Why are the balls of each World Cup different?

Looking at this question from a perspective of learning can give you an interesting answer.

Why are the World Cup balls different every year? Physics professor John Eric Goff of Lynchburg University and the author of the book 'Gold Medal Physics: The Science of Sports' recently explained this interesting question in a scientific perspective. In fact, all the changes applied every year are not the best and it even causes more problems.

For football, one of the prerequisites is to make it as round as possible. Previously, we often saw the ball associated with black-and-white images interspersed with 20 hexagonal leather pieces and 12 pentagonal pieces combined. They create the most approximate circle shape when joined together. However, since the 2006 World Cup, people have devised more creative ways to create the ball's circle.

Teamgeist Ball of World Cup 2006 (Germany).

New technology allows Adidas to create balls with fewer pieces. Few pieces mean less parts and the ball will have a smoother surface.'When the ball has a smooth surface, the level of air resistance will increase. It's like your friend kicked a beach ball, ' said John Eric Goff. That's what happened to the Teamgeist ball of the 2006 World Cup. The players that year repeatedly complained that the ball did not follow the creation fund they expected. So in 2010, Adidas corrected the error by adding some textures to create a more rugged surface for the ball. Is the problem solved?

Jabulani Ball of the World Cup 2010 (South Africa).

However, the 2010 Jabulani ball of the World Cup is a failure because it is not round enough. When kicking at certain speeds, you will see this ball abruptly slow down in the direction of flight.

In 2014, the number of pieces on the World Cup ball continued to decrease (less than two pieces) but Adidas confirmed that the length of the balls on this ball is 68% longer than the previous ball. Thus, this ball still has an acceptable roundness while flying farther than the 2010 ball.

Left Brazuca (World Cup 2014 - Brazil) and Telstar 18 (2018 World Cup - Russia).

For Telstar 18 (in the knockout round, Telstar Mechta), this ball has a 30% longer area of ​​the ledge than what was on the Brazuca (World Cup 2014). 'So this ball may be a bit rough, although Adidas has made up for this by making it more shallow , ' said John. However, some experiments show that Telstar balls have similar Brazuca characteristics .

John also identified the biggest reason behind each World Cup having a different ball could be money. The 2018 World Cup ball costs up to $ 100, much higher than the average price of $ 20 of a football. However, it is fair to say that this is still a ball with many interesting technologies. Besides the NFC chip, its pieces are also attached together by heat. This mechanism prevents water from penetrating the inside of the ball, holding water and can make the ball heavier.