Glow in the Dark: A Simple Experiment with Everyday Fruits

Learn how a potato or unripe banana can glow faintly in the dark! By exposing the chlorophyll in their peels to bright light, you can witness phosphorescence, where stored light energy is gradually released—an easy and intriguing way to explore luminescence.

What you need:

1. A potato or an unripe banana with a slightly greenish peel
2. A bright lamp (e.g., a desk lamp) or sunlight
3. A dark room

Here’s how:

1. Place the potato or banana under a very bright lamp or in direct sunlight for about 2–5 minutes.
2. Bring it into an absolutely dark room.
3. Observe carefully: You might see a faint green glow.

What happens?
The potato or banana emits a weak light for a short time.

Why does this happen?
There are remnants of chlorophyll in the peel that store light and release it again slowly. This is called phosphorescence—a form of luminescence in which energy is emitted as light with a delay.