How does the doppler effect a beluga whale determine whether a fish is going
away from it or toward it

If the Beluga Whale makes a sound that hits a fish moving towards it, the frequency of the sound that the Beluga gets back will be increased (higher pitch). If the fish was moving away when the sound hit it, the sound will come back to the whale in a lower frequency (lower pitch). So depending on what sound the whale hears reflected off the fish, it can tell if the fish is moving away or closer.

The investiture controversy began as a power struggle between pope gregory vii (1072–85) and henry iv, holy roman emperor (1056–1106).[2] a brief but significant struggle over investiture also occurred between henry i of england and pope paschal ii in the years 1103 to 1107, and the issue played a minor role in the struggles between church and state in france, as well.by undercutting the imperial power established by the salian emperors, the controversy led to nearly 50 years of civil war in germany, and the triumph of the great dukes and abbots. imperial power was finally re-established under the hohenstaufen dynasty. historian norman cantor:

They immigrated for religious freedom