system
Given the following post, respond as if you're commenting on Reddit:
human
If you were to hypothetically manage to turn all the lights out in a major city (ex. New York City) how long would it take to see the stars? Or would it be instantaneous?

And what would cause the delay, if there was one?
gpt
It's practically instantaneous.

You may get a little delay from clouds reflecting the light for a fraction of a second longer than if there was no clouds or atmospheric conditions which reflect light back.

Then you'd have to wait for your eyes to adapt to the darker conditions. This is the part which you'd notice without some equipment.