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The US Swim Team's Secret Weapon, Science

Hugh Pickens writes "When American Swimmer Margaret Hoelzer goes for the gold tonight in the 200-meter backstroke, part of her success will be due to a new system developed by Tim Wei, a mechanical and aerospace engineer at Rensselaer Polytechnic Institute, that uses fluid dynamics to study human movement allowing scientists and coaches to study how fast and hard a swimmer pushes the water as he moves through it. 'Wei uses a tracking technique called digital particle image velocimetry, commonly used to measure the flow of small particles around an airplane or small fish or crustaceans in water.' Wei filtered compressed air in a scuba tank through a porous hose to create bubbles about a tenth of a millimeter in diameter. When an athlete swims through a sheet of bubbles that rises from the pool floor, a camera captures their flow around the swimmer's body and the images show the direction and speed of the bubbles, which Wei then translates into the swimmer's thrust using software that he wrote."

18 of 180 comments (clear)

  1. Sexism by Ethanol-fueled · · Score: 5, Funny
    From TFS:

    "When American Swimmer Margaret Hoelzer goes for the gold tonight in the 200-meter backstroke..."
    "...to study how fast and hard a swimmer pushes the water as he moves through it."

    I'm Margaret Hoelzer, you insensitive sexist swimsuit-designing clods!

    1. Re:Sexism by DeadDecoy · · Score: 5, Funny

      Can you really fault them, most slashdotters have never seen a woman before.

    2. Re:Sexism by rehtonAesoohC · · Score: 5, Insightful

      What you've referred to is called a misplaced modifier, and it occurs when the wrong noun or pronoun is referred to as the precursor to a verb.

      For instance, note the following sentence: "I walked down the street, saw a boy and a bike, and he was walking quickly." In this example, the sentence attempts to reference the boy, but actually references the bike. The original statement is grammatically correct.

      I'm an English teacher you insensitive clod!

    3. Re:Sexism by Anonymous Coward · · Score: 5, Funny

      I'll ambiguously define your antecedent!

  2. Changing is easier said then done. by BitterOldGUy · · Score: 5, Interesting
    Swim coach Sean Hutchison, who put two athletes on the Olympic swim team, says that he used Wei's insights as the basis for every technical change he made with swimmers leading up to the Olympic trials and games this year.

    After doing something for years and years, changing the way you do something, whether it's a swimming stroke or tennis or golf swing, isn't done instantly. It takes quite a bit of concerted effort and attention to change it. I'd be really interested in how and what the coach does to get the swimmers to change.

    I've witnessed swimmers in college that have bad habits that they gained as youth and they can't seam to shake them.

    1. Re:Changing is easier said then done. by Crispy+Critters · · Score: 5, Interesting
      That depends. I remember reading about Natalie Coughlin four years ago, and one of the coaches was describing how Natalie could take a suggestion and instantly integrate it into her swim style, even in a competition. I believe that ability was seen as unique.

      It is plausible that adaptability is one trait that helped the Olympic swimmers become Olympic swimmers in the first place. Certainly it would be interesting to hear more about it.

    2. Re:Changing is easier said then done. by ckthorp · · Score: 5, Insightful

      Have you watched the Olympic athletes who have competed in Dancing with the Stars? When it comes to taking direction and altering their physical performance in a short period of time, they're absolutely awe-inspiring. If you're an Olympic athlete, you better be able to quickly make major changes based on either computerized or human coaching instructions. It's like watching a professional actor rapidly portray a half dozen different personae.

  3. It's not just technique by Solandri · · Score: 5, Informative

    It's not just better technique and the new suit. The pool is also designed to reduce waves to help lower times. A lot of the wave dissipation features described in the article have been used in tow tanks (where we tow model ships to measure their drag) for decades.

  4. Re:Interpretation? by BitterOldGUy · · Score: 5, Informative
    Hydrodynamics comes into also. So it's not just power but also how well they move through the water. Efficiency.

