system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 how can you cool atoms with lasers?

Give me your best analogies!
gpt
Let's say you have a robot with an electric motor connected to an array of directional microphones, which will accelerate in the opposite direction whenever it hears a very specific note, say a C minor. The rest of the time it's just moving around randomly but at a constant speed.

Now you set up speakers all around this robot playing a C minor that's just a *tiny* bit out of tune. The sounds are a tiny bit too deep, less than 1% but that's still enough your robot won't react to it. 

If the robot is moving towards a speaker, though, at the same less than 1% of the speed of sound, that causes it to "drive into" the soundwaves giving the same effect as when an ambulance drives past you, making it hear the off-key C minor as being exactly on key, which causes it to try to go in the opposite direction, slowing down. 

Atoms only react to specific frequencies, colours, of light, same as how the robot only reacts to specific notes, and the frequency of light gets shifted by moving towards it or away from it same as sound.