Display of Diwali-fireworks in our Homemade Lava Lamp!

by Rashmie Jaaju on October 17, 2011 · 33 comments

in Science Fun

Science experiments can be such amazing tools for play for young children, I can't write enough how much we love them!

Having said that, when we do play with one or the other science experiment, I sometimes reflect back – with a tinge of heartbreak – on my own school days in the physics and science lab. I wish those experiments in the labs were conducted with a spirit of play and wonder for us to be able to enjoy the learning to the hilt rather than look upon them as classes of grave importance where we ought to follow the experiment to the 'T' or we would end up with nothing relevant (really?) to write about in the inference column!

This limitation and pressure never allowed me to enjoy those 45 minutes in the science lab. For, the only objective in my mind was to do the experiment the 'right' way to be able to get the result that the teacher and the text book mentioned we should get.

But here, in our home-school, there's no such pressure. There's no right or wrong way. There will be failed experiments. The experiments will turn out one or the other way. What matters is the fun of exploring and uncovering.

Last week, we did one such science experiment that goes so well with the festive spirit we are in these days. It is a perfect way to touch upon the concept of liquids, their density and chemical reaction.

It is a mini fireworks of sorts – albeit – without fire and in bottles!

The pictures, mind you, are not 10 percent as gorgeous as the actual scene. Yes, this experiment created the most mesmerizing sight that a child can ever behold. Sadly, I had to use my point-and-shoot camera rather than my DSLR as it was discharged. That's another reason the pictures are not doing justice.

But then, truth be told, no camera could have ever captured the colourful, magical phenomena that this experiment led to.

You have to do it to believe it! As simple as that. (smiles)

The process is super cheap and easy to set up. Not much mess either.

This is all we needed:

  • Four 1 litre bottles. (you can do this in just 1 bottle if you wish)
  • 1 Funnel
  • 1 litre oil (for the 4 bottles. Less, if you use only 1 bottle)
  • Water
  • Food Colour 
  • Effervescent tablets like – Histac or Pepfiz (available in India) or Alka-Seltzer (if you're in U.S.)

How to?

We placed the three bottles on our dining table and filled each with 1/3 water. Next, with the help of the funnel, Pari poured oil into each bottle – about 1 cm from the rim.

Once this was done, she added drops of different colours toe ach. I had her use different 'types' of color to see how each will react and which one will produce best results. She added green food colour to one, blue tempera paint to another, orange tempera paint to the third (also added few drops of red glass colour).

See the pictures and read on to know which colour worked best.

Right from how the color 'glides' through the oil before it reaches water to how it reacts later – food colour is much more impactful compared to tempera paint and glass colour. 

Finally, I gave her the effervescent tablet after breaking them into smaller pieces.

This was the WOW moment, when an explosion took place inside the bottle and the color drops collided with water to rise above the surface of the oil. In the process, firework-like reaction takes place with the glistening balls of colour wrapped in water and oil go around vigorously inside the bottle. 

So, what really happens is – oil and water don't mix with each other. Oil being less dense, floats on water. When the effervescent tablet is introduced, it reacts with water to release carbon dioxide gas. This gas is less dense compared to oil, so it wants to rise above the oil surface. In the process, it takes some water along with it. When the gas bubbles reach the oil surface, they pop and the water falls back through the oil. Read a detailed explanation complete with chemical equation etc. over here.

The whole reaction causes lot of agitation and momement turning it into a brilliant display of light and colour – so Diwali-like!

It's breathtaking! As she went on adding more tablets, the explosion of colour continues. It's nothing less than a miniature version of fireworks. Except that we didn't need any fire to create this show!

Before long, Avie comes back from office and is immediately sucked in, in this brilliant display. He recorded the experiment.

Pari went on adding the effervescent tablets till they were all gone. She wanted to do some more. So, I brought in the 'ENO' – the anti-acidity powder that is so common in India not just for indigestion and flatulence but also to make instant-idlis or instant Dhoklas etc!

I really recommend you to try this lava lamp experiment this Diwali or Christmas!

For more amazing science experiments, refer to these wonderful resources:


I would love to know any other useful resource to do science-based activities with kids. Please share if you know if any. 

Or, feel free to link to any science experiment that you did with your child.