    I have much more power than any of the girls, well most of them, on the US Team, but in the water, they'll blow my doors off because of better technique - the ability to apply their power in the water. That's the best I can do. It's been a while since I read my swim coaching stuff.

  5. Hmm... I have a correction to the title by rehtonAesoohC · · Score: 5, Funny

    The US Swim Team's Secret Weapon: Michael Phelps.

    Though that's not very secret. Sort of like Victoria's.

    1. Re:Hmm... I have a correction to the title by Xoltri · · Score: 5, Funny

      OK we get it, he's good at swimming. Does there really need to be so many swimming events? Why don't they have 10 different softball events? You could have ones where everyone gets one arm tied behind their backs. Or one where they all have to run backwards. Another where they hop around the field with potato sacs on their legs. Or have a runner at each base and they have to do it relay style. It doesn't make any sense!

      It's event pollution. See: http://www.realmansolympics.com/

      --
      -Xoltri
  6. Swimmer gender issues by spineboy · · Score: 5, Funny

    I dunno - if you've seen some of the female swimmers, then it's not hard to make that mistake.

    --
    ..........FULL STOP.
  7. Re:The secret science is wrong by icegreentea · · Score: 5, Interesting

    And his body. He's like a dolphin. His proportions are perfect for swimming. And then he's double jointed in his ankles, elbows, shoulders AND chest. His armspan is 10cm greater than his height. All he needs now are gills.

  8. Re:Related research on the dolphin kick Phelps use by hkgroove · · Score: 5, Interesting

    That's why you can only dolphin kick for 15 meters now.

    In 25 yard pools during backstroke it was easier to dolphin kick and swim 8 yards with the last 2 dedicated to the turn.

    As for swimming underwater: Most sprinters in the 50m freestyle don't take a breath during the race. In short course (25m pool) 50m races I maybe took one breath on the way back - depends how much air I released during my turn. If I swam at the right speed I could get about 75m before needing to come up and take another breath. But this was far from racing speed.

  9. Re:Problems with slashdot...is it just me? by Anonymous Coward · · Score: 5, Funny

    No, it's not just you.

    The original slashdot page layout and comment threading system was junk. It was obviously "designed" at 3:00 in the morning after a mushroom and hash party in Taco's dorm room. They would fix it, but nobody at slashdot understands how it works.

    The recent v2.0 slashdot page layout and comment threading system is also junk. It was obviously "designed" at 3:00 in the afternoon after a martini and coke lunch at an expensive steak house. They would fix it, but nobody at slashdot understands that it sucks.

  10. There's nothing that special about the pool by snowwrestler · · Score: 5, Insightful

    It is engineered to reduce turbulence but no more than other top-level pools around the world. Pools with 10 lanes, slop gutters to eat waves, and greater then 2m depth are not unheard of. Besides, while plenty of world records are being beaten at these Olympics, plenty were also beaten before the Olympics...in the last year or two many world records have gone down at other events. Before each race NBC puts up a listing of the current world record for that event. Take a look--many are dated 2006 or 2007; some date back a few more years, but none are very old.

    We happen to be in a period of dramatic change in swimming right now, and there are probably a number of reasons. If you want to point to just one, it is probably that there is a lot more money in the sport now. So Michael Phelps could afford, through endorsements and grants, to train at a full-time professional level since he was an early teen. This has huge implications for his technique, fitness, health, and mental toughness for competition.

    --
    Build a man a fire, he's warm for one night. Set him on fire, and he's warm for the rest of his life.
  11. Faster lap times due to ... by PPH · · Score: 5, Funny

    ...being chased. By sharks. With lasers.

    The high diving competitions are the result of releasing the shark and playing the video of the swimmer leaping out of the pool backwards.

    --
    Have gnu, will travel.
  12. Re:The secret science is wrong by ToastBusters · · Score: 5, Funny

    And his body. He's like a dolphin. His proportions are perfect for swimming. And then he's double jointed in his ankles, elbows, shoulders AND chest. His armspan is 10cm greater than his height. All he needs now are gills.

    Dolphins have gills?