How do they make the holes in Swiss cheese?
Swiss cheese is made in wheels of about 90 centimetres in diameter and 15 cm thick. The round holes inside the cheese are known as eyes in the industry. The eyes are about 1.6 cm wide and roughly 5 cm to 8 cm apart. They are produced by a build-up of pockets of gas from bacterial action.
Pure strains of certain bacterium are used to control the development of acid, eyes, and flavour. Bacteria inside the cheese produce large amounts of carbon dioxide gas. Pockets of the gas build up to form the round holes after six to eight weeks.
Why do cicadas make so much noise?
Cicadas are flying plant-feeding insects between three and five centimetres long, with a pair of membranous wings and big bulging eyes.
In most species of cicadas, it is only the males that make a loud, sometimes even deafening, buzzing noise that can be heard over a long distance. Only the males have ridged membranes called timbals on their abdomens which they vibrate to produce the buzzing. The abdomen has a hollow space that acts as a resonating chamber to amplify the sound.
Large groups of males will gather on high sunny branches to sing in 'choruses'. The singing will attract other males to join the group, and also silent females who go there to mate.
Males will produce different types of calls in different situations. There is an alarm call when picked up or startled; a calling song to attract both males and females to the chorus; and a courtship call when approaching and attempting to mate with females.
What are dreadlocks?
It is a hairstyle popularised by the early reggae players. Dreadlocks are cylindrically woven sections of uncombed hair twisted from scalp to end.
They are a common characteristic of the Rastafarian culture. But they can also be found on people of all races and creeds in countries far beyond the Caribbean. While dreadlocks are not necessarily religiously important, the hairstyle's roots are purely spiritual.
Dreadlocks can take years to grow. They are permanent and can only be removed by being cut off.
What is artificial intelligence?
It is the capacity of a digital computer or computer-controlled device to do work normally associated with the human brain, such as the ability to reason, discover meaning, generalise or learn from past experience.
The term is also often applied to the branch of computer science concerned with the development of systems that have such capabilities.
Research on artificial intelligence began soon after the development of the modern digital computer in the 1940s. Over the years, it has been shown that computers can be programmed to carry out very complex tasks - as for example playing chess - with great proficiency.