A Bolt of lightning

This is unbelievable.

Jamaica's Usain Bolt, the newly crowned "world's fastest human," has made me seriously reconsider the potential of the athlete. Perhaps the only limitations are the ones we place on ourselves.

Twenty years ago, when Ben Johnson ran a stunning - but steroid-fueled - 9.79 in the 100-meter finals of the Seoul Games, I assumed there wasn't much more advancement in store for the next generation or so. To legitimately break such a mark would require someone more machine than muscle, I thought.

Or maybe not.

Because of Johnson and a laundry list of others, I don't want to be naive here - I'm sure Bolt's post-race urine test will be the subject of much interest. But until proven otherwise, the 21-year-old Bolt (way out front in the picture above from the New York Times) has just shattered - perhaps forever - my perception of the speed limit for humans. There really might not be a ceiling here.

And that puts Michael Johnson's otherworldly 200-meter world record of 19.32 into play, too. Supposedly, the 200 is Bolt's best race.

What's possible here? 19.2? 19.1? 18.9? My mind reels at the potential. Bolt has made the unbelievable seem believable again.