system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does boiling water stop rolling when you stir it?
gpt
When water is at a rolling boil, the hottest water near the heat source is becoming gaseous and forming bubbles.  

When you stir, you are mixing the cooler water from the rest of the pot in with the very hot water, cooling it down and preventing the formation of steam.