Is there an absolute threshold for human physical achievement? That's the question on many curious minds now that the Olympics are in full swing. Some world records, like U.S. sprinter Michael Johnson's 400m time of 43:49 seconds, set in 1996 and still an Olympic record, look like they'll never be broken. Meanwhile, records in other sports, such as swimming, are shattered all the time. Is it possible we'll reach a day when a world record will stand forever? Science says no, but soon setting a new record will be incredibly hard to do. Here, a guide to the science behind record-breaking:
Why will record-breaking become harder?
The math behind record-breaking is such that over time, the frequency with which records are broken will continually diminish. "At a certain point, we'll have rolled the dice so many times that the chance of our beating our best score drops close to zero," says Daniel Enber at Popular Science, and that's why newer sports (like swimming) tend to have their records broken more often than older sports (like running). Still, even if athletes never got faster or stronger, or if their training techniques never evolved, world records would still occasionally be broken, says Enber. That's because record breaking is still largely a randomized process, depending on variables as wildly different as an athlete's pregame mind-set and the day's weather.
How does technology affect breaking records?
Records are typically broken "during periods of major innovation," says Enber. In cycling, for example, the advent of carbon fiber bike frames coincided with a period when lots of records were shattered. Or in the case of swimming, the drag-reducing, high-tech bodysuits used in Beijing led to a number of lap times being smashed, subsequently causing officials to ban the suits in 2009. Anabolic steroids may have also played a role in making some records near-unbeatable, particularly in track. "Take Michael Johnson's 1996 record in the 400m dash," says George Dvorsky at io9. "No one has been able to touch it," and some people just assume that — because of a lack of anti-doping enforcement — performance-enhancing drugs played a part in Johnson's swiftness, though no formal accusations have ever been made against him.
What about training?
New techniques can considerably raise the bar for breaking records. In the high jump, for example, participants used to leap face down. Now they can go higher by flopping backwards. Another limitation to consider is a sport's accessibility. In an event like running, records are more difficult to break because the selection of world-class athletes is greater, says Nate Silver at The New York Times. Quite simply, it doesn't take much to strap on two shoes and go outside, and that's why record-breaking at track and field events has stagnated since the '90s. In a sport more dependent on a person's socioeconomic status, like swimming — which requires access to an Olympic-size pool, among other things — records appear to be broken more frequently because the sample size of athletes is considerably smaller.
Are we close to reaching the human limit?
Yes and no. In newer sports, new records will continually be set. In Olympic marathons, for example, women were only allowed to compete beginning in 1984. Since then, women have shaved 10 minutes off the world-record time; men, on the other hand, have only managed to shave off five minutes. Or take baseball: The .400 hitter all but disappeared once the color barrier was broken, because that raised the overall level of performance and made it more difficult for any one athlete to stand out. But that doesn't mean there won't be outliers. A number of studies have suggested that the limit of human capacity in track and field peaked in 1988, and that it would take 16 years to shave 0.16 seconds off the 100m dash record. "But then a strange thing happened," says io9's Dvorsky, "and his name was Usain Bolt." It just goes to show that records are still made to be broken.