario is the "distance" of a galaxy.
According to observations in cosmology, galaxies tend to move away from each other as the universe expands. This phenomenon is known as the "Hubble expansion" or "Hubble flow." The speed at which a galaxy is moving away from us (recession velocity) is directly proportional to its distance from our location. This relationship is described by Hubble's Law, which states that v = H0 × D, where v is the recession velocity, H0 is the Hubble constant (representing the rate of expansion), and D is the distance to the galaxy.
As per Hubble's Law, the blank in the statement could be "distance." In this context, the farther a galaxy is from us (or any observer), the faster it appears to be moving away.
Therefore, in the statement "the blank a galaxy was, the faster it was moving," we can fill in the blank with "distance." The farther a galaxy is, the faster it is moving away from us.