A scientific fact on Football referee's whistle ... How does a referee's whistle suddenly stop 22 players when 100,000 spectators are screaming in a football stadium? Here is the thriller behind it. Think of a World Cup football game. 100,000 fans. Ear-splitting cheers. 22 players are running at lightning speed in the middle of the field. At that moment, a player commits a foul. The referee blows the small whistle in his mouth. The next second - the sound cuts through all the cheers and makes all 22 people stand like statues. *How is this possible?* What is behind this is not an ordinary whistle, but a miracle of cutting-edge science. The whistles we used to buy when we were kids have a small iron ball rolling inside and making a noise. But the whistles used by FIFA referees do not have a ball. The whistle they use is called the Pea-less Whistle. When air enters and collides with the three Acoustic Chambers inside the whistle, harmonics sound is created at three different frequencies. That is why even if millions of people scream, it still reaches the players' ears sharply. This whistle, manufactured by the Molten VALKEEN company in Japan, is made of titanium. Water does not enter inside. Even if it rains, the sound does not change. There are even fans called directional fins on the sides to push the whistle sound towards the players. Do you know what is more interesting than this? Referees have a special training for blowing whistles. It is called the 'Tonguing Technique'. For a normal foul - a soft, moderate whistle. For a penalty, a loud, long whistle. For a red card, a violent whistle that makes the air explode! Players can understand the referee's mood by the sound of the whistle. #WA