It seems to be well-known fact around work that if one wishes to discuss how to harvest wasted energy from toilets, fabricate alien alloys, profit monetarily from planetary rotation, use crop rotation and a little Korean culinary acumen to remove soylent green’s unhealthful by-products, turn the sky into a plasmatic nightlight, convert an electric lawnmower into a hovercraft, use a surplus supercomputer circa 1983 to rearrange the entire earth into a slush of magma and powdered bits in a 50-hour time span, or bounce any other Teslian schemes, I’m always happy to listen and (at my best) provide insight.
So, while the above mostly stem from anecdotal conversations with our most creative engineer, it is hardly surprising that a coworker would seek my advice on building a volcano.
No, not a full-scale functioning volcano (though I have a few ideas on how to accomplish it), but a miniature, anodyne volcano. You know, papier-mâché, modeling clay, the works. A colleague’s seven-year-old daughter needs to build one for a school project over the next month, and my friend wanted a few ideas to pass on.
Who doesn’t remember this project? If memory serves as guide to the future, every kid in the class will show up with a bottle of baking soda and a pitcher of vinegar. Honestly, I suspect the perception of volcanoes as conical mountains pouring out landslides of red rock stems more from the model than the model does from the perception. In reality, there are many varieties of volcano, few of which bear any recognizable qualities with the standard classroom miniature.
By far the most numerous example is the submarine volcano, in which the pressures of the underground world force a thinned spot in the crust upward into a dome-like mound, and where magmatic gases and small quantities of lava escape to be cooled by the water around them. So, my idea is that the kid makes a hollow, open-bottomed mound out of plastic/oil-based modeling clay, carves cracks through it with a knife (or even a toothpick), weighs it down in an aquarium or goldfish bowl, and fills it with water. Inside, under the mound would be placed a red aquarium light that would be visible through the fissures, giving the impression of great heat. Keeping the light company would be an aquarium pump, so that bubbles of air, signifying steam, would rise through the cracks. The only difference between bubbles of air and bubbles of steam is that air rises more slowly, but that is accurate to the scale of the model!
For one reason or another, this idea was nixed and the question became how to create smoke to go along with the baking soda reaction, without using dry-ice. I brainstormed a compact and easy to make fog machine, not to mention a few hazardous exothermic reactions. Yeah, dry-ice is probably the best bet. That said, my thinking did produce one other interesting idea. Instead of a lava flow that stinks of bad wine, why not achieve the same effect with Alka-Seltzer® and a bit of surfactant to keep the bubbles from popping? What followed was this slideshow, created upon my arrival home.
That’s four Alka-Seltzer® disks (halved to get through the opening) at the bottom of a 330ml bottle. My bathtub serves as a splash-shield.
The beaker contains dish-washing detergent and food-coloring in water.
...and thar she blows!
This is about the four minute mark, but there’s still a good head on the eruption.
Just over fourteen minutes after ignition and the bubbles are still coming out in a steady stream. I’ve already begun rinsing the tub which, by the way, quickly became entirely red-free. About a minute after this picture was taken the reaction slowed to the point that it could not replenish the bubbles as quickly as they burst. Still, I challenge the standard reaction to match this one’s longevity.