July 23, 2008

How the Mentos Geyser Works - Theory Confirmed!

It's probably the most asked question we get... "How exactly does that experiment with the Mentos and Diet Coke really work?" From the outset (nearly eight years ago), we hypothesized that the exploding soda was a physical reaction, and the key factor in the release of carbon dioxide was the microscopic pits on the surface

of the chewy mint. However, there was no real scientific study that anyone could point to as the definitive answer... until now. In the June issue of the American Journal of Physics, Tonya S. Coffey, an assistant professor of physics and astronomy at Appalachian State University, in Boone, N.C., and her team of fearless physics students reported on the ingredients, temperature dependence, duration, and other parameters of the suddenly famous Mentos-Diet Coke reaction.

There has been considerable debate over gum arabic (found in the coating of the mint) and the role it plays in the physical reaction. Coffey’s group was able to confirm that the surfactant gum arabic is a key component of the reaction: It reduces surface tension, thereby

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July 8, 2008

Mentos Geyser Explodes on Photography Blog

In our continuing quest to find interesting blogs and bloggers, we ran into Leah Simmers Photography Blog, where she was capturing her experience with Mentos and Diet Coke. Thanks to Leah for letting us share some her unique geyser pictures here. Check out Leah's full blog post here. And yes, that is the Geyser Tube she's using to launch that screaming geyser.

July 1, 2008

Science Chat on Irish Talk Radio

Sean Moncrieff is the host of the Afternoon Show on Newtalk 106-108 fm in Ireland. This nationally syndicated show features news stories ranging from the serious to the zany... maybe that's why they called. While waiting for my segment, I listened to the show and quickly realized how much I want to speak again in Ireland. I first lectured at the Irish Science Teachers Association in 1997 and again in 2000. I shared a few science demos and they taught me the finer points of drinking lots of Irish beer. Here's my interview with Moncrieff.

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June 24, 2008

ABC News Breaks the Mentos Story… only three years late!

This story came across my Google alerts today from the crack team at ABC News... "Science of Mentos-Diet Coke Explosions Explained." My fingers couldn't click on the link fast enough. New research finally explains this amazing phenomenon? Here's the opening sentence of the story... The startling reaction between Diet Coke and Mentos sweets, made famous in thousands of YouTube videos, finally has a scientific explanation. A study in the US has identified the prime factors that drive the fizzy plumes from Coke bottles: the roughness of the sweet and how fast it plummets to the bottle's base. What... this is the big discovery? The Mentos chewy mints have a rough surface and they're heavy? Well, they're absolutely correct and they confirmed the original Mentos Eruption explanation published back in 2005. Tonya Coffey, a physicist at Appalachian State University in Boone, North Carolina said, "This was a good project for my students to study because there was still some mystery to it." Hats off to Coffey and her students for publishing her findings and bringing peer review to the Mentos Geyser experiment.

However, it … (more...)

June 24, 2008

Mentos Geyser Records Keep Exploding

So, America throws it back to the Europeans... from Louisville, KY to Turiba University in Latvia there is a new Mentos and Diet Coke World record. On June 19th, 1,911 students from Business University Turiba in Latvia launched an amazing geyser eruption and landed themselves in the Guinness Book of World Records, just over a month after students at Male High School in Kentucky launched 1,800 simultaneous geysers to earn their own world record status. The Latvian University students were celebrating the school's 15th anniversary, and what better way to celebrate than with Mentos and Diet Coke. Check out the video of this monumental occasion. Now, who's next...