The brain might lookhomogenousto thenaked eye, butit's actuallyfilled with an arrayofcelltypes, each of which expresses adistinct set ofgenesdepending onitspreciselocation.
While both CAIROS and GoalRef use magnetic fields around the goal and need to insert a chip in the ball, Hawk-Eye and GoalControl use a 3D imaging system to determine the preciselocation of the ball.