Million Whys Press logo
Million Whys PressToronto
← Book 28 videos

Book 28, Question 104

How does goal-line technology know when a ball is fully inside the goal?

Some soccer games use cameras and sensors that follow the ball's position.

When the whole ball crosses the line, a signal goes to the referee's watch within a second, and it says goal. The system checks the ball's exact location many times a second. Humans can't always tell from far away, especially when players block the view.

Why I wrote this