Inside: Is there anyone who doesn’t like this classic science activity? DIY Lava Lamp is easy to make and fun to study. Detailed instructions, a demonstration video, a simple scientific explanation, and science printables are included below.
At age six, I was tremendously lucky to get a decorative night light like no other I’d ever seen. It had a black frame that blended and disappeared into the darkness at night. Inside the tall vertical canister, there was a faint yellowish glow. In gorgeous slow motion, strange, pale, extraordinary shapes glopped around, bumped into each other, morphed together, broke up, and floated up and down, up and down … It was, of course, a lava lamp.
I still remember the wonderful sense of calm and peace that descended on me as I watched the waxy shapes float until my eyes grew heavy, and I drifted off to the land of nod.
You can be sure that the first thing I wanted to buy when I got pregnant with my first child was the lava lamp that I had as a child.
Alas, it was not possible.
For reasons I don’t understand, modern lava lamps are much different. For one thing, they are colorful, extremely bright, and over-stimulating rather than soothing. Plus, they are much shorter, so the travel time of each blob is limited and utterly ineffectual in inducing sleepy vibes. Silly people.
I did end up buying the calmest (in my opinion) lava lamp I could find, but it wasn’t successful.
The History of Lava Lamps
Lava lamps were invented by Edward Craven, a British accountant who had a secret passion for making things. Craven wanted to use a lightbulb for the heat source to make a lamp more beautiful and used a plastic bottle for his first prototypes.
Apparently, this account was also a scientist, experimenting with different liquids until he found a water-based solution viscous enough to slow down the movement of the wax-based blobs floating through it – the exact formula is still a secret.
Recipe perfected, Craven created a company called Astro Lamps to sell his invention, which he then sold to a US company called Lava Lights in 1965. It was perfect timing and fit right in with the aesthetic look of the 60s – ooey-gooey-groovy! These lamps were not about light, exactly. They were about the atmosphere and getting lost in the beauty of the momentary blob.
Lava lamps fell out of popularity for a while but came back hard in the 90s to grace the bedrooms of a new generation of kids.
I think the appeal of the lava lamp is perennial, and I’m so excited to pass them on to my kids.
Why You Should Make This Lava Lamp
- It’s a mental bridge. One of the reasons many parents panic when they hear “play with me, mommy” is that our brains are not tuned to the “play” wavelength. We just don’t know what to do. Kitchen science activities are an excellent bridge between the serious adult world and the goofy kid world when you want to have some fun with your children.
- It encourages curiosity. Projects like this can be the first step towards a lifelong love of science. We shouldn’t be too surprised by this. Most of the things that happen in the kitchen involve chemical processes explained by science – raising bread dough, raw eggs becoming solid omelets, and mixing ingredients to make lasagna! Scroll down to the science behind the experiment once you make your lava lamp, and download the printables.
- It’s a babysitter. Lava lamps might keep your kids entertained for a while after you’re done making it. It’s a good way to sneak in some me time if you have a project or two waiting for your attention.
- It’s hands-on learning. In the world of digital learning, this hands-on activity helps kids explore the world around them through both mind and body.
- It’s sneaky spring cleaning. Not only does it allow you to use up those expired Alka-Seltzer pills, but maybe while looking for it, you will find a few other things in your medicine cabinet that need to go. Lava lamp-induced spring cleaning 🙂
- It’s meaningful. You will never regret the time spent with your kids doing science experiments!
Reminder: If you want to turn this fun kids’ activity into a science lesson, scroll down to the science section below and download our science printables, which go perfectly with this activity.
How to Make a Lava Lamp
What you need
Mason jar, plastic bottle, or tall glass or flower vase (note: if you are using a plastic bottle, pick a brand with an easily removable label)
(Optional) glow-in-the-dark pigments
What to do
1. Fill 1/4 of your container with water.
2. Add oil.
How much? About 1/2 cup.
3. And some food coloring
The red-colored droplets are heavier than oil and go down in our glass. Since food coloring doesn’t dissolve in oil, it passes the oil layer without dissolving. But once it’s in the water layer, it starts dissolving. I just love the way it looks when it just starts the process. Isn’t it just gorgeous?
4. Break Alka-Seltzer into quarters.
You can try bigger and smaller pieces as an experiment, but for us, 1/4 of a tablet worked the best.
5. Drop a quarter of an Alka-Seltzer tablet into the jar.
Now watch the magic!
Do you want to take it a step further? Add some glow-in-the-dark pigments.
The Science of Lava Lamps
Have you ever wondered how DIY lava lamps work?
Although they look cool and fun to make, they are actually based on a scientific principle.
The oil in the lamp floats on top of the water because it is less dense than water. As we mentioned above, food coloring and water have the same density so it will sink down into the water.
Once you add the Alka-Seltzer tablet, it sinks to the bottom and dissolves, releasing carbon dioxide gas.
As the gas is lighter than water, it rises to the top, bringing with it some of the colored water.
But once it reaches the top, the air escapes from the colored blob, and the water gets heavy again and sinks. This process will continue until the tablet is completely dissolved, creating a mesmerizing lava lamp for you and your kids to enjoy!
When you notice the reaction to being to slow down, just add more tablets of Alka-Seltzer to keep the magic going.
Do you know how the traditional Lava Lamps work? Read below!
How do Lava Lamps work?
Inside a lava lamp, you see two liquids, but they’re very different from each other, and they don’t mix!
Well, they’re just not that attracted to each other. Lol, let me explain…
The water-based solution that the blobs float in is a “polar” liquid. This means that the water molecules have both a positive charge in one spot and a negative charge in another spot – they’re “polarized.”
So they are always looking to balance themselves out and attract other positively or negatively charged atoms to do so – it’s the same process that attracts oppositely charged magnets together. This is why water mixes with so many other substances and is known as the “universal solvent” – it can dissolve practically anything because it wants to correct its lopsided charges!
But not oil.
Water cannot dissolve, incorporate, or otherwise mix with oil. That’s because oil is non-polar. Its atoms’ electrical charges are already perfectly balanced between positive and negative, so it doesn’t need to attract other atoms to balance out the charge. It’s neutral and just keeps to itself.
In a traditional lava lamp, the oily blobs are mixed with a few other things to make them denser (oil normally floats above water since it has a lower density). When you turn on the lamp, the heat causes the oily blobs to expand and become less dense. Once they’re less dense than the watery solution they’re in, they start to float to the top! But once they’re away from the warm lightbulb for a few seconds, they cool down, become denser, and sink down again, where they warm up again…and again…and again.