DIY Lava Lamp Bottle Experiment

A clean plastic bottle

Water

Vegetable oil

Food coloring

Effervescent tablets (Alka-Seltzer or generic)

Fill the bottle one-quarter full with water and add food coloring.

Fill the rest with vegetable oil, leaving space at the top. Let the layers separate.

Break an effervescent tablet into pieces.

Drop one piece in and watch — colored blobs of water rise up through the oil and float back down.

The effect looks exactly like a real lava lamp.

Drop another piece when the action slows. You can reactivate it endlessly.

Try it in a dark room with a flashlight underneath for a dramatic glow.

The science: the tablet releases carbon dioxide gas, which attaches to water droplets and carries them up through the oil. When the gas escapes at the top, the water sinks back down. Density + gas physics.

This works with any color, but red and blue look the most dramatic against the yellow oil.

Use a clear bottle for the best viewing — the see-through effect is essential.

The bottle can be reused endlessly. Just add another tablet whenever you want the show to restart.

Hold a phone flashlight under the bottle in a dark room for a genuinely stunning light show.