Diving into data from the recent Olympic Games, scientists have discovered a disturbing trend in the swimming competition, The Washington Post reports. In longer races, swimmers in lanes one through three swam their outbound lengths faster than their inbound ones, whereas those in lanes six through eight did just the opposite. Only in lanes four and five did swimmers traverse the pool in equal times both ways. That suggests a current may have been circulating in the pool: away from the starting blocks in the low-numbered lanes and toward them in the high-numbered ones. Such a current could have been decisive in the 50-meter freestyle, a mad dash of one length. Even in longer races, it could have slowed swimmers in the outer lanes, because they would have spent more time swimming at the slower speed (against the current) than at the faster speed (with the current).