Football (ball)

The first balls were made of natural materials, such as an inflated pig bladder, later put inside a leather cover, which has given rise to the American slang-term "pigskin".

The oldest football still in existence, which is thought to have been made circa 1550, was discovered in the roof of Stirling Castle, Scotland, in 1981.

[3] It is roughly spherical[4] with a diameter of between 14–16 cm (5.5–6.3 in), weighs 125 g (4.4 oz) and is currently on display at the Smith Art Gallery and Museum[5][6] in Stirling.

Law 2 of the game specifies that the ball is an air-filled sphere with a circumference of 68–70 cm (27–28 in), a weight of 410–450 g (14–16 oz), inflated to a pressure of 0.6 to 1.1 atmospheres (60–111 kPa or 8.7–16.1 psi) "at sea level", and covered in leather or "other suitable material".

This configuration became common throughout Continental Europe in the 1960s, and was publicised worldwide by the Adidas Telstar, the official ball of the 1970 World Cup.

This design in often referenced when describing the truncated icosahedron Archimedean solid, carbon buckyballs, or the root structure of geodesic domes.

In 1860, Australian football pioneer Tom Wills argued that the oval rugby ball travelled further in the air and made for a more exciting game.

[15] Leather panels are typically tanned to a natural brown color, which is usually required in professional leagues and collegiate play.

Historically, white footballs have been used in games played at night so that the ball can be seen more easily[citation needed] however, improved artificial lighting conditions have made this no longer necessary.

The shape is generally credited to official Hugh "Shorty" Ray, who introduced the new ball in 1934 as a way to make the forward pass more effective.

In 1870 Richard Lindon and Bernardo Solano started making balls for Rugby school out of hand stitched, four-panel, leather casings and pigs' bladders.

[19] The introduction of synthetic footballs over the traditional leather balls, in both rugby codes, was originally governed by weather conditions.

[20] A referee will stop play immediately if the ball does not meet the requirements of size and shape.

[20] Traditionally made of brown leather, modern footballs are synthetic and manufactured in a variety of colours and patterns.