This abbreviated Latin phrase means to make things up on the fly, off the cuff-to improvise. In Latin, it literally means according to pleasure. To see the full Latin
phrase, add the letters i-t-u-m to the end of the second word.

The big bang theory suggests that the universe is constantly expanding and that stars, galaxies and other entities are moving away from each other. if there were a galaxy moving closer to earth then that would contradict the big bang theory since the entities should be moving away from earth and from each other.