How do those glow-in-the-dark light sticks work?

Summertime is glow stick (or light stick) season—it’s fun to wave them around at night, at parties, during those Fourth of July celebrations, at the campground, etc. But how do those little day-glo sticks glow (at night) without a battery or a bulb?

Glow Stick Science Experiment

How Glow Stick Colors Work

Glow stick lanterns

How does 'glow in the dark' work? - BBC Science Focus Magazine

Glow stick - Wikipedia

Can you recharge a glow stick? - Glowtopia

The Science Of Glow Sticks

Glow stick - Wikipedia

How to Make Glowing Jars (Using Glow Sticks) - Crafty Morning