Fastest? Longest?

It wasn't so long ago that the idea of running a mile in under four minutes was unthinkable, and many scientists even set out to prove that it was humanly impossible. But in 1954, Roger Bannister famously broke that barrier, and in the half-century since, that record has incrementally been lowered by nearly 17 seconds.

Who holds the current record? You'd think it would be a household name, but it required a Google search to reveal that it's one Hicham El Guerrouj of Berkane, Morocco, who broke the world record in Rome on July 7, 1999. His time? 3:43.13, just a smidgen less than Noah Ngeny's of Kenya: 3:43.40. (For the record, the women's world record belongs to Svetlana Masterkova of Russia, who ran one mile in 4:12.56 in Zürich, Switzerland, on August 14, 1996.) Now you know!

So the question remains -- what is the fastest that a human can run a mile? Sure, we know what it is today, but will the record continue to be broken? By the year 2050, will someone clock a 3:30 mile? Is a 3-minute mile ever in the cards? (That would be 20 MPH). Logic dictates that --no matter how fantastically humans evolve, no matter how strong legs and lungs become -- there must be some natural limit to human speed. But what is it? And how will we know when it's reached? Won't there always be someone who can trim a tenth or even a hundredth of a second off it?

One of the Websites that carried the information about Hicham El Guerrouj was http://thelongestlistofthelongeststuffatthelongestdomainnameatlonglast.com/ . Which naturally makes one wonder which domain in fact does hold the record for being the longest. Domain names are not supposed to exceed 63 characters, so theoretically this would qualify. (Since one could go blind actually trying to count all those characters, it's best to just presume there must be 63 characters there -- otherwise why bother with such heft?). But then along comes http://www.thelongestdomainnameintheworldandthensomeandthensomemoreandmore.com/ (also 63 characters, one presumes, though admittedly it looks longer), and tries to get the Guinness World Records folks to ordain it as the official longest. Guinness politely declines:

"After having ... given full consideration..., I am afraid we are unable to accept your proposal as a record... because there is no merit whatsoever in this. It takes little to no effort and is similar to taking the largest number in the world and then adding 1 to it."

Which brings to mind a recent news item about breaking records -- but in this instance, "adding 1 to it" can mean the difference between life and death. It seems David Blaine, Mr. Endurance himself, can hold his breath underwater for more than 16 minutes -- 16:09 to be precise. That's just 5 seconds short of the Guinness world record, which he plans to break on April 30 on (where else?) the 'Oprah' show.

Now the New York Times report on all this included some interesting facts. In the early 20th century, Houdini was celebrated for being able to hold his breath for 3-and-a-half minutes; with minimal training, the reluctant Times reporter was able to last 3:41 . (Synchronistically -- but irrelevantly -- almost as long it takes the world's fastest man to run a mile.)

And it's not just the lengths to which divers go that has dramatically improved in recent decades, but also the depths:

"Researchers in the 1960s calculated, based on lung capacity and the effect of water pressure, that humans couldn’t dive deeper than 165 feet. Today free divers are going down more than 600 feet and returning in apparently fine shape."

So as with the four-minute mile, the question remains: what are mankind's natural limits? If David Blaine indeed breaks the record (on live TV!), how long will it be before someone else comes along and breaks it again?

Surely there must be an absolute limit on how fast a man can run a mile, on how deep he can free-dive, on how long he can hold his breath. But what is it? And how will we know when it's been reached?