What's special about the 2014 World Cup ball?

The Ball of the World Cup 2014 is named Brazuca, produced by the famous sports firm Adidas.

So only a few days after the World Cup 2014 will officially take place, every stage of preparing for the biggest football tournament on the planet has been completed by the Brazilian host, including special balls used in matches. The Ball of the World Cup 2014 is named Brazuca , produced by the famous sports firm Adidas.

Learning from the Jabulani ball used in the 2010 World Cup, the Brazuca ball has undergone many tests before being put into production. Adidas has consulted from retired players like Zidane to contemporary stars such as Messi, Casillas, Van Persie . and invited more than 600 players from 10 different countries to participate in the ball test conducted throughout. 2 and a half years. They also secretly use it in some international matches and see the player's feedback.

Aerodynamic experts have pointed out three factors that can affect the path of the 2014 World Cup ball. The most important factor is the roughness of the ball surface, determined by the number of pieces. patched as well as seams between the patches, said Dr. Rabi Mehta of Ames Research Center (under NASA).

According to him, the so-called 'reversal effect' occurs when the ball does not swirl or spin very little while flying. When a ball is sewn, has a smooth surface that flies in the air and rotates negligible, the air near the surface of the ball is affected by the seams, creating an unbalanced movement. This imbalance creates forces that can suddenly affect the ball and create erratic drops. But 'when the ball swirls, we have the Magnus effect, the effect that makes the ball follow an arc orbit,' Mehta explained.

That's why it is impossible to predict the direction of the Jabulani because of its smoothness.'The more smooth the ball is, the more speed it will take for a reversal to occur . and coincidentally coincides with the speed of the ball in the World Cup football matches, about 80 - 88km / h, especially in situations. penalty kick , 'Dr Mehta explained.

Besides, according to Dr. Mehta, not only is it more rough, Brazuca's surface has small dots that are useful in the aerodynamic aspect and increase the friction between shoes and balls. But the big factor affecting the roughness is the shape of the seams. The Brazuca ball has only six pieces of rudder jigs attached, and Adidas said the shape of the new seam allows the ball to have aerodynamic accuracy, as well as a stable flight path.

Dr. Simon Choppin, of the Center for Sports Technical Research at Sheffield Hallam University (UK), conducted measurements of the Brazuca seams and said, although the number of pieces is less and makes the Brazuca available. it looks smoother, but in fact, Brazuca's roughness increases with other techniques.

After scanning the surface of the Jabulani and Brazuca with lasers to measure the seam thanks to 3D modeling technology, Choppin and his colleagues ' realized the depth of Janulani's seams at about 0.48mm, while this depth of Brazuca is 1.56mm. Besides, the total length of the seams on the Jabulani is about 203cm and this length in the Brazuca is about 327cm '.

According to Dr. Choppin, the deeper and longer seams make Brazuca more traditional. Wind tunnel tests also support this assertion. This means that in order to have a reversal effect with the Brazuca to create a nightmare for the goalkeeper, the players only need to create a velocity of about 48km / h.