Who could turn down an opportunity to make a mess with shaving cream and learn about color mixing with the always fun Lisa Murphy? Not me! When I learned that Lisa and her husband, Tom, were planning a trip to Colorado, I asked if she would be a guest on Science Mondays at 9News. The real fun for me, however, was getting to spend down time with Lisa away from the hustle and bustle of a conference. I’m honored to get to consider her a colleague and friend. We laughed about the idea of getting to spend an entire weekend together with a few hundred of our favorite early childhood teachers for something that would probably be well beyond extreme. I don’t think we’d ever be invited back to that hotel. Just a thought…
Watch Lisa in action as she shares one of her signature color mixing demos with shaving cream!
It’s a demonstration that almost has to be seen in person to believe. Otherwise, you’re likely to say, “It’s fake… there’s no way that could happen!” As you’re watching the video below, please remember that there is absolutely no trick photography. When disbelievers see the demonstration performed live, the reaction is nothing short of astonishing. Based on our past experience, we know that color mixing is not a reversible process. Mix red and blue and you make purple. Separating the colors back into their original form is not only tricky but incomprehensible for many of us. Watch the video… you’ll see why we call it a “Twist in Time.”
I believe what’s happening here is very low Reynold’s number laminar flow, which means that there are many parallel layers of “sticky” (or viscous) fluid. As the handle is turned, the dyes remain within their original layers and do not mix with each other, even as they are spread out over their individual layers. As the crank is turned backwards, the process is inverted, and since there is no fluid turbulence in laminar flow, the process can be inverted almost perfectly. You’ll find more discussion
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