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Solving the Great Shower Curtain Mystery

parvati writes: "The New York Times is reporting that a UMass professor, Dr. David Schmidt, used computer modeling to figure out why shower curtains suck inward during showers. He designed an image of his mother-in-law's shower, filled it with 50,000 3D velocity/pressure sensors, and turned on the virtual water. 1.5 trillion calculations later, he found that drag on the falling water drops creates a mini-hurricance, producing a low-pressure 'eye' that attracts the shower curtain."

9 of 244 comments (clear)

  1. Moral of the story by Sabalon · · Score: 5

    Plain and simple - Hampton Inn, who has the thinnest curtains I've ever seen, that suck inwards at the utterance of the words "I'm going to take a shower", needs to install some magnets on the bottom, or just spend an extra dollar per room for a real curtain.

    Better yet, the plexiglass doors...that'd be one shower to make them bow in!

  2. Re:Registration-free link by FFFish · · Score: 5

    Slashdot should just get its own "partners" link already. Why the hell do we need to go through this dumb-ass two-step system where the main article posts some NYTimes registration-required link and someone else ferrets out a no-reg-required link?

    Cut to the chase already, Slashdot. Beg, borrow or buy a damned registered partner account with the NYTimes and be done with it!


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  3. My own data by spineboy · · Score: 5

    My own research suggests that the likelyhood of the shower curtain being attracted to your skin is directly proportional to the amout of scum on it.

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  4. What are we going to do tonight, Brain? by Greyfox · · Score: 5

    Tonight, my dear Pinky, we shall create a superweapon that creates hurricanes! First, we shall need to build the WORLD'S BIGGEST SHOWER STALL! ...

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    I'm trying to teach myself to set people on fire with my mind... Is it hot in here?

  5. Finally! A believable answer by renard · · Score: 5
    Cecil Adams addressed this question many years ago in an unforgettable column of The Straight Dope. But this latest approach is even better.

    First a quick summary (apologies to those who read the article). Historically the billowing shower-curtain theorists have been divided into two camps:

    1. Those who appealed to the chimney effect - hot air rising within the shower causes cool air to come in from below. This hypothesis can be readily defeated by taking a cold shower and observing that the curtain billows nonetheless.
    2. Those who appealed to the Bernoulli principle - decreased pressure exerted by air in motion - the same physics that allows airplanes to fly and causes two sheets of paper to stick together when you blow between them (try it!). This hypothesis also seemed a bit shaky since (a) the air in a shower never seems to move that fast; and (b) there's a potential confusion of cause and effect going on here (for the shower curtain to billow, clearly something must be happening with the air pressure...).
    Now comes David Schmidt to demonstrate that both of these camps are wrong (in this he and Cecil agree). His theory instead focuses on the deceleration of the water droplets by the air producing a cyclone effect within the shower. This theory is similar to, but distinct from, the ``entrainment'' theory that Cecil put forward so many years ago. And to me, significantly more believable.

    The same dynamics that causes hurricanes, right there in our very bathrooms! Score one for Schmidt and his finite element approach to a classic problem.

    -Renard

  6. Why would he want to do that? by 11thangel · · Score: 5

    Since I'm not married, I'm not certain, but would many of the readers here want even a mental image of their mother-in-law's shower, much less a super accurate computer picture?

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    I am !amused.
  7. Quality of Slashdot Readers by Elentar · · Score: 5
    Judging from the large number of posts here from people who didn't bother to read the article, one can draw one of several conclusions: (a) Many Slashdot readers think they know everything already, (b) Many Slashdot readers do not take showers, or (c) Many Slashdot readers are secretly employed by physics textbook manufacturers.

    -Elentar

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    The wheel it turns, around and around, with an ancient rumbling sound.
  8. Re:Great! by RhetoricalQuestion · · Score: 5

    Now I can die happy knowing that shower curtains get sucked inward due to a small hurricane. I love science! We could be spending research time finding a way to get 500 miles to a gallon instead of worrying about showers.

    Think of it as an indirect approach. For example, I was reading somewhere (cannot recall the source, but it was some magazine) about a scientist who decided to figure out why it was that coffee spills always dried with a dark ring around the outside. A whole lot of research later, science now knows a lot more about how molecules interact in fluids, which has led to practical applications such as (among many others that I cannot remember) fast-drying paint.

    Many people make the same argument you're making about fields like pure mathematics -- the research doesn't always have any immediate practical value. But the knowledge often makes itself valuable in everyday life in unanticipated ways. How do you really know if a particular scientific "discovery" is useful unless you know what that discovery is in advance?

    It's a disturbing trend nowadays that believes research time should only be spent on immediately practical applications. The pursuit of pure knowledge, or even simple curiousity, is increasingly pushed to the side. Yes, research is time-consuming and often expensive, but to solely measure the value of attaining knowledge based on its immediately foreseeable applications is (IMO) somewhat short-sighted.

    Now I admit, I have no idea how knowing that a shower creates a small huricane will become personally useful to me. But that does not mean that some aspect of this will not become useful in the future.

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    I can spell. I just can't type.

  9. Million dollar funding superchallenge! by Nathdot · · Score: 5

    Some of my own proposed projects:

    * Why the last dribbles of softdrink never make it out of the can
    * Why drivers lisense photos always turn out bad
    * Why I always sound like a dork on answering machines


    I plan to model each one of these confounding human mysteries on a supercomputer using not 1, not 2, but 3 trillion!!! calculations...

    Now!... Gimme that sweet sweet grant money!

    :)