Swimming in syrup is as easy as water

"The fluid looked like snot. I don't know how to describe it any more poetically."

It's a question that has taxed generations of the finest minds in physics: do humans swim slower in syrup than in water? And since you ask, the answer's no. Scientists have filled a swimming pool with a syrupy mixture and proved it. [...]

The most troublesome part of the experiment was getting permission to do it in the first place. Cussler and Gettelfinger had to obtain 22 separate kinds of approval, including persuading the local authorities that it was okay to put their syrup down the drain afterwards. [...]

While it might sound like a trivial question, the principle is actually fundamental. Isaac Newton and his contemporary Christiaan Huygens argued the toss over it back in the 17th century while Newton was writing his Principia Mathematica, which sets out many of the laws of physics. Newton thought that an object's speed through a fluid would depend on its viscosity, whereas Huygens thought it would not. In the end, Newton included both versions in his text.

Hamstrung by their lack of access to guar gum or competitive swimmers, Newton's and Huygens' work was mainly theoretical. Cussler's demonstration shows that Huygens was right, at least for human-sized projectiles.

The reason, explains Cussler, is that while you experience more "viscous drag" (basically friction from your movement through the fluid) as the water gets thicker, you generate more forwards force from every stroke. The two effects cancel each other out.


20 Responses:

  1. feren says:

    And, while it may be cliche... the old Fark headline rings true: Still no definitive cure for cancer.

    Please tell me these folks didn't get funding for this little "breakthrough."

    • ammonoid says:

      They had to have some kind of funding to pay for the syrup.

      • feren says:

        This must have some sort of military significance. I have to maintain that belief, or I risk going stark raving mad from knowing time, effort and money was expended on this "just because." Although I have this deep-seated fear that if there actually is a military application for this discovery someday it will appear on the History Channel's "Tactical to Practical."

        • ammonoid says:

          If that bugs you, what do you think about peep research,. Those guys must work for some kind of lab to have access to liquid nitrogen. Why *not* fill a swimming pool with syrup to test an obscure scientific principle!

          • brokengoose says:

            You can buy liquid nitrogen at the same place that your nearest august research lab does: the local welding supply store.

            • ammonoid says:

              Not having welded anything ever, I did not know that. Thank you for the education. Though I think the peep research guys do (or did, that page is many years old) work at university or something - some of the pictures look like they were taken in a lab.

          • d1663m says:

            A much more thorough inspection of a particular (peculiar?) snack food was done at the TWINKIES project.

            Though... twinkies project might just be a ripoff of the peeps research institute page.. I don't really know for sure. But *I* saw TWINKIES project first. So therefore it's the original. :)

    • jwz says:

      If we don't fund basic research like this, how will we ever encourage children to go into Mad Science?

      • feren says:

        For starters, we could buy much larger lots of sodium for high school chemistry labs. Then with the remaining funds we could launch massive media campaigns urging the students to throw the sodium into the school's swimming pool.

        I suspect that adolescents are susceptible to coercion into certain fields of study when said encouragement is accompanied by large explosions. I know I was.

        • mrangel says:

          That's not necessarily as good an idea as it sounds. Explosions may be cool and all, but the pool at my old highschool needed some serious repairs after one of the science teachers was asked to dispose of some sodium that was deemed unstable.

          Probably best just to throw it onto the field after it's rained.

  2. What they've proved experimentally is what I'd conjecture might be true... but I'm kind of surprised that the two exactly cancel each other out.

    (And, not like it matters, I've both actually swum competitively and studied some physics, so this isn't totally out of my ass.)

    Intuitively, the resistence due to viscosity would be a result of surface area and possibly mass, whereas the speed increase should be a result of physical strength and surface area of propelling surfaces (take Australian crawl: mostly the hands, a little bit the feet; all else is drag, unless everything I've ever been taught about swimming fast by way of streamlining is total bunk). Neither surface area (of the whole mass moving through water) nor mass is a direct function of strength or surface area (of the propelling surfaces).

    Also, you need continuous propulsion for this to work: shoot a bullet into guar syrup and it'll lose speed faster than if you shoot it into water (for the same reason that objects only fall at the same rate in a vacuum, and the apocryphal tale of dropping a ball and a feather at the same time from the tower in Pisa is a thought experiment, not a reality).

    I'd also question whether greater bouancy of the same surface area in guar syrup than in water didn't have something to do with it. (It's a commonly held belief of swimming coaches that a swimmer is at his fastest while airborn, not while in the water, though that may have more to do with propelling from the starting block with full leg strength than it does with the consistency of air versus water.)

    So, I guess I'm somewhat gratified that their definition of "same" is "within 4%".

    • There has to be some kind of limiting effect -- imagine that instead of syrup it was something that would slowly set. One would expect that the speed of the swimmer would not simply drop instantly to zero at the moment it finally set, but rather to tail off. Though the curve could be a strong reverse-elbow.

      • Should we then propose further research into swimming through jello, with later progression to materials such as liquid latex or spirit gum..?

        It's for Science™, after all...

  3. autodidactic says:

    Goddess bless after-hours r&d kink parties. Otherwise, where would science be?


  4. nzchrisb says:

    And how on earth can there be no video or even pictures! No no no funding wasted I say.

    • jesus_x says:

      I agree completely. If you're going to filla pool with synthetic snot and make a guy swim in it, at least take photos!

      • greatbiggary says:

        Nature.com seems to be a little behind. There's a tiny pic here, but it says the test was performed August of 2003. I found a few other links through google supporting the date.

        • nzchrisb says:

          Ah ha well done. Quoting from here.

          In mid-August, his query and theory were put to the test in an experiment he funded at the University of Minnesota that was equal parts deep science and reality TV. Study participants, including swimmers from the Gopher men's and women's swim teams, swam trials in both a regular pool and a pool filled with 700 pounds of guar--a bean-extract thickener used in ice cream and shampoo--mixed with water. Cameras from virtually all the Twin Cities media outlets ate up the spectacle but stayed out of the guar, and newspapers and TV stations from around the country picked up the story.

          So there's footage out in the real world.

  5. spendocrat says:

    Hamstrung by their lack of access to guar gum or competitive swimmers

    That's pretty funny.