Assuming what you mean to ask is what are the scientific principles demonstrated by a lava lamp, here is the text of a comment I entered to answer similar questions on the homemade lava lamp activity (linked below):
This project demonstrates a number of different principles. The first is is that the molecules of water do not mix with the molecules of oil no matter how much you shake the bottle. The food coloring only mixes with the water which is why it doesn't color the oil. The second principle demonstrated is density. Water is denser (heavier) than oil which is why the water sinks to the bottom when you pour it in. It's also why oil floats on top of the water if a ship spills oil in the ocean.
Alka-Seltzer reacts with the water to create tiny bubbles of carbon dioxide gas. The bubbles attach themselves to blobs of colored water and cause them to float upwards. When the bubbles reach the surface and pop the color blobs sink back to the bottom.
I think it will look very pretty when this project glows. And the water with the oil will be half apart. I think this is the hypothesis. I hope it worked out with my project. I got a 100% on my last project in 2014.