• Tue
  • Sep 2, 2014
  • Updated: 6:52pm

Ask Mr Brain...all will be explained

PUBLISHED : Tuesday, 13 July, 1999, 12:00am
UPDATED : Tuesday, 13 July, 1999, 12:00am
 

Do ants sleep? Some insects spend the winter in a torpid state, and at least some insects - including some ants - exhibit sleep-like behaviour day to day.


Workers of a nocturnal Australian carpenter ant species, camponotus perthiana, were observed lying on their sides in the pupal position during the day.


The ants could be 'wakened' by gentle probing with forceps, and they moved around sluggishly before starting the typical swift movements of a worker ant.


However, they may not have been sleeping but just lying down on the job. At any given moment, only a very small fraction of the workers in the typical ant colony are at work foraging.


Inside the nest, most of the workers are standing still, grooming themselves or just walking around. Researchers suggest that some of the idle ants are either excess workers awaiting new jobs or reserve forces, available for a nest-wide crisis such as a flood or an invasion or just a heavy workload.


How much fuel does the space shuttle use for takeoff? At liftoff, the shuttle, with all its fuel, weighs more than 2,000 tonnes. In the first two minutes of liftoff, each of its two solid-fuel rocket boosters uses 499 tonnes of fuel. The boosters are then ejected from the shuttle and fall into the ocean attached to parachutes.


Meanwhile, 2.272 million litres of liquid fuel are being used up in the first eight-and-a-half minutes. That's how long it takes for the shuttle's three engines to get the spacecraft into orbit. After that time, the shuttle orbits the earth once every 90 minutes, travelling at 28,000 kilometres an hour.


How is the human voice produced, and what makes an individual's voice distinctive? Many factors shape an individual's voice. The basic sound is produced by vibrations of the vocal cords, which are folds of muscles and ligaments inside the neck, as air from the lungs blows through them.


But that's only the beginning, said Charles Diggs, a speech therapist with the American Speech, Language and Hearing Association.


After the voice box generates the sound, the chamber formed by the upper throat, the mouth, the tongue and the lips causes the vocal sound to resonate in a way that's unique to each individual - in much the same way that the shape of different musical instruments results in a different sound.


Men's vocal cords are more massive and vibrate at a lower frequency than women's, which makes men's voices lower.


A good singing voice reflects many factors, including the size of the individual's chest cavity and vocal cords, the ability to shape the sound to the correct pitch with muscles of the vocal tract, and the natural conformation of the resonating chamber formed by the upper throat and mouth.


As with other types of music, a singer needs a 'good instrument' - the structures that generate and colour the voice - as well as the ability to use those structures to their best advantage.


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