system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:How do boomerangs work?
gpt
When you throw a boomerang, the side that is furthest away from the hand throwing it would move faster than the side closer to the hand. This difference in speed causes the boomerang to spin. 

The difference in speed also would cause one side of the boomerang to have more lift than the other, resulting in the boomerang having it's course altered gradually to one direction (either left or right) with each rotation. The boomerang would keeping on following that one direction until it makes a full round and return to the person who threw it.