I love these little aggregator coincidences: this afternoon The Science of Sport puts up a good piece on swimming’s credibility crisis, and this evening I catch this NewScientist article on a new nanotech fabric that is unwettable (too bad the word “waterproof” is already in play). You can leave it in water for hours and it comes out bone dry.

• First, I have to express my awe at the 100 meter dash. If you didn't see it live, you must watch Usain Bolt's world record run. Sweet Mother of God. His semifinal heat looked like that too; so relaxed, coasting to victory. Imagine how much he would have beaten the record by if he hadn't started celebrating 15 meters (!) out. Also, definitely watch the super-slow-mo version. I love watching the timer count off the tenths in the background as he runs by, celebrating. Related, here's Tyson Gay's hamstring injury footage. It's like a NASCAR crash. I knew those guys generated tremendous power, but I didn't truly appreciate how much until watching it go very wrong. Looks nothing like one of my hamstring pulls. You'll be prompted to install Microsoft's Silverlight plugin to watch these. It's basically Microsoft Flash (like we needed another rich media format).
• Admit it, Phelps has you thinking about getting into the pool. Tim Ferriss has a good post up on the Total Immersion program: How I Learned to Swim Effortlessly in 10 Days and You Can Too. My big obstacle is the inability to keep the water from going up my nose.
• Discover magazine: 20 Things You Didn't Know About Sports Technology.
• Science stuff. Modern Forager on what happens when you fast: Part 1, Part 2, and Part 3.
• More science stuff. Lyle McDonald on leptin: Part 1 and Part 2. Much more complicated than some of the recent popular press stories imply.

I just noticed this really cool workout that I WON'T be doing anytime soon from the T-Nation Third World Workouts article:

Underwater rock runs

Our boats would be anchored about 100 yards off the beach, in around 18 feet of water. We generally used these as the markers, but the workout can be performed just as easily if you run parallel to a beach. You can also use the deep end of a pool. (Just check with the lifeguards first so you don't cause an incident.)

Each two-man team picks a large rock and races to the boat with it. The first man carries the rock while the second man swims above him on the surface. Then they switch. Once they reach the boat, a mooring line is dropped in the water and the rock must be carried up the line onto the deck of the boat. From here, knock out 50 pushups, throw the rock back into the water (check for swimmers first), and return it to the beach.

18 feet deep!? I think by the time I got down there I'd have to come right back up. I also get water up my nose no matter what I do, so I can't imagine this is the workout for me, but man it sounds like fun if you can swim. How the heck one climbs a mooring line while carrying a heavy rock though, I have no idea.

Y'gotta love any description of a physics puzzler that includes this:

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.

Got there via a roundabout route, from this Jason Kottke page relaying a Cecil Adams answer to a plane-on-a-conveyor-belt problem.