The Menthos Myth?

by April
(Lilburn, GA)

Menthos Myth: Launching a Soda Rocket and Defying Odds - All you need is a candy and some raw physics to make a ten-foot geyser out of a soda bottle. See how the same invisible forces that launch soda also create massive thunderstorms in our sky if you're tired of playing it safe.

April tells us this: In seventh grade I created a Science Fair project that wasn't very original, but it did get a lot of laughs. I came close to getting in trouble but I played ignorant.

Did you know that the fizz created by a Menthos candy pebble, when placed inside a 2 liter soda bottle, actually causes some kind of chemical reaction? Well, it does!

I got together with two of my girlfriends and decided to do a very detailed experiment. The quality of of our graphs and research is what saved us from failing. The actual experiment conducted on school property was frowned upon.

If I had it to do over, I would have video-taped the various experiments and played them on a portable DVD player rather than let the explosion happen in the cafeteria. There wasn't an actual explosion, but a mess was made, nevertheless. The fact that putting the candy in the bottle caused a reaction and caused the fizz to burst through the top was very interesting to all the other kids in the class.

The science behind it impressed the teachers. What we did was got several types of soda and several types of candy. We monitored the insertion, the quantity of fizz that was created and the reaction if any.

I always had fun with science and by making learning fun, kids stay interested. You can apply science to everything in life. There is always an experiment to conduct if you put your mind to it.

Barry's Response - I've never done it myself, April, but it might be interesting.

Here, somebody had fun with it:



Search this site for more information now.

Soda Geysers and the Menthos Myth

Most people call this a chemical reaction. They're wrong. Let's look at nucleation.

1. Eruption physics Carbon dioxide is dissolved in soda (CO2). Water molecules surround this gas like a tight net. You're not starting a chemical fire when you drop a Mentos into the bottle; you're providing a type of landing strip for the gas.
   • There are thousands of tiny pits called nucleation sites on Mentos candy.
   • Surge: These pits let the CO2 form bubbles and surge upward with incredible speed.
   • Result: The liquid erupts because the gas needs space now.
2. Atmospherics (Meteorology & Air Quality) What does this have to do with our science project presentation? That's why our planet behaves like that soda bottle.
   • As the cap keeps the fizz inside, atmospheric pressure controls how gases move.
   • The Air Quality Reality: CO2 is often portrayed as the ultimate villain when it comes to climate change. Consider this: CO2 is life's fizz. Forests and oceans depend on it.
   • Some skeptics argue that Earth, like a pressurized bottle, has natural valves like volcanic outgassing that manage these cycles. Is the planet actually exploding, or is it just breathing through a complex, well-designed system that we don't fully understand?

The Strategy for Winning Your Science Fair

Use this table to plan your experiment if you want to impress the judges:

Variable	The Action	The Resulting Force
Diet Soda	Removes the sticky sugar	The geyser soars higher.
Warm Soda	Increases molecular motion	The gas escapes faster.
Crushed Candy	Multiplies nucleation sites	The reaction accelerates instantly.

Inventor's Tangent

When I heard someone tried this with sparkling mineral water to see if the natural bubbles reacted differently, they didn't. It reminded me of the aquatic environment skeptics who worry about ocean acidification. Nature buffers itself when we think of the ocean as a giant bottle of soda. It's not about living in fear of a "pop"; it's about respecting the pressure and keeping the cap clean (i.e., our environment).

Global Geyser: Expanding the Narrative

Don't just talk about candy if you want to revolutionize this project. Let's talk about aerosols. We study how tiny particles in the air cause clouds to form. They're just like Mentos! For water vapor to turn into rain, they provide nucleation sites.

A world in a grain of sand / And a heaven in a wildflower — William Blake

Imagine what dust from a desert or salt from the sea does to our weather if a candy can launches soda ten feet in the air. It's not just a mess; you're modelling the physics of thunderstorms.

Get in on the Rebellion

Do you think settled science ignores the fun and chaos of nature? Could CO2 be the Earth's version of extra fizz?

Let me know what you think! What would you launch into the atmosphere to change the weather? Please, don't say more soda - the janitors are already mad.