Handball is a fast and awesome sport to watch or play after school or work. It is a game which requires skill, endurance and speed from its players who seem able to manipulate the ball in fantastic ways. Players serve, return and shoot the ball from impossible angles and with an agility that fascinates fans of the game everywhere.
Did you know? The 2007 National 4-Wall Handball Championships was held in Montreal.
Whether you play or watch the game, you have likely wondered how handball players hit or 'roll' the ball with such ease. Are there special properties about the balls which allow you to grip them while racing across the court; properties which cause the balls to bounce true and roll with such speed?
Of course! These 'special' properties may be attributed to science, in particular polymer chemistry! Dare I say that chemistry has a 'hand' in how handball is played!
Did you know? Court handball used to be called "fives" because the game was played with five fingers.
Court handball began in Ireland in the 1840s. At that time, handballs were made with a cork center and covered in horsehide. Can you imagine having to make a serve with a ball covered in horsehide? But this outer material had its problems. It expanded, stretched and changed shape in different temperatures.
Thankfully, science and technology came to the rescue with the introduction of rubber into the handball making process. Rubber turned out to be a much better material for maintaining a spherical shape, and also allowed the ball to fly at high speeds on a predictable path.
These days, handballs are made of natural or synthetic rubber, forming an inflatable hollow core. Natural and synthetic rubbers are alkene polymers. Natural rubber is harvested from a tree called Hevea brasiliensis; it is a polymer of a diene, isoprene (2-methyl-1,3-butadiene).
Did you know? Rubber naturally occurs as a milky suspension (called latex) in the sap of several varieties of plants and is tapped from trees just like maple syrup! Rubber can also be made synthetically.
Rubber's ability to stretch and contract is what makes this polymer so remarkable! The polymer chains contain double bonds that introduce bends and kinks into the chain.
When rubber is stretched, the randomly coiled chains straighten and orient themselves along the direction of the pull but the cross-links prevent the chains from sliding over each other. When rubber is released, this polymer returns to its original state in which the chains are orientated randomly.
The use of a rubber hollow centre is what makes the ball light, durable and flexible. These properties allow the ball to bounce higher and faster when you strike it and also provide flexibility and adhesiveness which make the balls easy to grip and control.
What could be worse than to be in mid-air, about to make your 'cut' or 'kill', only to have the ball slip from your fingers? Or worse yet, the ball simply thuds to the ground the moment you make contact with it? It is the elasticity and shape of the ball which allows the ball to accelerate when struck cleanly.
So the next time you play handball, consider how chemistry has contributed to the sport and how much it improves our game!
The official website for the Canadian Handball Association
Harlem Live: Handball
Carraher Jr, Charles E. Polymer News. Vol. 30, no. 8, pp. 257-260. Aug. 2005, "Polymers in Atheltics".
Samuel Lai. The Physics Factbook. Edited by Glenn Elert. "Mass of a Handball." Click here
Mills, Christopher; Sonntag, Jean-Marie. "Sports ball and method of manufacturing of same." click here
Organic Chemistry; John McMurry. 5th edition Brooks/Cole p. 261-262.
Sheila is presently completing her PhD in Chemistry at the University of Toronto and enjoys teaching science.