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 about this on our Twist in Time – Laminar Flow page in the science experiment library.

11 replies
  1. Ashley
    Ashley says:

    I would love to do this! Can you tell us where you got the pieces for the container or sell them on your website! Very cool!

    Reply
  2. Ashlee
    Ashlee says:

    That was so cool. I need a science project to do for the science fair and i was wondering where do you buy the contanier thing that he was using. Well if anyone knows can you post it please i really need it!! THANKS SO MUCH!! BUH BYE!! 🙂

    Reply
  3. David in Michigan
    David in Michigan says:

    I enjoyed the demo. Would you provide some dimensions on the two cylinders? I guess it works better if the gap is small relative to the cylinder diameter, true?

    When the color is injected, is each dot at the same distance from the axis of the cylinders?

    Nice demonstration.

    Reply
  4. Steve Spangler
    Steve Spangler says:

    Thanks for the nice words. I agree… it’s a beautiful demo. There’s no science to the size of the tubes. Just make sure the gap between the two cylinders is about an inch or so. Again, it’s really a matter of trial and error. Just squeeze in the dye to make the dots and give it a try.

    Let me know if it works for you. Love to see pictures or your video.

    Reply
  5. Meryl
    Meryl says:

    Sir….. I would like to know whether it is possible to make the container …. if yes… what are the materials required?…. I was planning to do this experiment for the school science fair…

    Reply

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