Science and techno world topic: Future
To understand how fast a human can ultimately run, we
need to go beyond the record books and understand how Usain Bolt's legs work.
To understand how fast a human can ultimately run, we
need to go beyond the record books and understand how Usain Bolt's legs work.
In 2008, at the Beijing Olympic Games, Jamaican sprinter
Usain Bolt ran the 100m in just 9.69 seconds, setting a new world record. A
year later, Bolt surpassed his own feat with an astonishing 9.58-second run at
the 2009 Berlin World Championships. With the 2012 Olympic Games set to begin
in London, the sporting world hopes Bolt will overcome his recent hamstring
problems and lead yet another victorious attack on the sprinting record. He is
arguably the fastest man in history, but just how fast could be possibly go?
That’s a surprisingly difficult question to answer, and
ploughing through the record books is of little help. “People have played with
the statistical data so much and made so many predictions. I don’t think people
who work on mechanics take them very seriously,” says John Hutchinson, who
studies how animals move at the Royal Veterinary College in London, UK.
The problem is that the progression of sprinting records
is characterised by tortoise-like lulls and hare-like… well… sprints. People
are getting faster, but in an unpredictable way. From 1991 to 2007, eight
athletes chipped 0.16 seconds off the record. Bolt did the same in just over
one year. Before 2008, mathematician Reza Noubary calculated that “the ultimate
time for [the] 100 meter dash is 9.44 seconds.” Following Bolt’s Beijing
performance, he told Wired that the prediction “would probably go down a little
bit”.
John Barrow from the University of Cambridge – another
mathematician – has identified three ways in which Bolt could improve his
speed: being quicker off the mark; running with a stronger tailwind; and
running at higher altitudes where thinner air would exert less drag upon him.
These tricks may work, but they’re also somewhat unsatisfying. We really want
to know whether flexing muscles and bending joints could send a sprinter over
the finish line in 9 seconds, without relying on environmental providence.
To answer that, we have to look at the physics of a
sprinting leg. And that means running headfirst into a wall of ignorance. “It’s
tougher to get a handle on sprinting mechanics than on feats of strength or
endurance,” says Peter Weyand from Southern Methodist University, who has been
studying the science of running for decades. By comparison, Weyand says that we
can tweak a cyclist’s weight, position and aerodynamic shape, and predict how
that will affect their performance in the Tour de France. “We know down to 1%,
or maybe even smaller, what sort of performance bumps you’ll get,” he says. “In
sprinting, it’s a black hole. You don’t have those sorts of predictive
relationships.”
Our ignorance is understandable. By their nature, sprints
are very short, so scientists can only make measurements in a limited window of
time. On top of that, the factors that govern running speed are anything but
intuitive.
