Robots now outrun humans — but they still jump a metre short

The second World Humanoid Robot Games in Beijing produced a result that reads oddly when you put two of its events side by side. On the track, Tiangong Ultra took the 1500 m gold in 2 minutes 21 seconds. The human world record over that distance is 3:26.00, set by Hicham El Guerrouj in 1998 — and the machine's builder, the Beijing Innovation Center of Humanoid Robotics, headlined the result as beating the human mark by one minute and six seconds. In the long jump the same machine won as well, but with a very different picture: 7.97 m for gold, then 7.24 m and 7.19 m for the other two places on the podium. Mike Powell's human record has stood at 8.95 m since 1991. The robots beat us at running by a wide margin and lose the long jump by nearly a metre. That gap is not a fluke of one competition, it follows from how these legs are built. Running rewards a machine that can put power down continuously, cycle a limb quickly and stay upright — all things a torque-dense actuator with a fast control loop does well, and does without getting tired over the distance. A long jump is one single explosive extension, where the whole result is decided in the fraction of a second the foot spends on the board, and where a human athlete converts a full-speed approach into lift with tendons that store and release energy. Robot joints have no equivalent of that elastic return; a motor can only push as hard as its peak torque allows. The other number worth reading is the podium itself. All three long-jump medals went to the same model from the same team, and the centre's own bulletin claims the first four places. Its running total after 23 August was five golds, two silvers and six bronzes, including every athletics gold awarded that day. A clean sweep looks like dominance, and it partly is — but it also means the machines were mostly racing copies of themselves. At this stage of the sport, the standings measure how many units a well-funded lab can bring to the start line at least as much as they measure the state of the art.