Question

answer the question below. view the rubric linked above for help if needed.
a group of astronomers in chile analyzed the motion of 133 galaxies. they calculate that two are moving toward earth, and the rest are receding. does this finding imply that the big bang theory should be revised? why or why not? use details to support your answer.

Explanation:

The Big Bang theory posits that the universe is expanding, with most galaxies receding from us due to this expansion. However, local gravitational interactions between galaxies (like galaxy clusters or groups) can cause some galaxies to move toward each other (and thus toward Earth in this case) even as the overall cosmic expansion occurs. Out of 133 galaxies, only 2 are moving toward Earth, and the vast majority are receding. This small number of galaxies moving toward Earth is consistent with local gravitational effects (e.g., a galaxy might be part of a cluster where gravitational attraction from a nearby massive galaxy pulls it toward that cluster, which could be in our direction) while the overall trend of most galaxies receding supports the expansion from the Big Bang. So this finding does not imply the Big Bang theory needs revision because the theory allows for local deviations from the general expansion due to gravity, and the dominant trend here is still galaxies receding.

Answer:

This finding does not imply the Big Bang theory should be revised. The Big Bang theory states the universe is expanding, so most galaxies recede from Earth. The 2 galaxies moving toward Earth can be explained by local gravitational interactions (e.g., within galaxy clusters/groups) that override cosmic expansion locally. The vast majority (131 out of 133) receding aligns with the theory’s prediction of universal expansion, so the local exceptions don’t contradict the overall model.