Seven cameras track the ball from every angle. (FIFA image) The 2015 FIFA Women’s World Cup, currently underway in Canada, is drawing record television audiences around the world. It’s also another milestone for goal-line technology (GLT), which is quickly gaining acceptance. In the group stage, which ended on 17 June, FIFA reports that GLT was used to award goals by Mexico in a 1-1 draw with Colombia, by Thailand in a 3-2 win over Ivory Coast, and by Costa Rica in a 2-2 draw with Korea. Also, it confirmed a save (no goal) on a header by Meghan Klingenberg in the USA-Sweden game, a scoreless draw. The Hawk-Eye GLT system consists of seven cameras positioned strategically at each end of the stadium, to track the ball precisely from every angle. Within one second of a play at the goal line, a signal is relayed to the referee’s watch to confirm the goal. It is reputed to be accurate within 1 mm. Hawk-Eye was selected for this year's tournament in March . Last...