So as Nilav is lucky enough to be in Mountain view right now, the FIFA world cup, not held far from where he lives is being held in Brazil. So all Football fans will know about the debate that has been going on for over 50 years about the 1966 world cup finals. Did the ball cross the line or not. So this time, the first time in the world cup goal line technology will be used. Goal line technology determines whether the ball crosses the goal line or not. So there is a system developed by a company called GoalControl which has put 14 cameras all around the stadium, focusing on the goals. It captures a three dimensional position of the ball with high precision. When ball passes the line a vibration and optical signal is sent to watches worn by the refrees. In less than a second they can know if its a goal or not. Vanishing spray is being used to prevent enroachment by defenders making up walls during free kicks. Vanishing spray is a shaving cream like foam which the referee sprays in front of the wall to ensure that the players are standing 10 yards away.
Here are some pictures-


Here are some pictures-