During the 1986 FIFA World Cup quarterfinal football match Argentina’s captain, Diego Maradona, saw an opportunity when England’s goalkeeper emerged from the box. He scored the first goal of the game…by hitting the ball into the box with his hand. Millions of fans saw the illegal handball live and on TV, but the person who mattered most—the referee—did not. The goal counted, Argentina won the match 2-1, and the team went on to win the World Cup.
Asked afterward how he scored the goal, Maradona quipped, "Un poco con la cabeza de Maradona y otro poco con la mano de Dios," which means "a little with the head of Maradona, and a little with the hand of God."
Everyone knew the hand belonged to Maradona, not God, and yet players, fans, and TV networks all had to accept the final, flawed authority of one individual in a fast-paced match.
Twenty-five years later, it happened again: This time a referee disallowed a clear goal by England during a 2010 World Cup game against Germany. After that embarrassment, FIFA approved use of Goal Line Technology—a high-speed camera and image-processing network that continuously captures the ball’s location in 3D, sending a notification to the referee’s watch whenever the goal line is crossed. They also approved Video Assistant Referees (VAR)—off-pitch officials who review video and alert referees to on-field mistakes, but only in cases of “clear and obvious error.”
Today, nearly every sport uses sensor or imaging technology to monitor finish lines, verify goals or points, and enforce line boundaries. And sports technology is not limited to official calls. It’s now infiltrated every aspect of sports and performance, from the casual athlete to the elite, in the form of sensors that measure, analyze, correct, and even coach.
This issue of Photonics Focus explores optics technologies in sports, from markerless motion capture systems that track athletes’ movements without suits or sensors, to the next generation of wearables that measure athletes’ biometrics—everything from lactate levels to body temperature—in real time.
While this issue highlights multisensor technology to help players perform better, recover faster, and train smarter, the cameras and sensors trained on the field of play have a more single-minded mission: To see what human referees cannot. They don’t blink. They don’t play favorites. Data is data. And yet, sports are as contentious as ever. Now, instead of arguing about whether the referee saw the call correctly, we vehemently debate whether the incident merits the “clear and obvious” threshold for VAR review. Or, we argue about how placement of the cameras or sensors may have accounted for the millimeter measurement that made or lost the game. We even bicker about the name of the sport itself: soccer or football.
Conflict is an enduring cultural component of sport, intertwined with national pride, identity, and even historical grievances. When Maradona punched that ball into the goal box, Argentina and England were just four years removed from the Falklands War, a conflict where Argentinian forces suffered a humiliating and painful defeat. In this context, the hand of God may have intervened not to win a soccer game, but to salve a frustrated nation.
Sports technology will undoubtedly improve individual performances and make game calls more accurate, but will it fundamentally change the games? I’d argue no: The games athletes play will always be about the heart as much as the head. Technology can measure the ball’s position, but it can never measure the weight of the hand of God.
Gwen Weerts, Editor-in-chief
