We are the proud owners of a lava zebra and hot pink lava lamp. Well, technically one of our kids is the proud owner of this little contraption. It can be mesmerizing and has created the question on occasion, How Does a Lava Lamp Work?
We found a great explanation at How Stuff Works? Part of the explanation reads;
In the lamp you have two liquids which are:
- Very close in density
- Insoluble in one another
Oil and water are insoluble in one another (that’s where the expression “oil and water don’t mix” comes from), but oil and water have very different densities (a volume of water weighs a lot more than the same volume of oil). They won’t work, so you search to find two liquids that are very close in density and are insoluble.
Now you apply heat to the bottom of the mixture. In a liquid motion lamp, the heat usually comes from a light bulb. The heavier liquid absorbs the heat, and as it heats up, it expands. As it expands it becomes less dense. Because the liquids have very similar densities, the formerly heavier liquid is suddenly lighter than the other liquid, so it rises. As it rises, it cools, making it denser and therefore heavier, so it sinks.
This all happens in slow motion because heat absorption and dissipation are fairly slow processes, and the density changes we are discussing here are very slight.
A great explanation, but this starts to sound like the adults talking on Charlie Brown to my youngest; wah wah wah wah wah…
So, when I asked my intern to look at some science experiments recently, she discovered this one and didn’t realize at the time that it was the perfect explanation for my hands-on learner.
Our first attempt:
We took a clean, empty plastic bottle and filled it 3/4 of the way with water. We added blue food coloring, placed the cover on & shook it up. Then we added some oil demonstrating that water and oil really don’t mix. We then began to pour in salt. As the salt pours in, it absorbs and pushes some of the oil to the bottom and then bounces back to the top. It was a challenge to catch it in photo, but you can catch a glimpse below.
Our Second Attempt:
We took a clean, empty plastic bottle and filled it 3/4 of the way with water. This time we did not add any food coloring. We added the oil like above and then topped it off with heavy layer of glitter. As we added the salt, it collected the glitter, pulled it to the bottom and created balls of glitter that bounced back.
We can’t wait to update this post & let you know if our idea works or not. We will be adding a broken glow stick to the mix and will let you know if it’s successful or not. Why haven’t we done it yet? We have visited three different stores and have not been able to find the larger size. We’re on the hunt & will add up our discovery as soon as we can locate the right size glow stick.